Accession Number : ADP006047

Title :   Shock Tunnels for Real Gas Hypersonics,

Corporate Author : QUEENSLAND UNIV BRISBANE (AUSTRALIA) DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Stalker, R. J.

Report Date : NOV 1987

Pagination or Media Count : 10

Abstract : The application of free piston shock tunnels to the simulation of real gas effects in hypersonic flight is discussed. It is pointed out that the primary simulation variables for this purpose are the stagnation enthalpy and the binary scaling parameter. The free piston reflected shock tunnel is considered first, and it is shown how test time limitations play a major role in determining the limiting stagnation enthalpy for a given model size. Nevertheless, flight values of the two simulation variables, for vehicles similar to the Space Shuttle Orbiter, can be matched by an existing free piston shock tunnel up to speeds of 7 km/s. Experiments performed in this shock tunnel are used to demonstrate real gas effects in model flows. Radiative energy loss limits the maximum stagnation enthalpy available with reflected shock tunnels. Fortunately, operation in the non-reflected mode circumvents this limitation and, in addition, allows higher values of the binary scaling parameter; although it also leads to greatly reduced test times. The use of the prior steady flow technique to enable high enthalpy non-reflected shock tunnel operation is described, and examples of experiments performed in facility are used to demonstrate that short test times do not preclude worthwhile experimentation. A variant of the free piston shock tunnel, which is intended for propulsion research at high velocities, also is briefly described.

Descriptors :   *SHOCK TUBES, *HYPERSONIC WIND TUNNELS, STAGNATION POINT, ENTHALPY, PISTONS, HYPERSONIC CHARACTERISTICS, RADIATIVE TRANSFER, HEAT LOSS, STAGNATION TEMPERATURE, SYMPOSIA.

Subject Categories : Fluid Mechanics
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE