formula to find cl and cd???

ganesh chakravarthi · April 11, 2015, 15:13

Hiii Everyone...,

i have created one turbine blade model by using coordinates and simulated in ANSYS-CFX Solver inorder to find lift and drag coefficients..for this i have used CEL Expressions...to validate this i have to do hand calculation..anyhow CFX Solver gives CL and CD values..but from CL and CD equation(from Aerodynamics)CL,CD,LIFT FORCE and DRAG FORCE are unknown parameters...directly we cant take the values from solver...right..

my question is how to find CL and CD through hand calculation????

Thank you...

Lionel · April 12, 2015, 07:24

hello,
you have the lift equation:
L = Cl * A * 0.5 * r * V^2
therefore by knowing the lift (L), density(r) and speed(V) from the solver and the blade area (A) from your geometry, you can calculate Cl.
In CFX-Post you can compute the force on a body from the quatitative tab

ganesh chakravarthi · April 12, 2015, 12:59

thank you..lionel...

i have used CEL Expressions to find CL and CD....I know that CFX Solver gives CL,CD,lift force and drag force..values also...

but directly i cant take simulation values...i need to validate analytically(HAND CALCULATION)

If we see CL and CD equation...CL,lift force and CD,drag force are unknown parameters....right...

April 11, 2015, 15:13	formula to find cl and cd???	#1
ganesh chakravarthi New Member ganesh chakravarthi Join Date: Apr 2014 Posts: 14 Rep Power: 12	Hiii Everyone..., i have created one turbine blade model by using coordinates and simulated in ANSYS-CFX Solver inorder to find lift and drag coefficients..for this i have used CEL Expressions...to validate this i have to do hand calculation..anyhow CFX Solver gives CL and CD values..but from CL and CD equation(from Aerodynamics)CL,CD,LIFT FORCE and DRAG FORCE are unknown parameters...directly we cant take the values from solver...right.. my question is how to find CL and CD through hand calculation???? Thank you...

April 12, 2015, 07:24		#2
Lionel New Member Join Date: Jun 2012 Posts: 5 Rep Power: 14	hello, you have the lift equation: L = Cl * A * 0.5 * r * V^2 therefore by knowing the lift (L), density(r) and speed(V) from the solver and the blade area (A) from your geometry, you can calculate Cl. In CFX-Post you can compute the force on a body from the quatitative tab

April 12, 2015, 12:59		#3
ganesh chakravarthi New Member ganesh chakravarthi Join Date: Apr 2014 Posts: 14 Rep Power: 12	thank you..lionel... i have used CEL Expressions to find CL and CD....I know that CFX Solver gives CL,CD,lift force and drag force..values also... but directly i cant take simulation values...i need to validate analytically(HAND CALCULATION) If we see CL and CD equation...CL,lift force and CD,drag force are unknown parameters....right...