Effect of geometry and operation conditions on transient response characteristics for the static cavity

In the transient process or the emergency situation of engine, the fluctuation of the secondary flow is not consistent with the mainstream. In pursuit of safety during transient state, transient response characteristics for the system and components become an important subject. This paper focuses on a static cavity connected multi-holes, which has pretty evident characteristics in the system, and the object is to establish a similarity model to deduce the pressure at different time and to carry out experiments to evaluate some effects in the form of non-dimensional parameters. Based on the adiabatic assumption, the similarity analysis for a cavity connected multi-holes is carried out based on the adiabatic assumption. The non-dimensional gradient pressure can be expressed as the function related to non-dimensional area, pressure, and discharge coefficient. Then, a series of experiments have been carried out. The first group of experiments is used to obtain the effect of different levels of the inlet pressure disturbance. The results show it affects the response pressure significantly, but the change of the response time coefficient is not obvious. Also, another group of experiments are set to identify the effects of the different positions of exit or feed holes, and no distinct difference is observed. The third group are set to measure the transient response processes for the cases with the different area of exit holes or feed holes. The response regulation of the dimensionless pressure is related to the area ratio of the feed holes to exit holes.