Numerical Study of Air-Intake Performance of a Scramjet with Various Cowl Lip Length

The development of a supersonic flow in the air intake is critical to the operation of a scramjet engine since it determines how well the engine performs. The configuration of the air intake plays a key role in determining whether or not the required pressure recovery of the intake is attained, which in turn affects the efficiency of the combustion chamber. This work presents the prediction of aerodynamics performance of scramjet’s intake at high Mach number flight using computational fluid dynamics. A scramjet intake with mixed compression is being used, and it has two external ramps. The work focused on the aerodynamics characteristics of the intake and the effects of the cowl lip length on the compression ratio inside isolator. CFD simulation was modelled for 2-dimensional, steady, compressible flow using rhoCentralFoam of OpenFOAM. The Mach numbers were ranged from 5 to 6.5, angle of attacks (3°, 0°, and −3°) and flight altitude of 26 km. The results show an improvement in compression ratio (static pressure, and static temperature) up to 20% in addition to increment in mass flow captured by 16.7%.