Gao's interacting shear flows (ISF) theory and its inferences and their applications

Gao's viscous/in-viscid interacting shear flows (ISF) theory, proposed by professor Gao Zhi in Institute of Mechanics, China Academy of Science, and its inferences and their applications in computational fluid dynamics (CFD) are reviewed and some subjects worthy to be studied are proposed in this paper. The flow-field and motion law of ISF, mathematics definition of strong viscous shear layer flow in ISF, ISF equations, wall-surface compatibility criteria (Gao's criteria), space scale variety law of strong viscous shear layer reveals flow mechanism and local space small scale triggered by strong interaction that cause some abnormal severe local pneumatic heating phenomenon in hypersonic flow. Gao's ISF theory was used in near wall flow, free ISF flow simulation and design of computing grids, Gao's wall-surface criteria were used to verify calculation reliability and accuracy of near wall flows, ISF theory approximate analytical result of shock waves-boundary layer interaction and ISF equations were used to obtain the numerical exact solution of local area flow (such as stationary point flow). Some new subjects, such as, improving near-wall turbulent models according to the turbulent flow simulation satisfying the wall-criteria and illustrating relation between grid-convergence based on the wall criteria and other convergence tactics, are suggested. The necessity of applying Gao's ISF theory and wall criteria is revealed. Difficulties and importance of hypersonic viscous/in-viscid interaction phenomenon were also emphasized.