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| http://people.csail.mit.edu/jaffer/convect/pllcal |
Wind-tunnel calibration |
The correspondence between fan rotation rate and test chamber airspeed was first determined using an "Ambient Weather WM-2", which specifies an accuracy of ±3% of reading.
Airspeeds slower than 2 m/s should be nearly proportional to the fan rotation rate.
The WM-2 anemometer measures the rate of rotation of its blades. When the wind stops, the rotor slows before stopping abruptly. Thus, the rotor bearings have dry friction. Dry friction induces torque counter to the wind-induced rotation, which slows the rotation rate by a fixed amount.
As can be seen in the graphs below, the WM-2 has two different slopes for its measurements, transitioning near 1.725 m/s. The blue curve in the graphs is the expected speed u when u≥1.725; and 1.477 u−0.81 otherwise.
The upper portion of the blue trace curves upward because of a mistake in the apparatus software which undercounted rotations when w > 1200. It is modeled by the blue curve taking [w−6 − 1750−6]−1/6 instead of w as the fan rotation rate.
The red trace is the theoretical windspeed along the surface-under-test.
The banner line has the UTC starting time of the dataset, centigrade temperature, relative humidity, atmospheric pressure, anemometer model, and a tag for the wind-tunnel configuration. The Lnorm line is the formula of the theoretical windspeed (red trace); w is fan rotations per minute. Lnorm(p,x,y)=[xp+yp]1/p
The table columns are: fan rotations per minute, the measured and predicted windspeed in m/s, and their individual relative error "RE". The root-mean-squared relative-error "RMSRE", "bias", and "scatter" are of the cumulative measurements; the "used" column gives the number of measurements in the cumulative statistics, "/", and the total number of measurements.
The plate was suspended facing down in the wind-tunnel.
20160420T031230 16.82C 37.3% 101495Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1400.0 4.426 4.347 +1.81% 1.81% +1.81% 0.00% 1/23 1350.0 4.202 4.205 -0.07% 1.28% +0.87% 0.94% 2/23 1300.0 4.157 4.067 +2.23% 1.66% +1.32% 1.00% 3/23 1250.0 3.889 3.931 -1.06% 1.53% +0.73% 1.35% 4/23 1200.0 3.800 3.796 +0.09% 1.37% +0.60% 1.23% 5/23 1150.0 3.710 3.662 +1.33% 1.36% +0.72% 1.16% 6/23 1100.0 3.487 3.526 -1.12% 1.33% +0.46% 1.25% 7/23 1050.0 3.353 3.390 -1.09% 1.30% +0.26% 1.28% 8/23 1000.0 3.129 3.252 -3.77% 1.76% -0.18% 1.75% 9/23 950.0 3.085 3.112 -0.87% 1.69% -0.25% 1.67% 10/23 900.0 2.660 2.969 -10.42% 3.53% -1.18% 3.33% 11/23 850.0 2.772 2.824 -1.86% 3.42% -1.23% 3.19% 12/23 800.0 2.392 2.677 -10.65% 4.42% -1.96% 3.96% 13/23 750.0 2.369 2.526 -6.22% 4.57% -2.26% 3.97% 14/23 700.0 2.101 2.373 -11.48% 5.32% -2.88% 4.47% 15/23 650.0 2.146 2.218 -3.24% 5.21% -2.90% 4.33% 16/23 600.0 2.034 2.059 -1.22% 5.07% -2.80% 4.22% 17/23 550.0 1.967 1.898 +3.64% 5.00% -2.44% 4.36% 18/23 500.0 1.632 1.734 -5.92% 5.05% -2.63% 4.31% 19/23 450.0 1.498 1.506 -0.57% 4.92% -2.52% 4.23% 20/23 400.0 1.207 1.258 -4.03% 4.88% -2.59% 4.14% 21/23 350.0 0.983 1.006 -2.24% 4.80% -2.58% 4.04% 22/23 300.0 0.715 0.752 -4.86% 4.80% -2.68% 3.98% 23/23
Sequential WM-2 readings vary significantly. The subsequent WM-2 measurements use the value which is most frequent over a 10 s interval.
20160508T181015 17.61C 45.8% 99736Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1400.0 4.470 4.347 +2.84% 2.84% +2.84% 0.00% 1/12 1300.0 4.247 4.067 +4.43% 3.72% +3.63% 0.80% 2/12 1200.0 3.889 3.796 +2.45% 3.35% +3.24% 0.86% 3/12 1100.0 3.576 3.526 +1.42% 2.98% +2.78% 1.08% 4/12 1000.0 3.129 3.252 -3.77% 3.16% +1.47% 2.79% 5/12 900.0 2.906 2.969 -2.14% 3.01% +0.87% 2.88% 6/12 800.0 2.638 2.677 -1.46% 2.84% +0.54% 2.79% 7/12 700.0 2.325 2.373 -2.06% 2.76% +0.21% 2.75% 8/12 600.0 2.190 2.059 +6.38% 3.36% +0.90% 3.24% 9/12 500.0 1.743 1.734 +0.53% 3.19% +0.86% 3.07% 10/12 400.0 1.296 1.258 +3.08% 3.18% +1.06% 3.00% 11/12 300.0 0.760 0.752 +1.09% 3.06% +1.07% 2.87% 12/12
20160511T231118 17.24C 41.9% 101361Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1400.0 4.426 4.347 +1.81% 1.81% +1.81% 0.00% 1/13 1300.0 4.202 4.067 +3.33% 2.68% +2.57% 0.76% 2/13 1200.0 3.934 3.796 +3.63% 3.03% +2.92% 0.80% 3/13 1100.0 3.353 3.526 -4.92% 3.60% +0.96% 3.46% 4/13 1000.0 3.085 3.252 -5.14% 3.95% -0.26% 3.94% 5/13 900.0 2.861 2.969 -3.64% 3.90% -0.82% 3.81% 6/13 800.0 2.570 2.677 -3.97% 3.91% -1.27% 3.70% 7/13 700.0 2.280 2.373 -3.94% 3.92% -1.61% 3.57% 8/13 600.0 2.123 2.059 +3.12% 3.84% -1.08% 3.68% 9/13 500.0 1.676 1.734 -3.34% 3.79% -1.31% 3.56% 10/13 400.0 1.162 1.258 -7.58% 4.28% -1.88% 3.84% 11/13 300.0 0.760 0.752 +1.09% 4.11% -1.63% 3.77% 12/13 250.0 0.492 0.495 -0.69% 3.95% -1.56% 3.63% 13/13
20160519T014352 17.25C 47.3% 101643Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1350.0 4.336 4.205 +3.12% 3.12% +3.12% 0.00% 1/13 1300.0 4.113 4.067 +1.13% 2.35% +2.13% 1.00% 2/13 1200.0 3.755 3.796 -1.08% 2.02% +1.06% 1.72% 3/13 1100.0 3.532 3.526 +0.15% 1.75% +0.83% 1.54% 4/13 1000.0 3.219 3.252 -1.02% 1.63% +0.46% 1.56% 5/13 900.0 2.928 2.969 -1.38% 1.59% +0.15% 1.58% 6/13 800.0 2.638 2.677 -1.46% 1.57% -0.08% 1.57% 7/13 700.0 2.280 2.373 -3.94% 2.03% -0.56% 1.95% 8/13 600.0 2.168 2.059 +5.29% 2.60% +0.09% 2.60% 9/13 500.0 1.743 1.734 +0.53% 2.47% +0.13% 2.47% 10/13 400.0 1.252 1.258 -0.47% 2.36% +0.08% 2.36% 11/13 300.0 0.760 0.752 +1.09% 2.28% +0.16% 2.28% 12/13 250.0 0.492 0.495 -0.69% 2.20% +0.10% 2.20% 13/13
20160519T015400 17.25C 47.3% 101643Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.202 4.067 +3.33% 3.33% +3.33% 0.00% 1/11 1200.0 3.934 3.796 +3.63% 3.48% +3.48% 0.15% 2/11 1100.0 3.442 3.526 -2.39% 3.16% +1.52% 2.77% 3/11 1000.0 3.196 3.252 -1.70% 2.86% +0.72% 2.77% 4/11 900.0 2.906 2.969 -2.14% 2.73% +0.15% 2.73% 5/11 800.0 2.548 2.677 -4.81% 3.17% -0.68% 3.10% 6/11 700.0 2.235 2.373 -5.83% 3.67% -1.41% 3.39% 7/11 600.0 2.146 2.059 +4.21% 3.74% -0.71% 3.68% 8/11 500.0 1.743 1.734 +0.53% 3.53% -0.57% 3.49% 9/11 400.0 1.252 1.258 -0.47% 3.36% -0.56% 3.31% 10/11 300.0 0.760 0.752 +1.09% 3.22% -0.41% 3.19% 11/11
20160527T011044 18.61C 52.5% 101436Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.068 4.067 +0.03% 0.03% +0.03% 0.00% 1/10 1200.0 3.845 3.796 +1.27% 0.90% +0.65% 0.62% 2/10 1100.0 3.666 3.526 +3.95% 2.40% +1.75% 1.64% 3/10 1000.0 3.263 3.252 +0.36% 2.08% +1.40% 1.54% 4/10 900.0 2.906 2.969 -2.14% 2.09% +0.69% 1.98% 5/10 800.0 2.682 2.677 +0.21% 1.91% +0.61% 1.81% 6/10 700.0 2.325 2.373 -2.06% 1.93% +0.23% 1.92% 7/10 600.0 2.190 2.059 +6.38% 2.89% +1.00% 2.71% 8/10 500.0 1.743 1.734 +0.53% 2.73% +0.95% 2.56% 9/10 400.0 1.274 1.258 +1.31% 2.62% +0.98% 2.43% 10/10
