Network Flow Simulation of Fluid Transients in Rocket Propulsion Systems

摘要

This paper presents a numerical study of fluid transients in a pipeline with the sudden opening of a valve. A network flow simulation software (Generalized Fluid System Simulation Program) based on the finite volume method has been used to predict the pressure surges in a pipeline that has entrapped air at one end of the pipe. The mathematical model is formulated by involving the flow equations in the liquid (water) zone and compressibility of the entrapped air. The numerical results are compared with the experimental data available in the literature. The study is conducted for a range of the reservoir pressure and for different amounts of initial air present in the pipeline. The numerical results compare well within reasonable accuracy (less than 8 %) for a range of inlet-to-initial pressure ratios when the amount of air present is relatively high (α ≈ 0.45). A fast Fourier transform is performed on the pressure oscillations to predict the various modal frequencies of the pressure wave.