I hadn't given much thought to the anemometer and was thinking of using a small cup type. But, I'm thinking the cup type may lead to some disrupted air. It may not be enough to create any problems or major data errors but I'm not sure where it should be placed for an accurate samplings. I'm using a handheld unit right now.
I did get the second jet fan running tonight, I'm laying on the floor of the tunnel taking windspeed readings with the handheld. I'm getting 18 mph readings from the center to the sides, close to the walls and ceiling it drops down to around 17. Sitting up in the tunnel the inlet readings are still very consistant.
I bolted the small Lenz turbine in place, using a stick with the handheld taped on I see 15 mph all around the turbine about 2 ft in front of the unit.
Well, I had to connect it to the test equipment before I would be happy and I wasn't comming in until I did. I have a feeling I'm going to be spending a large amount of time playing in the wind tunnel ! So, the initial test (play time) came in as follows:
1.37 amps at 14.4 volts in a 15 mph wind There is 68.58 watts total that can be collected in a 4 sq ft turbine (not taking in Betz). It made 19.72 watts charging the battery. I see a 28.7% overall machine. If you include the 3 watt loss through the alternator and the 1.92 watts lost in the rectifier then its making 24.64 watts or a blade efficiency of 36%. Pretty much what I had calculated before when I included my margin of error. So if you add Betz into the formula then the blade efficiency would be almost 60% of the maximum possible that can be extracted from that wind. ( 68.58 x .59 = 40.46 ) then ( 24.64 / 40.46 = 60.89%) or ( 19.72 / 40.46 = 48.7% overall of the total possible.
Still room for improvement!!
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