20160528T202907 17.88C 53.1% 101339Pa +90 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1200.0 3.800 3.796 +0.09% 0.09% +0.09% 0.00% 1/10 1100.0 3.576 3.526 +1.42% 1.00% +0.76% 0.66% 2/10 1000.0 3.330 3.252 +2.42% 1.62% +1.31% 0.95% 3/10 900.0 2.995 2.969 +0.87% 1.47% +1.20% 0.85% 4/10 800.0 2.682 2.677 +0.21% 1.32% +1.00% 0.86% 5/10 700.0 2.392 2.373 +0.77% 1.24% +0.96% 0.79% 6/10 600.0 2.190 2.059 +6.38% 2.67% +1.74% 2.03% 7/10 500.0 1.699 1.734 -2.05% 2.60% +1.26% 2.27% 8/10 400.0 1.296 1.258 +3.08% 2.66% +1.47% 2.22% 9/10 300.0 0.805 0.752 +7.04% 3.36% +2.02% 2.69% 10/10
20160530T010747 18.21C 58.0% 101870Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.157 4.067 +2.23% 2.23% +2.23% 0.00% 1/11 1200.0 3.800 3.796 +0.09% 1.58% +1.16% 1.07% 2/11 1100.0 3.576 3.526 +1.42% 1.53% +1.25% 0.88% 3/11 1000.0 3.219 3.252 -1.02% 1.42% +0.68% 1.24% 4/11 900.0 3.040 2.969 +2.38% 1.65% +1.02% 1.30% 5/11 800.0 2.593 2.677 -3.14% 1.98% +0.33% 1.95% 6/11 700.0 2.347 2.373 -1.12% 1.88% +0.12% 1.88% 7/11 600.0 2.146 2.059 +4.21% 2.30% +0.63% 2.22% 8/11 500.0 1.743 1.734 +0.53% 2.18% +0.62% 2.09% 9/11 400.0 1.274 1.258 +1.31% 2.11% +0.69% 1.99% 10/11 300.0 0.760 0.752 +1.09% 2.04% +0.73% 1.90% 11/11
20160603T201759 18.98C 54.2% 101262Pa +90 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.023 4.067 -1.07% 1.07% -1.07% 0.00% 1/11 1200.0 3.710 3.796 -2.26% 1.77% -1.67% 0.60% 2/11 1100.0 3.487 3.526 -1.12% 1.58% -1.48% 0.55% 3/11 1000.0 3.219 3.252 -1.02% 1.46% -1.37% 0.52% 4/11 900.0 2.906 2.969 -2.14% 1.62% -1.52% 0.56% 5/11 800.0 2.548 2.677 -4.81% 2.46% -2.07% 1.33% 6/11 700.0 2.190 2.373 -7.71% 3.70% -2.87% 2.32% 7/11 600.0 2.079 2.059 +0.95% 3.47% -2.40% 2.52% 8/11 500.0 1.699 1.734 -2.05% 3.35% -2.36% 2.37% 9/11 400.0 1.252 1.258 -0.47% 3.18% -2.17% 2.32% 10/11 300.0 0.715 0.752 -4.86% 3.36% -2.41% 2.35% 11/11
20160807T141025 22.94C 58.3% 100763Pa +90 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.202 4.067 +3.33% 3.33% +3.33% 0.00% 1/11 1200.0 3.889 3.796 +2.45% 2.92% +2.89% 0.44% 2/11 1100.0 3.576 3.526 +1.42% 2.52% +2.40% 0.78% 3/11 1000.0 3.398 3.252 +4.48% 3.13% +2.92% 1.13% 4/11 900.0 2.950 2.969 -0.63% 2.81% +2.21% 1.74% 5/11 800.0 2.503 2.677 -6.48% 3.69% +0.76% 3.61% 6/11 700.0 2.302 2.373 -3.00% 3.60% +0.22% 3.59% 7/11 600.0 2.146 2.059 +4.21% 3.68% +0.72% 3.61% 8/11 500.0 1.699 1.734 -2.05% 3.53% +0.41% 3.51% 9/11 400.0 1.185 1.258 -5.80% 3.82% -0.21% 3.82% 10/11 300.0 0.715 0.752 -4.86% 3.93% -0.63% 3.88% 11/11
20160807T142002 22.97C 59.5% 100682Pa +90 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.157 4.067 +2.23% 2.23% +2.23% 0.00% 1/11 1200.0 3.889 3.796 +2.45% 2.34% +2.34% 0.11% 2/11 1100.0 3.576 3.526 +1.42% 2.08% +2.03% 0.44% 3/11 1000.0 3.353 3.252 +3.11% 2.38% +2.30% 0.60% 4/11 900.0 2.995 2.969 +0.87% 2.16% +2.02% 0.79% 5/11 800.0 2.660 2.677 -0.63% 1.99% +1.57% 1.22% 6/11 700.0 2.235 2.373 -5.83% 2.87% +0.52% 2.82% 7/11 600.0 2.101 2.059 +2.04% 2.78% +0.71% 2.69% 8/11 500.0 1.699 1.734 -2.05% 2.71% +0.40% 2.68% 9/11 400.0 1.229 1.258 -2.25% 2.67% +0.14% 2.66% 10/11 300.0 0.760 0.752 +1.09% 2.56% +0.22% 2.55% 11/11
20160810T235346 21.85C 62.1% 101606Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.247 4.067 +4.43% 4.43% +4.43% 0.00% 1/11 1200.0 3.979 3.796 +4.80% 4.62% +4.61% 0.19% 2/11 1100.0 3.666 3.526 +3.95% 4.41% +4.39% 0.35% 3/11 1000.0 3.398 3.252 +4.48% 4.43% +4.42% 0.30% 4/11 900.0 2.995 2.969 +0.87% 3.98% +3.71% 1.44% 5/11 800.0 2.682 2.677 +0.21% 3.63% +3.12% 1.85% 6/11 700.0 2.414 2.373 +1.71% 3.42% +2.92% 1.79% 7/11 600.0 2.190 2.059 +6.38% 3.92% +3.35% 2.02% 8/11 500.0 1.788 1.734 +3.11% 3.84% +3.33% 1.91% 9/11 400.0 1.296 1.258 +3.08% 3.77% +3.30% 1.81% 10/11 300.0 0.760 0.752 +1.09% 3.61% +3.10% 1.84% 11/11
The plate was flipped over, causing the test surface to ride higher in the test chamber. The Bernoulli principle caused flow over the test surface to increase about 4%. The prediction traces are scaled by 1.04.
upward-facing
20160813T015611 21.07C 55.2% 100759Pa -90 WM-2 *1.0400 orig 3mm r/min measure predict RE RMSRE bias scatter used 1300.0 4.202 4.230 -0.65% 0.65% -0.65% 0.00% 1/11 1200.0 3.889 3.948 -1.49% 1.15% -1.07% 0.42% 2/11 1100.0 3.621 3.667 -1.26% 1.19% -1.13% 0.36% 3/11 1000.0 3.353 3.382 -0.86% 1.12% -1.07% 0.33% 4/11 900.0 2.950 3.088 -4.45% 2.23% -1.74% 1.39% 5/11 800.0 2.682 2.784 -3.65% 2.52% -2.06% 1.45% 6/11 700.0 2.325 2.468 -5.83% 3.21% -2.60% 1.88% 7/11 600.0 2.146 2.142 +0.20% 3.00% -2.25% 1.99% 8/11 500.0 1.743 1.804 -3.34% 3.04% -2.37% 1.91% 9/11 400.0 1.207 1.340 -9.95% 4.27% -3.13% 2.90% 10/11 300.0 0.715 0.814 -12.16% 5.48% -3.95% 3.80% 11/11
20160828T191641 22.06C 52.7% 101881Pa -90 WM-2 *1.0400 orig 3mm r/min measure predict RE RMSRE bias scatter used 1200.0 3.934 3.948 -0.36% 0.36% -0.36% 0.00% 1/10 1100.0 3.710 3.667 +1.17% 0.87% +0.41% 0.77% 2/10 1000.0 3.308 3.382 -2.18% 1.44% -0.46% 1.37% 3/10 900.0 2.950 3.088 -4.45% 2.55% -1.45% 2.10% 4/10 800.0 2.682 2.784 -3.65% 2.81% -1.89% 2.07% 5/10 700.0 2.280 2.468 -7.64% 4.04% -2.85% 2.86% 6/10 600.0 2.190 2.142 +2.29% 3.83% -2.12% 3.20% 7/10 500.0 1.788 1.804 -0.86% 3.60% -1.96% 3.02% 8/10 400.0 1.252 1.340 -6.61% 4.05% -2.48% 3.20% 9/10 300.0 0.760 0.814 -6.67% 4.38% -2.90% 3.29% 10/10
20160828T192700 22.13C 52.7% 101907Pa -90 door-closed WM-2 *1.0400 orig 3mm r/min measure predict RE RMSRE bias scatter used 1200.0 3.934 3.948 -0.36% 0.36% -0.36% 0.00% 1/10 1100.0 3.666 3.667 -0.05% 0.26% -0.20% 0.16% 2/10 1000.0 3.353 3.382 -0.86% 0.54% -0.42% 0.33% 3/10 900.0 3.040 3.088 -1.56% 0.91% -0.71% 0.57% 4/10 800.0 2.727 2.784 -2.04% 1.22% -0.97% 0.74% 5/10 700.0 2.369 2.468 -4.01% 1.98% -1.48% 1.32% 6/10 600.0 2.146 2.142 +0.20% 1.84% -1.24% 1.36% 7/10 500.0 1.654 1.804 -8.29% 3.40% -2.12% 2.66% 8/10 400.0 1.252 1.340 -6.61% 3.89% -2.62% 2.87% 9/10 300.0 0.760 0.814 -6.67% 4.25% -3.03% 2.98% 10/10
downward-facing
20160828T203416 21.20C 50.6% 101854Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1400.0 4.470 4.347 +2.84% 2.84% +2.84% 0.00% 1/12 1300.0 4.202 4.067 +3.33% 3.09% +3.08% 0.25% 2/12 1200.0 3.800 3.796 +0.09% 2.52% +2.09% 1.42% 3/12 1100.0 3.576 3.526 +1.42% 2.30% +1.92% 1.27% 4/12 1000.0 3.219 3.252 -1.02% 2.11% +1.33% 1.63% 5/12 900.0 2.950 2.969 -0.63% 1.94% +1.00% 1.66% 6/12 800.0 2.638 2.677 -1.46% 1.88% +0.65% 1.76% 7/12 700.0 2.280 2.373 -3.94% 2.24% +0.08% 2.24% 8/12 600.0 2.146 2.059 +4.21% 2.54% +0.54% 2.48% 9/12 500.0 1.743 1.734 +0.53% 2.41% +0.54% 2.35% 10/12 400.0 1.252 1.258 -0.47% 2.31% +0.44% 2.26% 11/12 300.0 0.760 0.752 +1.09% 2.23% +0.50% 2.17% 12/12
