Session KK - Acoustics.
ORAL session, Tuesday morning, November 20
Columbia 1 and 2, Marriott Hotel and Marina San Diego
A new concept for a missile scale hypersonic wind tunnel that will provide a Mach number from 7 to 12 at true flight conditions is presented. This new concept is based on ultra high pressure conditions (up to 23 kBar) and energy addition, using a high power electron beam, to the supersonic airflow in the expansion section and downstream from the throat. In this way the stagnation temperature upstream of the throat can be kept very low. Very important aspects of the hypersonic wind tunnel design are the heat transfer rates to the wall and to a lesser extent the boundary layer displacement thickness. Since the electron beam heating region is controlled by an applied magnetic field, the heated core has been designed to be largely isolated from an unheated outer flow. Euler simulations predict that the expansion to the test-section will cause the outer unheated flow to condense in the free stream. Viscous calculations however indicate that practically all of this two phase flow would be eliminated by heating in the turbulent boundary layer at the wall. The Reynolds number for the boundary layer in the heated region is 1.8E+9 based on distance from the throat (0.16m) and throat static conditions. The thermodynamics and fluid mechanics of the real gas flow field and the heat transfer to the wall at these extreme flow conditions are discussed from both a physical and computational point of view.