Mechanism of separation hysteresis in curved compression ramp

A new spatial-related mechanism is proposed to understand separation hysteresis processes in curved compression ramp (CCR) flows discovered recently (Hu et al. Phy. Fluid, 32(11): 113601, 2020). Two hystereses, induced by variations of Mach number and wall temperature, are investigated numerically. The two hystereses indicate that there must exist parameter intervals wherein both attachment states can be established stably. relationships between the aerodynamic characteristics (including friction, pressure heat flux) shock wave configurations this analyzed. Further, adverse gradient (APG) Isb(x) upstream process APG Icw(x) downstream isentropic estimated classic theories. trend boundary layer resistence Ib(x) evaluated from spatial distributions physical quantities such as shape factor height sound velocity line. With stable conditions attachment, a self-consistent obtained when Isb, Icw Ib have appropriate distributions.