20160829T015736 22.17C 51.4% 101803Pa -90 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.694 4.654 +0.85% 0.85% +0.85% 0.00% 1/13 1400.0 4.426 4.347 +1.81% 1.41% +1.33% 0.48% 2/13 1300.0 4.023 4.067 -1.07% 1.31% +0.53% 1.20% 3/13 1200.0 3.845 3.796 +1.27% 1.30% +0.72% 1.08% 4/13 1100.0 3.599 3.526 +2.05% 1.48% +0.98% 1.11% 5/13 1000.0 3.219 3.252 -1.02% 1.41% +0.65% 1.26% 6/13 900.0 2.995 2.969 +0.87% 1.35% +0.68% 1.17% 7/13 800.0 2.638 2.677 -1.46% 1.37% +0.41% 1.30% 8/13 700.0 2.325 2.373 -2.06% 1.46% +0.14% 1.45% 9/13 600.0 2.101 2.059 +2.04% 1.53% +0.33% 1.49% 10/13 500.0 1.699 1.734 -2.05% 1.58% +0.11% 1.58% 11/13 400.0 1.207 1.258 -4.03% 1.91% -0.23% 1.89% 12/13 300.0 0.760 0.752 +1.09% 1.86% -0.13% 1.85% 13/13
20160910T233913 21.12C 56.4% 101294Pa +90 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.694 4.654 +0.85% 0.85% +0.85% 0.00% 1/13 1400.0 4.381 4.347 +0.78% 0.82% +0.82% 0.04% 2/13 1300.0 4.202 4.067 +3.33% 2.03% +1.65% 1.18% 3/13 1200.0 3.889 3.796 +2.45% 2.14% +1.85% 1.08% 4/13 1100.0 3.576 3.526 +1.42% 2.02% +1.76% 0.98% 5/13 1000.0 3.286 3.252 +1.05% 1.89% +1.65% 0.94% 6/13 900.0 3.018 2.969 +1.63% 1.86% +1.64% 0.87% 7/13 800.0 2.682 2.677 +0.21% 1.74% +1.46% 0.94% 8/13 700.0 2.325 2.373 -2.06% 1.78% +1.07% 1.42% 9/13 600.0 2.168 2.059 +5.29% 2.38% +1.49% 1.85% 10/13 500.0 1.699 1.734 -2.05% 2.35% +1.17% 2.03% 11/13 400.0 1.207 1.258 -4.03% 2.53% +0.74% 2.42% 12/13 300.0 0.715 0.752 -4.86% 2.78% +0.31% 2.76% 13/13
20160911T233742 21.34C 53.9% 101479Pa +0 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.739 4.654 +1.81% 1.81% +1.81% 0.00% 1/13 1400.0 4.470 4.347 +2.84% 2.38% +2.32% 0.51% 2/13 1300.0 4.202 4.067 +3.33% 2.73% +2.66% 0.63% 3/13 1200.0 3.934 3.796 +3.63% 2.98% +2.90% 0.69% 4/13 1100.0 3.710 3.526 +5.22% 3.54% +3.36% 1.11% 5/13 1000.0 3.398 3.252 +4.48% 3.72% +3.55% 1.10% 6/13 900.0 3.085 2.969 +3.89% 3.74% +3.60% 1.02% 7/13 800.0 2.727 2.677 +1.88% 3.56% +3.38% 1.11% 8/13 700.0 2.347 2.373 -1.12% 3.38% +2.88% 1.76% 9/13 600.0 2.146 2.059 +4.21% 3.47% +3.02% 1.72% 10/13 500.0 1.721 1.734 -0.76% 3.32% +2.67% 1.96% 11/13 400.0 1.252 1.258 -0.47% 3.18% +2.41% 2.07% 12/13 300.0 0.849 0.752 +12.98% 4.72% +3.22% 3.45% 13/13
20160921T234308 21.10C 63.8% 101946Pa +0 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.694 4.654 +0.85% 0.85% +0.85% 0.00% 1/13 1400.0 4.381 4.347 +0.78% 0.82% +0.82% 0.04% 2/13 1300.0 4.202 4.067 +3.33% 2.03% +1.65% 1.18% 3/13 1200.0 3.889 3.796 +2.45% 2.14% +1.85% 1.08% 4/13 1100.0 3.666 3.526 +3.95% 2.61% +2.27% 1.28% 5/13 1000.0 3.308 3.252 +1.73% 2.48% +2.18% 1.19% 6/13 900.0 3.085 2.969 +3.89% 2.73% +2.43% 1.25% 7/13 800.0 2.705 2.677 +1.04% 2.58% +2.25% 1.26% 8/13 700.0 2.325 2.373 -2.06% 2.53% +1.77% 1.80% 9/13 600.0 2.190 2.059 +6.38% 3.13% +2.23% 2.20% 10/13 500.0 1.788 1.734 +3.11% 3.13% +2.31% 2.11% 11/13 400.0 1.252 1.258 -0.47% 3.00% +2.08% 2.16% 12/13 300.0 0.760 0.752 +1.09% 2.90% +2.00% 2.09% 13/13
20160925T150355 19.69C 55.5% 101739Pa +0 +0 WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.560 4.654 -2.03% 2.03% -2.03% 0.00% 1/13 1400.0 4.247 4.347 -2.31% 2.17% -2.17% 0.14% 2/13 1300.0 4.068 4.067 +0.03% 1.77% -1.44% 1.04% 3/13 1200.0 3.889 3.796 +2.45% 1.96% -0.46% 1.91% 4/13 1100.0 3.509 3.526 -0.48% 1.77% -0.47% 1.71% 5/13 1000.0 3.219 3.252 -1.02% 1.67% -0.56% 1.57% 6/13 900.0 2.906 2.969 -2.14% 1.74% -0.78% 1.56% 7/13 800.0 2.593 2.677 -3.14% 1.97% -1.08% 1.65% 8/13 700.0 2.213 2.373 -6.77% 2.92% -1.71% 2.37% 9/13 600.0 2.079 2.059 +0.95% 2.79% -1.44% 2.39% 10/13 500.0 1.654 1.734 -4.63% 3.00% -1.73% 2.45% 11/13 400.0 1.207 1.258 -4.03% 3.10% -1.92% 2.43% 12/13 300.0 0.715 0.752 -4.86% 3.27% -2.15% 2.46% 13/13
20161009T024320 18.99C 55.8% 101398Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.381 4.654 -5.87% 5.87% -5.87% 0.00% 1/13 1400.0 4.113 4.347 -5.39% 5.64% -5.63% 0.24% 2/13 1300.0 3.979 4.067 -2.17% 4.77% -4.48% 1.64% 3/13 1200.0 3.621 3.796 -4.62% 4.73% -4.51% 1.42% 4/13 1100.0 3.375 3.526 -4.29% 4.65% -4.47% 1.28% 5/13 1000.0 3.107 3.252 -4.45% 4.61% -4.46% 1.17% 6/13 900.0 2.839 2.969 -4.39% 4.58% -4.45% 1.08% 7/13 800.0 2.526 2.677 -5.64% 4.73% -4.60% 1.08% 8/13 700.0 2.235 2.373 -5.83% 4.86% -4.74% 1.09% 9/13 600.0 2.056 2.059 -0.13% 4.61% -4.28% 1.73% 10/13 500.0 1.721 1.734 -0.76% 4.40% -3.96% 1.93% 11/13 400.0 1.229 1.258 -2.25% 4.27% -3.82% 1.91% 12/13 300.0 0.715 0.752 -4.86% 4.32% -3.90% 1.86% 13/13
20161009T143902 18.96C 58.7% 101491Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.381 4.654 -5.87% 5.87% -5.87% 0.00% 1/13 1400.0 4.180 4.347 -3.85% 4.96% -4.86% 1.01% 2/13 1300.0 3.867 4.067 -4.92% 4.95% -4.88% 0.83% 3/13 1200.0 3.576 3.796 -5.79% 5.17% -5.11% 0.82% 4/13 1100.0 3.353 3.526 -4.92% 5.12% -5.07% 0.74% 5/13 1000.0 3.107 3.252 -4.45% 5.02% -4.97% 0.71% 6/13 900.0 2.794 2.969 -5.90% 5.15% -5.10% 0.73% 7/13 800.0 2.459 2.677 -8.15% 5.62% -5.48% 1.22% 8/13 700.0 2.168 2.373 -8.65% 6.03% -5.83% 1.52% 9/13 600.0 1.989 2.059 -3.39% 5.82% -5.59% 1.62% 10/13 500.0 1.609 1.734 -7.20% 5.96% -5.74% 1.61% 11/13 400.0 1.252 1.258 -0.47% 5.71% -5.30% 2.12% 12/13 300.0 0.738 0.752 -1.88% 5.51% -5.03% 2.23% 13/13
20161009T192023 18.77C 58.0% 101483Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.470 4.654 -3.95% 3.95% -3.95% 0.00% 1/13 1400.0 4.202 4.347 -3.33% 3.65% -3.64% 0.31% 2/13 1300.0 3.979 4.067 -2.17% 3.24% -3.15% 0.74% 3/13 1200.0 3.710 3.796 -2.26% 3.02% -2.93% 0.75% 4/13 1100.0 3.442 3.526 -2.39% 2.91% -2.82% 0.70% 5/13 1000.0 3.129 3.252 -3.77% 3.07% -2.98% 0.73% 6/13 900.0 2.816 2.969 -5.15% 3.44% -3.29% 1.02% 7/13 800.0 2.459 2.677 -8.15% 4.32% -3.89% 1.87% 8/13 700.0 2.146 2.373 -9.59% 5.18% -4.53% 2.51% 9/13 600.0 2.034 2.059 -1.22% 4.93% -4.20% 2.58% 10/13 500.0 1.654 1.734 -4.63% 4.90% -4.24% 2.46% 11/13 400.0 1.207 1.258 -4.03% 4.83% -4.22% 2.36% 12/13 300.0 0.715 0.752 -4.86% 4.84% -4.27% 2.27% 13/13
20161010T155249 18.26C 56.4% 101852Pa WM-2 orig 3mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.605 4.654 -1.07% 1.07% -1.07% 0.00% 1/13 1400.0 4.359 4.347 +0.26% 0.78% -0.40% 0.67% 2/13 1300.0 4.090 4.067 +0.58% 0.72% -0.07% 0.71% 3/13 1200.0 3.800 3.796 +0.09% 0.62% -0.03% 0.62% 4/13 1100.0 3.532 3.526 +0.15% 0.56% +0.00% 0.56% 5/13 1000.0 3.286 3.252 +1.05% 0.67% +0.18% 0.64% 6/13 900.0 2.950 2.969 -0.63% 0.66% +0.06% 0.66% 7/13 800.0 2.570 2.677 -3.97% 1.53% -0.44% 1.47% 8/13 700.0 2.213 2.373 -6.77% 2.68% -1.14% 2.42% 9/13 600.0 2.101 2.059 +2.04% 2.62% -0.83% 2.49% 10/13 500.0 1.721 1.734 -0.76% 2.51% -0.82% 2.37% 11/13 400.0 1.229 1.258 -2.25% 2.49% -0.94% 2.31% 12/13 300.0 0.760 0.752 +1.09% 2.41% -0.78% 2.28% 13/13
The 3 mm roughness plate was machined to have a 1 mm roughness. Note that only the formula scale factor changes, reflecting the difference in the plate cross-sectional area.
