Fluid-structure interaction in hypersonic flows

Abstract

A Scramjet propulsion system is a form of airbreating jet engine using the high velocity of the air to compress it without a rotatory compressor. In scramjet engine the high vehicle speed is used to compress and decelerate the incoming flow to subsonic velocities before the combustion. Hypersonic aerodynamics are conventionally defined as those flows where the Mach number is greater than 5, but hypersonic flow can also be defined as the regime where some flow phenomena become more important as the Mach number increase. One of these phenomena is the origination of very high gas temperatures, which occurs due to the dissipation of the kinetic energy of a hypersonic flow by means of friction within hypersonic boundary layers. The high gas temperatures can lead to high thermal stresses in the solid structure, which can result in catastrophic failure. Therefore, an accurate analysis of the thermal loads from the fluid, as well as of the structure’s surface temperature, is essential. The thermal loads from the fluid affect the temperature distribution in the structure and the surface temperature of the structure is, in its turn, a boundary condition for the fluid. Thus, a partitioned coupling approach using a structural solver, a fluid solver and a coupling module has to be applied.