RCU Forums - View Single Post - How to Correct Measured Thrust for Density Altitude?
Old 09-12-2012, 09:48 AM
  #13  
rctech2k7
Senior Member
My Feedback: (1)
 
rctech2k7's Avatar
 
Join Date: May 2009
Location: Miami, FL
Posts: 377
Likes: 0
Received 0 Likes on 0 Posts
Default RE: How to Correct Measured Thrust for Density Altitude?

Let me try if I can help…

Considering Thrust (T)= mass flow rate * exhaust velocity

T = density * volume flow rate * velocity
T = density * A * (D/t) * velocity
T =density * A * velocity ^2

Consider test stand thrust T1 = density1 * A1 * velocity1 ^2
and test 2 thrust, T2 = density2 * A2 * velocity2 ^2

Same engine, Area A1 = A2 therefore

T2/T1 = density2 * velocity2^2/( density1 * velocity1^2)

T2 = T1 * [ density2 * velocity2^2/( density1 * velocity1^2)]

T2 = T1 * (density2/density1) * (velocity2/velocity1)^2

If T1 = T2 then

density1 * velocity1^2 = density2 * velocity2^2