20170323T005623 14.16C 34.2% 102062Pa WM-2 orig 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.649 4.635 +0.31% 0.31% +0.31% 0.00% 1/13 1400.0 4.381 4.329 +1.20% 0.88% +0.76% 0.45% 2/13 1300.0 4.023 4.050 -0.65% 0.81% +0.29% 0.76% 3/13 1200.0 3.755 3.780 -0.67% 0.78% +0.05% 0.78% 4/13 1100.0 3.487 3.512 -0.70% 0.76% -0.10% 0.76% 5/13 1000.0 3.174 3.238 -1.98% 1.07% -0.42% 0.98% 6/13 900.0 2.906 2.957 -1.72% 1.18% -0.60% 1.02% 7/13 800.0 2.638 2.666 -1.05% 1.17% -0.66% 0.96% 8/13 700.0 2.235 2.364 -5.43% 2.12% -1.19% 1.75% 9/13 600.0 2.123 2.051 +3.56% 2.30% -0.71% 2.19% 10/13 500.0 1.743 1.727 +0.95% 2.21% -0.56% 2.14% 11/13 400.0 1.252 1.249 +0.22% 2.12% -0.50% 2.06% 12/13 300.0 0.760 0.745 +1.98% 2.11% -0.31% 2.09% 13/13
20170325T192516 12.94C 38.0% 102261Pa WM-2 orig 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.560 4.635 -1.62% 1.62% -1.62% 0.00% 1/13 1400.0 4.381 4.329 +1.20% 1.42% -0.21% 1.41% 2/13 1300.0 4.113 4.050 +1.55% 1.47% +0.38% 1.42% 3/13 1200.0 3.755 3.780 -0.67% 1.32% +0.12% 1.31% 4/13 1100.0 3.532 3.512 +0.57% 1.20% +0.21% 1.19% 5/13 1000.0 3.174 3.238 -1.98% 1.36% -0.16% 1.36% 6/13 900.0 2.906 2.957 -1.72% 1.42% -0.38% 1.37% 7/13 800.0 2.638 2.666 -1.05% 1.38% -0.46% 1.30% 8/13 700.0 2.280 2.364 -3.54% 1.76% -0.81% 1.56% 9/13 600.0 2.146 2.051 +4.65% 2.22% -0.26% 2.21% 10/13 500.0 1.743 1.727 +0.95% 2.14% -0.15% 2.13% 11/13 400.0 1.252 1.249 +0.22% 2.05% -0.12% 2.04% 12/13 300.0 0.760 0.745 +1.98% 2.04% +0.04% 2.04% 13/13
The plate was flipped over, causing the test surface to ride higher in the test chamber. The Bernoulli principle caused flow over the test surface to increase about 4%. The prediction traces are scaled by 1.04.
upward-facing
20170703T230727 20.77C 63.3% 102022Pa -90 WM-2 *1.0400 orig 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.783 4.820 -0.76% 0.76% -0.76% 0.00% 1/13 1400.0 4.470 4.502 -0.70% 0.73% -0.73% 0.03% 2/13 1300.0 4.202 4.212 -0.23% 0.61% -0.57% 0.24% 3/13 1200.0 3.934 3.932 +0.06% 0.53% -0.41% 0.34% 4/13 1100.0 3.666 3.652 +0.37% 0.50% -0.25% 0.44% 5/13 1000.0 3.398 3.368 +0.89% 0.59% -0.06% 0.58% 6/13 900.0 3.085 3.075 +0.31% 0.56% -0.01% 0.55% 7/13 800.0 2.727 2.772 -1.63% 0.78% -0.21% 0.75% 8/13 700.0 2.369 2.458 -3.61% 1.41% -0.59% 1.28% 9/13 600.0 2.190 2.133 +2.72% 1.59% -0.26% 1.57% 10/13 500.0 1.699 1.796 -5.42% 2.23% -0.73% 2.11% 11/13 400.0 1.252 1.331 -5.98% 2.74% -1.17% 2.48% 12/13 300.0 0.760 0.807 -5.88% 3.10% -1.53% 2.70% 13/13
plate at +84° angle (nearly downward-facing)
20170803T234501 20.68C 65.3% 104538Pa +84 84 WM-2 orig 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.560 4.635 -1.62% 1.62% -1.62% 0.00% 1/13 1400.0 4.292 4.329 -0.86% 1.30% -1.24% 0.38% 2/13 1300.0 4.113 4.050 +1.55% 1.39% -0.31% 1.35% 3/13 1200.0 3.845 3.780 +1.70% 1.47% +0.19% 1.46% 4/13 1100.0 3.532 3.512 +0.57% 1.34% +0.27% 1.31% 5/13 1000.0 3.263 3.238 +0.78% 1.26% +0.35% 1.21% 6/13 900.0 2.906 2.957 -1.72% 1.34% +0.06% 1.34% 7/13 800.0 2.593 2.666 -2.73% 1.58% -0.29% 1.55% 8/13 700.0 2.280 2.364 -3.54% 1.90% -0.65% 1.79% 9/13 600.0 2.146 2.051 +4.65% 2.33% -0.12% 2.32% 10/13 500.0 1.743 1.727 +0.95% 2.24% -0.02% 2.24% 11/13 400.0 1.296 1.249 +3.80% 2.41% +0.29% 2.39% 12/13 300.0 0.760 0.745 +1.98% 2.38% +0.42% 2.34% 13/13
vertical
20170805T185824 21.22C 65.5% 100899Pa 0 180 WM-2 orig 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.493 4.635 -3.06% 3.06% -3.06% 0.00% 1/13 1400.0 4.247 4.329 -1.90% 2.55% -2.48% 0.58% 2/13 1300.0 4.068 4.050 +0.45% 2.10% -1.50% 1.46% 3/13 1200.0 3.755 3.780 -0.67% 1.85% -1.29% 1.32% 4/13 1100.0 3.532 3.512 +0.57% 1.67% -0.92% 1.39% 5/13 1000.0 3.263 3.238 +0.78% 1.56% -0.64% 1.42% 6/13 900.0 2.995 2.957 +1.30% 1.52% -0.36% 1.48% 7/13 800.0 2.593 2.666 -2.73% 1.72% -0.66% 1.59% 8/13 700.0 2.280 2.364 -3.54% 2.01% -0.98% 1.75% 9/13 600.0 2.146 2.051 +4.65% 2.40% -0.41% 2.37% 10/13 500.0 1.743 1.727 +0.95% 2.31% -0.29% 2.29% 11/13 400.0 1.296 1.249 +3.80% 2.47% +0.05% 2.47% 12/13 300.0 0.872 0.745 +16.97% 5.27% +1.35% 5.09% 13/13
Skipping spoiled calibrations during cowling leak 2017-10-19 -- 2017-11-01
First measurements with the ABM-200 anemometer, using its mobile-app to average consecutive measurements. Note: the ABM-200 readings around 3.25 m/s are intermittently 0 so often that time-averaged readings are invalid.
Airspeeds slower than 2 m/s should be nearly proportional to the fan rotation rate. The ABM-200 readings are close to 1.125u−0.381 in this range, the blue trace in its graphs.
