Part II: Numerical study on the flow and thermal characteristics of an integrated deflector under the periodic impingement of a supersonic high temperature jet

A three-dimensional numerical simulation of an integrated deflector under periodical impingement of a supersonic high-temperature air jet was conducted on the basis of the Renormalized Group (RNG) k-ɛ model. The heat capacity and thermal conductivity of the deflector materials as functions of temperature were measured to establish the model. The predicted transient temperature response of the impinged and back surfaces of the deflector agreed well with experimental data. The flow and thermal performance of jet impinging on the deflector were investigated, and the effects of separation distance, horizontal angle, and vertical angle were analyzed. The predicted results of the experimental case revealed that the impingement jet generated a shock wave at the plate center and an expansion wave at 0.5D < y < 1.5D. The maximum pressure, Nusselt number, and temperature on the impinged surface displaced from the geometric impingement center at y = −0.3D, y = −0.1D, and y = 0.3D, respectively. Parameter analysis revealed that larger separation distance resulted in lower maximum pressure. The peak of maximum Nusselt number occurred near the end of the potential core of the free jet with the same parameters, whereas the maximum temperature appeared prior to the end of the potential core. When the horizontal or vertical angle decreased from the perpendicular case at 90°, the asymmetry of wall jet distribution in the corresponding direction was augmented. This condition decreased maximum pressure, Nusselt number, and temperature, but increased the displacement of maximum points from the geometrical impingement point.