Impacts of panel vibration on shock train structures and performance of two-dimensional isolators

As one of the most critical components in scramjet engines, isolators are designed to prevent the hypersonic inlets from pressure disturbances raised from combustors. Shock trains dominate the internal flow field of isolators, the characteristics of which is crucial to the performance of isolator. However, recent studies have primarily focused on rigid isolators without structural deformation. The impact of structural vibration on the flow structures and performance of isolators receives little attention. The current study focuses on this problem by investigating the effect of vibration panel at the foot of shock train on the flow and performance of isolator which is quantified by 11 parameters regarding separation zone, shock structures, flow asymmetry, and isolator performance. Results examine the difference due to vibration amplitude, frequency and wavelength. Analyses indicate that the panel vibration will cause the upstream movement and length increase of shock train and separation zones, the increase of flow asymmetry and decrease of isolator performance. With increasing vibration amplitude, the shock train and separation zone travel upstream with the increase of shock train length, the flow asymmetry increases with large transient side loads, and the influence on the performance of isolator isminor. With increasing vibration frequency, the shock train and separation slightly travel downstream with the decrease in length, the change of flow asymmetry is minor with large transient side loads and the change of performance is minor. With increasing mode number (decreasing wavelength), the shock train and separation zones move downstream with the increase of shock train length, the flow asymmetry increases with significant transient side load at 2nd structural mode, and the change of performance is minor.