downward-facing
20171101 17.9C 55.5% 102090Pa ABM-200 repaired 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.206 4.212 -0.13% 0.13% -0.13% 0.00% 1/12 1400.0 4.003 3.982 +0.54% 0.39% +0.20% 0.33% 2/12 1300.0 3.805 3.762 +1.15% 0.74% +0.52% 0.52% 3/12 1200.0 3.541 3.540 +0.03% 0.64% +0.40% 0.50% 4/12 1000.0 3.043 3.066 -0.74% 0.66% +0.17% 0.64% 5/12 900.0 2.809 2.805 +0.15% 0.60% +0.17% 0.58% 6/12 800.0 2.489 2.526 -1.44% 0.78% -0.06% 0.78% 7/12 700.0 2.215 2.225 -0.48% 0.75% -0.12% 0.74% 8/12 600.0 1.849 1.904 -2.89% 1.19% -0.42% 1.12% 9/12 500.0 1.560 1.562 -0.15% 1.13% -0.40% 1.06% 10/12 400.0 1.250 1.200 +4.13% 1.65% +0.02% 1.65% 11/12 300.0 0.879 0.821 +7.00% 2.57% +0.60% 2.49% 12/12
20171102T002104 18.2C 54.5% 102090Pa 32s ABM-200 repaired 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.206 4.212 -0.13% 0.13% -0.13% 0.00% 1/12 1400.0 4.003 3.982 +0.54% 0.39% +0.20% 0.33% 2/12 1300.0 3.805 3.762 +1.15% 0.74% +0.52% 0.52% 3/12 1200.0 3.541 3.540 +0.03% 0.64% +0.40% 0.50% 4/12 1000.0 3.043 3.066 -0.74% 0.66% +0.17% 0.64% 5/12 900.0 2.809 2.805 +0.15% 0.60% +0.17% 0.58% 6/12 800.0 2.489 2.526 -1.44% 0.78% -0.06% 0.78% 7/12 700.0 2.215 2.225 -0.48% 0.75% -0.12% 0.74% 8/12 600.0 1.849 1.904 -2.89% 1.19% -0.42% 1.12% 9/12 500.0 1.560 1.562 -0.15% 1.13% -0.40% 1.06% 10/12 400.0 1.250 1.200 +4.13% 1.65% +0.02% 1.65% 11/12 300.0 0.879 0.821 +7.00% 2.57% +0.60% 2.49% 12/12
20171103T174111 18.4C 58.5% 100710Pa ABM-200 repaired 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.100 4.212 -2.66% 2.66% -2.66% 0.00% 1/12 1400.0 3.912 3.982 -1.76% 2.26% -2.21% 0.45% 2/12 1300.0 3.698 3.762 -1.68% 2.08% -2.04% 0.44% 3/12 1200.0 3.475 3.540 -1.84% 2.03% -1.99% 0.39% 4/12 1000.0 3.012 3.066 -1.73% 1.97% -1.94% 0.37% 5/12 900.0 2.744 2.805 -2.17% 2.00% -1.97% 0.35% 6/12 800.0 2.484 2.526 -1.64% 1.96% -1.93% 0.34% 7/12 700.0 2.200 2.225 -1.16% 1.88% -1.83% 0.41% 8/12 600.0 1.900 1.904 -0.22% 1.77% -1.65% 0.64% 9/12 500.0 1.590 1.562 +1.80% 1.77% -1.31% 1.20% 10/12 400.0 1.285 1.200 +7.09% 2.73% -0.54% 2.67% 11/12 300.0 0.879 0.821 +7.00% 3.30% +0.09% 3.30% 12/12
20171104 18.4C 58.5% 100710Pa ABM-200 repaired 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.172 4.212 -0.94% 0.94% -0.94% 0.00% 1/12 1400.0 3.981 3.982 -0.01% 0.67% -0.48% 0.47% 2/12 1300.0 3.759 3.762 -0.06% 0.55% -0.34% 0.43% 3/12 1200.0 3.532 3.540 -0.22% 0.49% -0.31% 0.37% 4/12 1000.0 3.048 3.066 -0.57% 0.50% -0.36% 0.35% 5/12 900.0 2.805 2.805 +0.01% 0.46% -0.30% 0.35% 6/12 800.0 2.522 2.526 -0.13% 0.43% -0.28% 0.33% 7/12 700.0 2.245 2.225 +0.89% 0.51% -0.13% 0.49% 8/12 600.0 1.928 1.904 +1.25% 0.64% +0.02% 0.64% 9/12 500.0 1.631 1.562 +4.40% 1.52% +0.46% 1.45% 10/12 400.0 1.267 1.200 +5.61% 2.23% +0.93% 2.02% 11/12 300.0 0.893 0.821 +8.71% 3.29% +1.58% 2.89% 12/12
20171107 17C 63.5% 101510Pa ABM-200 repaired 1mm r/min measure predict RE RMSRE bias scatter used 1100.0 3.322 3.309 +0.39% 0.39% +0.39% 0.00% 1/9 1000.0 3.071 3.066 +0.17% 0.30% +0.28% 0.11% 2/9 900.0 2.802 2.805 -0.12% 0.26% +0.15% 0.21% 3/9 800.0 2.525 2.526 -0.03% 0.22% +0.10% 0.20% 4/9 700.0 2.256 2.225 +1.35% 0.64% +0.35% 0.53% 5/9 600.0 1.976 1.904 +3.78% 1.65% +0.92% 1.37% 6/9 500.0 1.679 1.562 +7.49% 3.22% +1.86% 2.62% 7/9 400.0 1.341 1.200 +11.75% 5.13% +3.10% 4.09% 8/9 300.0 0.955 0.821 +16.28% 7.27% +4.56% 5.66% 9/9
2018-03 Moved to Waltham. The wind-tunnel was disassembled, then reassembled after the move. Height of the plate suspension changed, causing a change in the coefficients.
20180515T012642 15.50C 53.5% 100755Pa ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.156 4.001 +3.86% 3.86% +3.86% 0.00% 1/11 1400.0 3.926 3.793 +3.51% 3.69% +3.68% 0.17% 2/11 1300.0 3.684 3.592 +2.55% 3.35% +3.31% 0.55% 3/11 1200.0 3.450 3.389 +1.82% 3.04% +2.93% 0.80% 4/11 1000.0 2.954 2.948 +0.21% 2.72% +2.39% 1.30% 5/11 900.0 2.703 2.704 -0.02% 2.49% +1.99% 1.49% 6/11 800.0 2.449 2.440 +0.40% 2.31% +1.76% 1.49% 7/11 700.0 2.146 2.154 -0.39% 2.16% +1.49% 1.56% 8/11 600.0 1.859 1.846 +0.67% 2.05% +1.40% 1.50% 9/11 500.0 1.591 1.516 +4.91% 2.49% +1.75% 1.77% 10/11 400.0 1.230 1.166 +5.51% 2.90% +2.09% 2.00% 11/11
2018-05-25 anemometer shifted 4.5 cm right.
20180525T012234 15.13C 60.2% 101428Pa shifted-right ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.150 4.001 +3.72% 3.72% +3.72% 0.00% 1/11 1400.0 3.927 3.793 +3.52% 3.62% +3.62% 0.10% 2/11 1300.0 3.686 3.592 +2.61% 3.32% +3.28% 0.49% 3/11 1200.0 3.498 3.389 +3.23% 3.30% +3.27% 0.42% 4/11 1000.0 3.069 2.948 +4.11% 3.48% +3.44% 0.51% 5/11 900.0 2.817 2.704 +4.20% 3.61% +3.57% 0.54% 6/11 800.0 2.485 2.440 +1.85% 3.41% +3.32% 0.78% 7/11 700.0 2.259 2.154 +4.86% 3.62% +3.51% 0.89% 8/11 600.0 1.933 1.846 +4.70% 3.76% +3.64% 0.92% 9/11 500.0 1.623 1.516 +7.03% 4.20% +3.98% 1.34% 10/11 400.0 1.241 1.166 +6.41% 4.45% +4.20% 1.45% 11/11
2018-05-29 anemometer centered.
20180529T002443 16.09C 62.8% 101202Pa ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 3.941 4.001 -1.52% 1.52% -1.52% 0.00% 1/11 1400.0 3.795 3.793 +0.04% 1.08% -0.74% 0.78% 2/11 1300.0 3.507 3.592 -2.39% 1.63% -1.29% 1.00% 3/11 1200.0 3.341 3.389 -1.40% 1.58% -1.32% 0.87% 4/11 1000.0 2.919 2.948 -0.99% 1.48% -1.25% 0.79% 5/11 900.0 2.583 2.704 -4.48% 2.27% -1.79% 1.40% 6/11 800.0 2.379 2.440 -2.48% 2.30% -1.89% 1.32% 7/11 700.0 2.192 2.154 +1.77% 2.24% -1.43% 1.73% 8/11 600.0 1.791 1.846 -3.01% 2.34% -1.61% 1.70% 9/11 500.0 1.494 1.516 -1.48% 2.27% -1.59% 1.62% 10/11 400.0 1.163 1.166 -0.22% 2.16% -1.47% 1.59% 11/11
20180603T200030 16.67C 66.3% 101366Pa ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.023 4.001 +0.55% 0.55% +0.55% 0.00% 1/11 1400.0 3.782 3.793 -0.29% 0.44% +0.13% 0.42% 2/11 1300.0 3.605 3.592 +0.36% 0.41% +0.20% 0.36% 3/11 1200.0 3.380 3.389 -0.26% 0.38% +0.09% 0.37% 4/11 1000.0 2.913 2.948 -1.18% 0.63% -0.16% 0.61% 5/11 900.0 2.689 2.704 -0.53% 0.61% -0.23% 0.57% 6/11 800.0 2.418 2.440 -0.88% 0.66% -0.32% 0.57% 7/11 700.0 2.105 2.154 -2.29% 1.02% -0.57% 0.85% 8/11 600.0 1.844 1.846 -0.14% 0.96% -0.52% 0.81% 9/11 500.0 1.521 1.516 +0.33% 0.92% -0.43% 0.81% 10/11 400.0 1.165 1.166 -0.09% 0.87% -0.40% 0.78% 11/11
20180607T000754 15.58C 65.0% 100970Pa ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.029 4.001 +0.68% 0.68% +0.68% 0.00% 1/11 1400.0 3.761 3.793 -0.85% 0.77% -0.08% 0.77% 2/11 1300.0 3.556 3.592 -1.01% 0.86% -0.39% 0.76% 3/11 1200.0 3.327 3.389 -1.82% 1.18% -0.75% 0.90% 4/11 1000.0 2.949 2.948 +0.02% 1.05% -0.60% 0.87% 5/11 900.0 2.698 2.704 -0.20% 0.96% -0.53% 0.80% 6/11 800.0 2.434 2.440 -0.23% 0.90% -0.49% 0.75% 7/11 700.0 2.137 2.154 -0.77% 0.88% -0.52% 0.71% 8/11 600.0 1.820 1.846 -1.42% 0.96% -0.62% 0.73% 9/11 500.0 1.555 1.516 +2.54% 1.21% -0.31% 1.17% 10/11 400.0 1.167 1.166 +0.09% 1.16% -0.27% 1.12% 11/11
20180608T235530 15.24C 63.3% 101467Pa ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 3.963 4.001 -0.95% 0.95% -0.95% 0.00% 1/11 1400.0 3.791 3.793 -0.05% 0.67% -0.50% 0.45% 2/11 1300.0 3.570 3.592 -0.62% 0.65% -0.54% 0.37% 3/11 1200.0 3.363 3.389 -0.75% 0.68% -0.59% 0.34% 4/11 1000.0 2.912 2.948 -1.21% 0.82% -0.72% 0.39% 5/11 900.0 2.652 2.704 -1.92% 1.08% -0.92% 0.57% 6/11 800.0 2.393 2.440 -1.90% 1.23% -1.06% 0.63% 7/11 700.0 2.145 2.154 -0.43% 1.16% -0.98% 0.63% 8/11 600.0 1.881 1.846 +1.86% 1.26% -0.66% 1.07% 9/11 500.0 1.562 1.516 +3.01% 1.53% -0.29% 1.50% 10/11 400.0 1.203 1.166 +3.18% 1.74% +0.02% 1.74% 11/11
2022-05-22 rebuilt fan cowling
2022-06-14 moved tunnel to larger room
20220617T204146 21.02C 64.5% 100340Pa ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 3.977 4.001 -0.62% 0.62% -0.62% 0.00% 1/11 1400.0 3.822 3.793 +0.75% 0.69% +0.07% 0.68% 2/11 1300.0 3.631 3.592 +1.07% 0.84% +0.40% 0.73% 3/11 1200.0 3.410 3.389 +0.65% 0.79% +0.46% 0.64% 4/11 1000.0 2.966 2.948 +0.62% 0.76% +0.49% 0.58% 5/11 900.0 2.758 2.704 +2.02% 1.08% +0.75% 0.77% 6/11 800.0 2.429 2.440 -0.43% 1.01% +0.58% 0.83% 7/11 700.0 2.161 2.154 +0.34% 0.95% +0.55% 0.78% 8/11 600.0 1.837 1.846 -0.50% 0.91% +0.43% 0.80% 9/11 500.0 1.460 1.516 -3.74% 1.47% +0.02% 1.47% 10/11 400.0 1.180 1.166 +1.25% 1.45% +0.13% 1.44% 11/11
20220625T174850 20.61C 65.7% 100874Pa ABM-200 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.001 4.001 -0.00% 0.00% -0.00% 0.00% 1/13 1400.0 3.777 3.793 -0.44% 0.31% -0.22% 0.22% 2/13 1300.0 3.571 3.592 -0.61% 0.43% -0.35% 0.25% 3/13 1200.0 3.340 3.389 -1.42% 0.80% -0.62% 0.51% 4/13 1100.0 3.159 3.175 -0.51% 0.75% -0.59% 0.46% 5/13 1000.0 2.881 2.948 -2.26% 1.15% -0.87% 0.75% 6/13 900.0 2.626 2.704 -2.86% 1.52% -1.16% 0.98% 7/13 800.0 2.363 2.440 -3.12% 1.80% -1.40% 1.13% 8/13 700.0 2.090 2.154 -2.99% 1.97% -1.58% 1.17% 9/13 600.0 1.836 1.846 -0.56% 1.87% -1.48% 1.16% 10/13 500.0 1.506 1.516 -0.67% 1.80% -1.40% 1.13% 11/13 450.0 1.306 1.344 -2.83% 1.91% -1.52% 1.15% 12/13 400.0 1.082 1.166 -7.19% 2.71% -1.96% 1.87% 13/13
2023-05-23 Before realizing that the plate was not aligned with the test chamber, concern about possible ABM-200 bearing wear motivated facing the anemometer toward the back of the chamber. Had the ABM-200 app "source" control been changed from "exhaust" to "supply", the blue trace would have been the same; instead, the blue traces are the same when u<1.1725 m/s, but uses the theoretical formula when u>1.1725 m/s. To indicate this, ABM-back replaces ABM-200 in the annotations.
