Mike:

Yes. top esc is only temporary as I am lazy too build a standoff at an angle to make the esc flush to bottom.


Open cowl will give higest flowrate but least will actually reach the surface of the motor as air stream will look for least resistant path. It is most beneficial to batt as the coolest air gets to batt. However, I'm not too concerned about the batt temp as I'm not pushing the batt too hard. 10min flight on 8000mah means the average current draw is 480ampmin/10min = 48amps or about 6C. It only gets warm which is also good for longevity of the pack.

As you put the baffle or louver, you are forcing the air to pass near the motor surface reducing the boundary layer thickness. You are reducing the Q (flowrate)

but improve the airflow near the motor. Combination of Fluid Dynamics and Heat Transfer at work.

The motor temp has been reduced but the esc temp has gone up before the esc relocation. To improve the system, concentric cylinder needs to be constructed around the motor so air does not escape to area on top and bottom where there is least restriction as is the case of current louver setup. Only expement will tell what the optimum gap between the ventury cylinder to motor can diameter should be.

I really need a separate cool air inlet from the motor air as it is already heated.