Dynamic characteristic comparison between pressure fluctuations coupling with a moving part model of a liquid rocket engine flow regulator.

This article focuses on the development and validation of a three-dimensional transient numerical model to investigate the fluid–structure interaction (FSI) and dynamic response mechanisms of flow regulators in liquid rocket engines, specifically a high-thrust hydrogen-oxygen staged combustion engine's pre-combustion oxidizer flow regulator (POR). Using computational fluid dynamics (CFD) with dynamic mesh techniques and experimental validation (showing less than 3% error), the study analyzes the regulator's behavior under various sinusoidal and step pressure perturbations, examining parameters such as mass flow rate overshoot, sliding sleeve displacement, vortex evolution, and the effects of friction. Key findings include the proportional relationship between perturbation amplitude and flow overshoot, the influence of perturbation frequency on flow oscillations, and the critical role of friction in modulating the regulator's stabilization performance. The results provide insights into the negative feedback mechanisms governing flow regulation and offer guidance for optimizing flow regulator design in liquid rocket engines.