I am wondering if drag coefficients apply only to moving fluids (dynamic pressure) or if they can also be used for calculating force on an object due to static pressure. The static pressure in this case is due to static pressure rise across a normal shock in a supersonic wind tunnel.
The normal shock is a result of the supersonic flow not being fully established across the width of the tunnel, so that one side of the test model sees supersonic conditions and the other does not, with the two sides separated by a normal shock. In my case, the maximum static pressure is 22 psi and is much more harsh than any of the nominal drag forces on the model.
If I can use a drag coefficient of .5 for example for a cylinder, the force would be 1/2 of what it would be if it were simply pressure times area.
Jim Buckley
ASRC Aerospace
Cleveland
The normal shock is a result of the supersonic flow not being fully established across the width of the tunnel, so that one side of the test model sees supersonic conditions and the other does not, with the two sides separated by a normal shock. In my case, the maximum static pressure is 22 psi and is much more harsh than any of the nominal drag forces on the model.
If I can use a drag coefficient of .5 for example for a cylinder, the force would be 1/2 of what it would be if it were simply pressure times area.
Jim Buckley
ASRC Aerospace
Cleveland