2023-05-23 new diffuser
measurements with *1.0712 were made in front of plate; otherwise, the anemometer was under the leading edge of the plate.
20230523T144124 18.5C 52.8% 101651Pa ABM-back *1.0712 diffuser r/min measure predict RE RMSRE bias scatter used 1399.6 3.795 3.903 -2.76% 2.76% -2.76% 0.00% 1/8 1300.5 3.627 3.658 -0.85% 2.04% -1.81% 0.95% 2/8 1199.7 3.411 3.417 -0.19% 1.67% -1.27% 1.09% 3/8 1100.4 3.076 3.179 -3.25% 2.18% -1.76% 1.28% 4/8 1000.0 2.855 2.920 -2.22% 2.19% -1.85% 1.16% 5/8 900.1 2.573 2.636 -2.40% 2.22% -1.94% 1.07% 6/8 800.0 2.309 2.341 -1.36% 2.12% -1.86% 1.02% 7/8 699.7 2.024 2.034 -0.47% 1.99% -1.69% 1.05% 8/8
20230525T134249 18.2C 55.2% 100757Pa ABM-back diffuser r/min measure predict RE RMSRE bias scatter used 1399.9 3.718 3.644 +2.03% 2.03% +2.03% 0.00% 1/8 1300.3 3.568 3.415 +4.48% 3.48% +3.26% 1.23% 2/8 1200.2 3.201 3.191 +0.32% 2.85% +2.28% 1.71% 3/8 1099.8 2.937 2.956 -0.65% 2.49% +1.55% 1.95% 4/8 1000.2 2.754 2.701 +1.99% 2.40% +1.63% 1.75% 5/8 900.1 2.473 2.436 +1.54% 2.27% +1.62% 1.60% 6/8 799.6 2.242 2.159 +3.83% 2.55% +1.93% 1.67% 7/8 700.1 1.978 1.875 +5.53% 3.09% +2.38% 1.96% 8/8
20230526T022911 18.2C 54.6% 100998Pa ABM-back diffuser r/min measure predict RE RMSRE bias scatter used 1400.1 3.680 3.645 +0.98% 0.98% +0.98% 0.00% 1/8 1300.1 3.611 3.414 +5.78% 4.14% +3.38% 2.40% 2/8 1200.2 3.308 3.191 +3.67% 3.99% +3.48% 1.96% 3/8 1100.4 3.076 2.958 +3.99% 3.99% +3.60% 1.71% 4/8 999.9 2.835 2.700 +5.01% 4.21% +3.89% 1.63% 5/8 900.3 2.561 2.436 +5.12% 4.38% +4.09% 1.56% 6/8 800.0 2.259 2.160 +4.57% 4.41% +4.16% 1.45% 7/8 699.9 2.013 1.874 +7.43% 4.89% +4.57% 1.74% 8/8
2023-06-01 Realigned plate in tunnel
20230601T163354 19.2C 58.6% 100626Pa ABM-back *1.0712 diffuser r/min measure predict RE RMSRE bias scatter used 1400.0 3.812 3.904 -2.37% 2.37% -2.37% 0.00% 1/8 1300.0 3.585 3.657 -1.97% 2.18% -2.17% 0.20% 2/8 1199.8 3.373 3.417 -1.30% 1.93% -1.88% 0.44% 3/8 1098.2 3.144 3.174 -0.96% 1.74% -1.65% 0.55% 4/8 999.0 2.865 2.917 -1.79% 1.75% -1.68% 0.50% 5/8 900.0 2.623 2.636 -0.48% 1.61% -1.48% 0.64% 6/8 798.5 2.387 2.337 +2.15% 1.70% -0.96% 1.40% 7/8 700.2 2.095 2.036 +2.94% 1.90% -0.47% 1.84% 8/8
20230601T195131 19.4C 59.7% 100413Pa ABM-back diffuser r/min measure predict RE RMSRE bias scatter used 1398.1 3.666 3.640 +0.72% 0.72% +0.72% 0.00% 1/8 1299.3 3.499 3.412 +2.53% 1.86% +1.63% 0.90% 2/8 1199.7 3.302 3.190 +3.51% 2.53% +2.26% 1.15% 3/8 1098.2 3.064 2.952 +3.79% 2.90% +2.64% 1.20% 4/8 998.9 2.841 2.697 +5.33% 3.52% +3.18% 1.52% 5/8 900.0 2.520 2.435 +3.47% 3.51% +3.23% 1.39% 6/8 800.0 2.282 2.160 +5.63% 3.89% +3.57% 1.54% 7/8 700.1 1.961 1.875 +4.63% 3.99% +3.70% 1.48% 8/8
20230602T012246 19.1C 61.3% 100390Pa ABM-back diffuser r/min measure predict RE RMSRE bias scatter used 1399.7 3.636 3.644 -0.22% 0.22% -0.22% 0.00% 1/7 1299.8 3.465 3.413 +1.50% 1.07% +0.64% 0.86% 2/7 1100.4 2.990 2.958 +1.07% 1.07% +0.78% 0.73% 3/7 1000.0 2.756 2.700 +2.08% 1.39% +1.11% 0.84% 4/7 900.0 2.507 2.435 +2.97% 1.82% +1.48% 1.06% 5/7 797.9 2.234 2.154 +3.68% 2.24% +1.85% 1.27% 6/7 699.3 1.951 1.872 +4.22% 2.62% +2.19% 1.44% 7/7
20230621T235359 19.2C 66.7% 101416Pa ABM-back diffuser r/min measure predict RE RMSRE bias scatter used 1399.2 3.628 3.642 -0.39% 0.39% -0.39% 0.00% 1/7 1300.9 3.436 3.416 +0.59% 0.50% +0.10% 0.49% 2/7 1097.7 2.987 2.951 +1.22% 0.81% +0.47% 0.66% 3/7 1001.5 2.754 2.704 +1.84% 1.16% +0.81% 0.83% 4/7 899.8 2.538 2.435 +4.24% 2.16% +1.50% 1.56% 5/7 798.5 2.273 2.156 +5.44% 2.97% +2.16% 2.04% 6/7 699.8 1.942 1.874 +3.62% 3.07% +2.36% 1.96% 7/7
2023-06-24 corrected w > 1200 r/min undercounting; the blue trace no longer curves upward.
(new) second ABM-200 anemometer
20230624T213043 20.1C 71.5% 99759Pa ABM-200 *0.9335 true rpm r/min measure predict RE RMSRE bias scatter used 1294.0 3.129 3.114 +0.47% 0.47% +0.47% 0.00% 1/8 1199.7 2.997 2.923 +2.53% 1.82% +1.50% 1.03% 2/8 1097.9 2.713 2.704 +0.31% 1.50% +1.10% 1.01% 3/8 999.5 2.529 2.480 +1.96% 1.62% +1.32% 0.95% 4/8 903.1 2.284 2.249 +1.57% 1.61% +1.37% 0.86% 5/8 799.9 2.031 1.988 +2.20% 1.72% +1.50% 0.84% 6/8 701.0 1.775 1.726 +2.85% 1.93% +1.70% 0.91% 7/8 599.8 1.503 1.446 +3.92% 2.27% +1.97% 1.13% 8/8
20230624T234734 20.3C 72.6% 99773Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1293.9 3.337 3.363 -0.77% 0.77% -0.77% 0.00% 1/8 1200.1 3.203 3.160 +1.39% 1.12% +0.31% 1.08% 2/8 1098.8 2.962 2.926 +1.22% 1.16% +0.61% 0.98% 3/8 1002.0 2.703 2.690 +0.45% 1.03% +0.57% 0.85% 4/8 900.1 2.436 2.428 +0.34% 0.93% +0.53% 0.77% 5/8 800.1 2.154 2.157 -0.15% 0.85% +0.41% 0.75% 6/8 701.3 1.871 1.877 -0.28% 0.80% +0.32% 0.73% 7/8 600.1 1.627 1.577 +3.15% 1.34% +0.67% 1.16% 8/8
20230625T003510 20.3C 72.4% 99775Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1296.5 3.356 3.368 -0.36% 0.36% -0.36% 0.00% 1/8 1198.1 3.173 3.155 +0.57% 0.48% +0.10% 0.46% 2/8 1098.5 2.932 2.926 +0.21% 0.41% +0.14% 0.38% 3/8 1000.0 2.707 2.685 +0.81% 0.54% +0.31% 0.44% 4/8 900.0 2.435 2.428 +0.31% 0.50% +0.31% 0.39% 5/8 800.0 2.200 2.157 +1.98% 0.93% +0.59% 0.72% 6/8 701.1 1.915 1.876 +2.06% 1.16% +0.80% 0.84% 7/8 600.0 1.621 1.577 +2.78% 1.46% +1.04% 1.03% 8/8
2023-07-01 no diffuser; same as new diffuser!
