Advancement of Empirical Model for Stagnation Pressure Gain in RDCs

Abstract

View Video Presentation: https://doi.org/10.2514/6.2022-0834.vid This study describes the experimental characterization of an RDC across a broad parameter range. The operation and stagnation pressure gain of this device are quantified while varying the air injector area, the fuel injector area, the annulus width, the outlet throat area, the mass flow rate, and the equivalence ratio. It is shown that a reduction in annulus area coincides with an increase in wave speed and pressure gain, but potentially also reduces the operating envelope of the device. The narrower channel width also resulted in a transition to two co-rotating waves at a lower mass flow rate. Overall, no net positive pressure gain could be achieved, but the results compare well with previous studies and the anticipated performance. Data from 718 individual test runs are then used to fit empirical models with 6 to 10 coefficients. These models are expressed as functions of the most important geometric parameters and a flux-based value, either mass or power. For the best-performing model, an R² value of over 94% was achieved.