Aerodynamic Heating Rate on Rocket

[physwil90]

I am currently helping in the design of a rocket and I am hoping to find a way to empirically calculate the heating rate on the fins. Note that these fins are located near the back of the rocket and that they are made of a fiberglass material. Also, the rocket maintains a speed of mach 1.5 for over 90s. I know that this heating rate cannot be expressed easily but any help would be great.

 

[IRstuff]

You can start by looking at what the aerodynamic heating will produce in terms of stagnation temperature:

http://en.wikipedia.org/wiki/Stagnation_temperature

TTFN

FAQ731-376

 

[btrueblood]

As IRstuff says, leading edges of the fins will see stagnation temperature.

 

[physwil90]

I am aware that the stagnation point is where the air has reached a velocity of 0 and thus will stagnate creating a higher point of aerodynamic heating. This situation would most likely occur for this rocket design, but I do not know if this equation is the only one I need.

The reason for this is because it only takes into account mach speed, free stream temperature at a particular altitude, and fluid properties (such as a recovery factor and ratio of specific heats, 1.4).

I still am under the impression that I need to look at the rate at which the temperature is changing rather an equation that gives a temperature value flat out.

 

[IRstuff]

You also need to treat this as a forced convection problem, but the reality is that you need to run a CFD-type analysis; I don't think that cranking equations will get you anywhere close to a plausible answer for design analysis.

TTFN

FAQ731-376