20230701T212507 19.4C 75.9% 100438Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1499.7 3.724 3.769 -1.20% 1.20% -1.20% 0.00% 1/10 1399.6 3.572 3.578 -0.17% 0.86% -0.69% 0.52% 2/10 1301.6 3.320 3.379 -1.76% 1.23% -1.04% 0.66% 3/10 1203.6 3.138 3.167 -0.93% 1.16% -1.01% 0.57% 4/10 1098.6 2.988 2.926 +2.12% 1.41% -0.39% 1.36% 5/10 1000.1 2.748 2.686 +2.31% 1.60% +0.06% 1.60% 6/10 900.1 2.500 2.428 +2.95% 1.85% +0.48% 1.79% 7/10 800.0 2.167 2.157 +0.45% 1.74% +0.47% 1.67% 8/10 701.2 1.931 1.876 +2.91% 1.91% +0.74% 1.75% 9/10 600.1 1.541 1.577 -2.26% 1.94% +0.44% 1.89% 10/10
with new diffuser
20230702T142307 20.3C 74.6% 100277Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1486.0 3.723 3.744 -0.55% 0.55% -0.55% 0.00% 1/10 1400.0 3.685 3.579 +2.95% 2.12% +1.20% 1.75% 2/10 1299.4 3.424 3.375 +1.48% 1.93% +1.29% 1.43% 3/10 1199.8 3.146 3.159 -0.42% 1.68% +0.86% 1.45% 4/10 1098.1 2.905 2.925 -0.66% 1.53% +0.56% 1.43% 5/10 1000.7 2.643 2.687 -1.66% 1.56% +0.19% 1.54% 6/10 899.4 2.347 2.426 -3.27% 1.90% -0.31% 1.87% 7/10 799.4 2.101 2.155 -2.51% 1.98% -0.58% 1.90% 8/10 701.1 1.831 1.876 -2.41% 2.04% -0.78% 1.88% 9/10 599.9 1.545 1.576 -1.97% 2.03% -0.90% 1.82% 10/10
20230705T234754 19.0C 76.4% 100257Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1300.3 3.364 3.376 -0.35% 0.35% -0.35% 0.00% 1/10 1198.8 3.159 3.157 +0.08% 0.26% -0.14% 0.22% 2/10 1098.1 2.945 2.925 +0.69% 0.45% +0.14% 0.43% 3/10 1000.3 2.681 2.686 -0.18% 0.40% +0.06% 0.40% 4/10 900.1 2.423 2.428 -0.20% 0.37% +0.01% 0.37% 5/10 800.0 2.174 2.157 +0.78% 0.46% +0.14% 0.44% 6/10 700.7 1.867 1.875 -0.43% 0.46% +0.05% 0.46% 7/10 599.9 1.535 1.576 -2.65% 1.03% -0.28% 0.99% 8/10 500.0 1.307 1.269 +2.98% 1.39% +0.08% 1.39% 9/10 400.2 0.869 0.953 -8.76% 3.07% -0.80% 2.96% 10/10
Improvement of the PLL software reduced fan (hence airspeed) variability at all speeds. Reduced variability enabled more accurate measurement over the 30 s averaging period of the ABM-200.
The remaining measurements were taken with the anemometer consistently 30 mm behind the center of the leading edge of the plate. ABM-200 measurements were captured after the fan PLL stabilized at each speed.
The ABM-200 readings differ slighly depending on whether the front of the anemometer is facing into the wind or away from it. This direction is not sensed by the ABM-200; the direction is set manually in the mobile-app.
Friction decreasing with wear makes the (worn) old ABM-200 readings higher than the new ABM-200 at the same airspeed. The front versus back bearing wear differs; the earlier concern about bearing wear was warranted.
old ABM-200 facing back
20230708T200218 19.7C 70.2% 99916Pa ABM-back true rpm r/min measure predict RE RMSRE bias scatter used 1432.2 3.900 3.576 +9.06% 1/11 1400.1 3.798 3.520 +7.88% 1/11 1298.8 3.470 3.337 +3.99% 1/11 1098.0 2.963 2.924 +1.31% 1.31% +1.31% 0.00% 1/11 999.6 2.712 2.684 +1.04% 1.18% +1.17% 0.13% 2/11 899.6 2.461 2.427 +1.40% 1.26% +1.25% 0.15% 3/11 799.7 2.179 2.156 +1.06% 1.21% +1.20% 0.16% 4/11 701.2 1.947 1.876 +3.75% 1.99% +1.71% 1.03% 5/11 599.9 1.658 1.576 +5.18% 2.79% +2.29% 1.60% 6/11 499.8 1.266 1.269 -0.17% 2.59% +1.94% 1.71% 7/11 400.0 0.930 0.952 -2.29% 2.55% +1.41% 2.13% 8/11
old ABM-200 facing front
20230708T202729 19.4C 73.7% 99916Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1429.8 3.784 3.637 +4.03% 4.03% +4.03% 0.00% 1/10 1399.7 3.672 3.579 +2.62% 3.40% +3.32% 0.70% 2/10 1298.9 3.470 3.374 +2.86% 3.23% +3.17% 0.61% 3/10 1097.3 2.974 2.923 +1.76% 2.93% +2.82% 0.81% 4/10 999.4 2.855 2.684 +6.37% 3.87% +3.53% 1.60% 5/10 899.8 2.561 2.427 +5.50% 4.19% +3.86% 1.63% 6/10 799.5 2.313 2.155 +7.30% 4.76% +4.35% 1.93% 7/10 701.2 2.102 1.876 +12.03% 6.16% +5.31% 3.12% 8/10 600.1 1.781 1.577 +12.91% 7.23% +6.15% 3.79% 9/10 500.1 1.409 1.270 +10.96% 7.68% +6.63% 3.87% 10/10
new ABM-200 facing back
20230708T204822 19.5C 79.0% 99914Pa ABM-back true rpm r/min measure predict RE RMSRE bias scatter used 1432.2 3.587 3.576 +0.33% 0.33% +0.33% 0.00% 1/12 1399.0 3.528 3.518 +0.28% 0.30% +0.30% 0.03% 2/12 1299.9 3.351 3.339 +0.36% 0.32% +0.32% 0.03% 3/12 1200.2 3.118 3.147 -0.94% 0.55% +0.00% 0.55% 4/12 1098.3 2.879 2.925 -1.57% 0.86% -0.31% 0.80% 5/12 999.8 2.645 2.685 -1.48% 0.99% -0.50% 0.85% 6/12 900.1 2.430 2.428 +0.09% 0.91% -0.42% 0.81% 7/12 799.9 2.159 2.157 +0.11% 0.86% -0.35% 0.78% 8/12 701.1 1.888 1.876 +0.62% 0.83% -0.25% 0.80% 9/12 600.1 1.629 1.577 +3.28% 1.30% +0.11% 1.30% 10/12 499.8 1.272 1.269 +0.27% 1.25% +0.12% 1.24% 11/12 400.2 0.943 0.953 -0.97% 1.22% +0.03% 1.22% 12/12
new ABM-200 facing front
20230708T211043 19.8C 81.1% 99902Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1433.8 3.657 3.645 +0.34% 0.34% +0.34% 0.00% 1/12 1398.8 3.581 3.577 +0.13% 0.25% +0.23% 0.10% 2/12 1300.2 3.386 3.376 +0.30% 0.27% +0.25% 0.09% 3/12 1200.2 3.146 3.160 -0.45% 0.32% +0.08% 0.31% 4/12 1098.3 2.887 2.925 -1.29% 0.65% -0.19% 0.62% 5/12 999.8 2.665 2.685 -0.72% 0.66% -0.28% 0.60% 6/12 899.9 2.392 2.428 -1.48% 0.83% -0.45% 0.69% 7/12 800.0 2.135 2.157 -1.01% 0.85% -0.52% 0.67% 8/12 701.2 1.889 1.876 +0.66% 0.83% -0.39% 0.74% 9/12 600.0 1.587 1.577 +0.69% 0.82% -0.28% 0.77% 10/12 500.0 1.272 1.269 +0.18% 0.78% -0.24% 0.74% 11/12 399.9 0.982 0.952 +3.19% 1.19% +0.04% 1.19% 12/12
new ABM-200 facing back in supply mode
20230714T184805 20.5C 76.5% 100307Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1438.9 3.642 3.655 -0.34% 0.34% -0.34% 0.00% 1/12 1399.6 3.550 3.578 -0.79% 0.61% -0.57% 0.23% 2/12 1300.4 3.350 3.377 -0.80% 0.68% -0.64% 0.22% 3/12 1200.0 3.128 3.159 -0.98% 0.77% -0.73% 0.24% 4/12 1098.5 2.885 2.926 -1.37% 0.92% -0.86% 0.34% 5/12 1000.3 2.664 2.686 -0.83% 0.90% -0.85% 0.31% 6/12 900.0 2.434 2.428 +0.27% 0.84% -0.69% 0.48% 7/12 800.2 2.187 2.157 +1.39% 0.93% -0.43% 0.82% 8/12 701.5 1.932 1.877 +2.94% 1.31% -0.06% 1.31% 9/12 600.0 1.600 1.577 +1.49% 1.33% +0.10% 1.33% 10/12 499.8 1.329 1.269 +4.75% 1.92% +0.52% 1.84% 11/12 400.1 0.997 0.952 +4.72% 2.28% +0.87% 2.11% 12/12
Disassembled the old ABM-200 and sprayed graphite powder into its bearings.
