Thread: Discussion Propeller wind tunnel tests
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Old Jun 18, 2011, 07:52 PM
Martyn McKinney is offline
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The Thrust(Ct) and Power(Cp) coefficients are dimensionless coefficients which allow you to determine propeller thrust and absorbed power if you know the RPM, Pitch and Diameter and the air density (rho).

The coefficients in the TR-237 Technical Report are determined using Imperial units (Pounds Thrust - Horsepower).

http://hdl.handle.net/2060/19930091305

From the Advance graphs, the Thrust and Power may be determined for any airspeed.

On the Advance Curves, the X-axis may be considered airspeed.

The Y-axis gives the value of the coefficients for that airspeed.

On the X-axis the Pitch Speed (RPM X Pitch) is equal to an Advance equal to the Pitch/Diameter ratio.

A prop with a P/D ratio of 0.8 has a Pitch Speed (RPM X Pitch) with an Advance of 0.8.

The Zero Thrust Speed is equal to the Pitch Speed Advance + 0.2.

For a prop with a P/D ratio of 0.8, the Zero Thrust Speed occurs at an Advance of 1.0.
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Last edited by Martyn McKinney; Jun 19, 2011 at 08:43 AM.
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