IMPACT OF INTAKE BOUNDARY LAYER TURBULENCE ON THE COMBUSTION BEHAVIOR IN A SCRAMJET

The present investigations focus on the mixing and combustion en-hancement capabilities of a boundary layer entering a combustion cham-ber. Numerical investigations for both a generic con¦guration and a real ramp compression intake of a full-scale vehicle with a combustion chamber height of 0.3 m were performed. The §ow condition is chosen according to possible conditions in a scramjet combustion chamber with 1300-kelvin static temperature, 1-bar static pressure, and a Mach num-ber of 3. The results of this sensitivity study show that both mixing and combustion e©ciency are signi¦cantly increased due to the turbulence of the incoming boundary layer, whereas the required injector spacing to reach optimum mixing and combustion has to be increased. In addition to the classical porthole injection, an injection system with hypermixing capabilities was investigated which showed comparable sensitivities.