Rocket drag coefficient

[turkkusuroket]

Hello guys;

I made analysis from ansys and found the cd=0.0037006761 but i don't know it's true

 

[Reinhard]

This number is too low by at magnitude. You can use RASAero to get a good estimation of the cd. If your number is very different from the RASAero result, something went wrong.

Reinhard

 

[JohnCoker]

I made analysis from ansys and found the cd=0.0037006761 but i don't know it's true

They are usually in the range 0.3 to 0.7 for model rocket.

 

[Buckeye]

Need more significant digits to know for sure...

 

[Chuck Rogers]

What's your reference area?

RASAero II, and other rocket software, use the max cross-sectional area of the body as the reference area. In fact in RASAero II the rocket reference area is put on all of the rocket aerodynamic data plots. (Something I think is a good practice.)

Your CD looks like the reference area is the surface area of the rocket. Use the max cross-sectional area of the rocket body as the reference area.


Charles E. (Chuck) Rogers
Rogers Aeroscience

 

[Buckeye]

You are attempting CFD analysis where dozens of things can go wrong for a newbie. Since the Cd is off by two orders of magnitude, and you are not even aware that is a problem, tells me you should brush up on the basics before going any further.

 

[turkkusuroket]

Can I use open rocket values? Do you think these values are realistic ?

 

[turkkusuroket]

max velocity 271 m/s