old ABM-200 front-facing in exhaust mode
20230716T221238 20.5C 83.8% 99861Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1399.8 3.824 3.579 +6.85% 6.85% +6.85% 0.00% 1/11 1300.0 3.699 3.376 +9.57% 8.32% +8.21% 1.36% 2/11 1199.9 3.365 3.159 +6.53% 7.77% +7.65% 1.36% 3/11 1097.6 3.140 2.924 +7.42% 7.68% +7.59% 1.18% 4/11 999.7 2.939 2.685 +9.47% 8.07% +7.97% 1.30% 5/11 899.5 2.648 2.427 +9.13% 8.26% +8.16% 1.26% 6/11 799.5 2.412 2.155 +11.92% 8.88% +8.70% 1.76% 7/11 701.0 2.121 1.876 +13.07% 9.50% +9.24% 2.19% 8/11 599.6 1.828 1.575 +16.05% 10.43% +10.00% 2.97% 9/11 499.8 1.495 1.269 +17.85% 11.39% +10.79% 3.67% 10/11 399.9 1.148 0.952 +20.64% 12.52% +11.68% 4.51% 11/11
old ABM-200 back-facing in supply mode
20230716T234110 20.7C 81.4% 99858Pa ABM-200 true rpm r/min measure predict RE RMSRE bias scatter used 1400.0 3.766 3.579 +5.22% 5.22% +5.22% 0.00% 1/11 1299.7 3.576 3.375 +5.94% 5.59% +5.58% 0.36% 2/11 1200.5 3.338 3.160 +5.62% 5.60% +5.59% 0.30% 3/11 1097.6 3.102 2.924 +6.10% 5.73% +5.72% 0.34% 4/11 999.9 2.891 2.685 +7.65% 6.16% +6.11% 0.83% 5/11 900.1 2.653 2.428 +9.25% 6.78% +6.63% 1.40% 6/11 799.8 2.373 2.156 +10.07% 7.34% +7.12% 1.76% 7/11 701.3 2.117 1.877 +12.82% 8.23% +7.83% 2.51% 8/11 599.8 1.849 1.576 +17.29% 9.66% +8.89% 3.80% 9/11 499.9 1.529 1.269 +20.50% 11.23% +10.05% 5.01% 10/11 400.0 1.162 0.952 +22.10% 12.61% +11.14% 5.90% 11/11
The old ABM-200 with graphite reads a fixed velocity greater than the predicted trace, consistent with a reduction in its dry friction coefficient. The smoother measured curve is consistent with a reduction of play in the bearings.
Five years after its previous use, the WM-2 reported excessive speeds at fan rotation rates larger than 900 r/min. The following WM-2 measurements are averages of eight or more non-consecutive readings per fan speed.
20220626T231300 20.61C 65.7% 100874Pa WM-2 moved 1mm r/min measure predict RE RMSRE bias scatter used 1500.0 4.320 3.895 +10.89% 10.89% +10.89% 0.00% 1/13 1400.0 4.034 3.710 +8.71% 9.86% +9.80% 1.09% 2/13 1300.0 3.845 3.532 +8.85% 9.54% +9.48% 1.00% 3/13 1200.0 3.587 3.351 +7.06% 8.98% +8.88% 1.36% 4/13 1100.0 3.327 3.161 +5.26% 8.37% +8.15% 1.89% 5/13 1000.0 3.042 2.959 +2.81% 7.73% +7.26% 2.64% 6/13 900.0 2.725 2.742 -0.63% 7.16% +6.13% 3.69% 7/13 800.0 2.472 2.507 -1.41% 6.71% +5.19% 4.26% 8/13 700.0 2.171 2.253 -3.66% 6.45% +4.21% 4.88% 9/13 600.0 1.949 1.980 -1.55% 6.13% +3.63% 4.94% 10/13 500.0 1.582 1.681 -5.91% 6.11% +2.76% 5.45% 11/13 400.0 1.168 1.221 -4.35% 5.99% +2.17% 5.58% 12/13 300.0 0.657 0.736 -10.76% 6.48% +1.18% 6.37% 13/13
20230622 19.2C 66.7% 101416Pa WM-2 diffuser r/min measure predict RE RMSRE bias scatter used 1400.0 4.000 3.644 +9.75% 9.75% +9.75% 0.00% 1/11 1300.0 3.707 3.414 +8.59% 9.19% +9.17% 0.58% 2/11 1200.0 3.441 3.191 +7.84% 8.76% +8.73% 0.79% 3/11 1100.0 3.292 2.967 +10.96% 9.36% +9.29% 1.18% 4/11 1000.0 2.967 2.739 +8.32% 9.16% +9.09% 1.13% 5/11 900.0 2.676 2.503 +6.88% 8.82% +8.73% 1.32% 6/11 800.0 2.333 2.259 +3.28% 8.26% +7.95% 2.26% 7/11 700.0 2.050 2.005 +2.24% 7.77% +7.23% 2.84% 8/11 600.0 1.864 1.741 +7.11% 7.70% +7.22% 2.67% 9/11 500.0 1.430 1.357 +5.41% 7.50% +7.04% 2.59% 10/11 400.0 0.972 0.940 +3.36% 7.22% +6.71% 2.69% 11/11
20230709T172345 19.79C 79.1% 99880Pa WM-2 true rpm r/min measure predict RE RMSRE bias scatter used 1400.0 4.055 3.520 +15.20% 1/12 1300.0 3.714 3.339 +11.22% 1/12 1200.0 3.471 3.147 +10.30% 1/12 1100.0 3.201 2.942 +8.79% 1/12 1000.0 2.824 2.726 +3.62% 3.62% +3.62% 0.00% 1/12 900.0 2.583 2.497 +3.46% 3.54% +3.54% 0.08% 2/12 800.0 2.353 2.256 +4.29% 3.81% +3.79% 0.36% 3/12 700.0 2.145 2.003 +7.07% 4.83% +4.61% 1.45% 4/12 600.0 1.844 1.740 +5.97% 5.08% +4.88% 1.41% 5/12 500.0 1.419 1.357 +4.62% 5.01% +4.84% 1.29% 6/12 400.0 0.985 0.940 +4.77% 4.97% +4.83% 1.19% 7/12 300.0 0.558 0.513 +8.78% 5.59% +5.32% 1.72% 8/12
Unable to disassemble the WM-2, sprayed WD-40 into its bearings.
20230716T212354 20.06C 80.8% 99887Pa WM-2 true rpm r/min measure predict RE RMSRE bias scatter used 1400.0 3.880 3.520 +10.24% 1/11 1300.0 3.656 3.339 +9.49% 1/11 1200.0 3.404 3.147 +8.16% 1/11 1100.0 3.113 2.942 +5.79% 1/11 1000.0 2.826 2.726 +3.67% 1/11 900.0 2.550 2.497 +2.14% 2.14% +2.14% 0.00% 1/11 800.0 2.234 2.256 -0.97% 1.66% +0.58% 1.56% 2/11 700.0 2.113 2.003 +5.45% 3.43% +2.20% 2.62% 3/11 600.0 1.696 1.740 -2.53% 3.23% +1.02% 3.06% 4/11 500.0 1.278 1.357 -5.82% 3.89% -0.35% 3.87% 5/11 400.0 0.853 0.940 -9.28% 5.19% -1.84% 4.85% 6/11
After lubrication, the WM-2 returned to its previous behavior below 1000 r/min.
Lubricating with "Hetman synthetic classic piston lubricant 3":
20230717T195910 20.38C 80.6% 100134Pa WM-2 true rpm r/min measure predict RE RMSRE bias scatter used 1400.0 3.845 3.520 +9.23% 9.23% +9.23% 0.00% 1/11 1300.0 3.557 3.339 +6.51% 7.98% +7.87% 1.36% 2/11 1200.0 3.336 3.147 +6.02% 7.39% +7.25% 1.41% 3/11 1100.0 3.083 2.942 +4.78% 6.83% +6.63% 1.63% 4/11 1000.0 2.736 2.726 +0.39% 6.11% +5.38% 2.89% 5/11 900.0 2.446 2.497 -2.03% 5.64% +4.15% 3.82% 6/11 800.0 2.148 2.256 -4.80% 5.53% +2.87% 4.72% 7/11 700.0 2.027 2.003 +1.17% 5.19% +2.66% 4.45% 8/11 600.0 1.635 1.740 -6.04% 5.29% +1.69% 5.01% 9/11 500.0 1.256 1.357 -7.41% 5.54% +0.78% 5.48% 10/11 400.0 0.838 0.940 -10.90% 6.22% -0.28% 6.21% 11/11
Lubricating with "Hetman synthetic light slide lubricant 4" is little changed in the graph; but static friction is nearly 0.
20230717T202639 20.12C 74.8% 100157Pa WM-2 true rpm r/min measure predict RE RMSRE bias scatter used 1400.0 3.830 3.520 +8.80% 8.80% +8.80% 0.00% 1/11 1300.0 3.643 3.339 +9.09% 8.94% +8.94% 0.15% 2/11 1200.0 3.395 3.147 +7.89% 8.61% +8.59% 0.51% 3/11 1100.0 3.078 2.942 +4.60% 7.80% +7.60% 1.78% 4/11 1000.0 2.821 2.726 +3.51% 7.15% +6.78% 2.28% 5/11 900.0 2.368 2.497 -5.16% 6.86% +4.79% 4.91% 6/11 800.0 2.212 2.256 -1.96% 6.40% +3.82% 5.13% 7/11 700.0 2.133 2.003 +6.46% 6.40% +4.15% 4.87% 8/11 600.0 1.669 1.740 -4.07% 6.19% +3.24% 5.27% 9/11 500.0 1.308 1.357 -3.58% 5.98% +2.56% 5.40% 10/11 400.0 0.871 0.940 -7.32% 6.11% +1.66% 5.88% 11/11
Lubricating with 3-in-1 machine oil SAE-20 brings w>1000 near theory, but also reduces the dry friction region.
20230717T211056 20.48C 82.4% 100159Pa WM-2 true rpm r/min measure predict RE RMSRE bias scatter used 1400.0 3.677 3.520 +4.47% 4.47% +4.47% 0.00% 1/11 1300.0 3.412 3.339 +2.17% 3.51% +3.32% 1.15% 2/11 1200.0 3.167 3.147 +0.65% 2.89% +2.43% 1.57% 3/11 1100.0 2.845 2.942 -3.32% 3.00% +0.99% 2.83% 4/11 1000.0 2.569 2.726 -5.74% 3.72% -0.35% 3.70% 5/11 900.0 2.309 2.497 -7.50% 4.57% -1.55% 4.30% 6/11 800.0 2.065 2.256 -8.46% 5.30% -2.53% 4.66% 7/11 700.0 1.925 2.003 -3.90% 5.15% -2.70% 4.38% 8/11 600.0 1.530 1.740 -12.09% 6.31% -3.75% 5.08% 9/11 500.0 0.987 1.357 -27.21% 10.48% -6.09% 8.53% 10/11 400.0 0.710 0.940 -24.48% 12.42% -7.77% 9.70% 11/11
These experiments suggest that the WM-2 was originally lubricated with oil more viscous than lubricant 4 above. This original lubricant evaporated or denatured during the five years hiatus. Measurements with new lubrication indicate that the anemometers are in rough agreement.
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