Predicting liquid manifold priming event peak pressure levels through numerical modeling

A study was conducted to evaluate the ability of a numerical model to predict priming event peak and transient pressure levels inside unrestricted test elements representing liquid monopropellant propulsion system manifolds. The mathematical model was embedded in a commercial multi-physics system-level simulation software called GT-SUITE. Through user-defined initial conditions and input parameters, the model calculated pressures at node locations throughout the interior of the test element. Extensive experimental priming event literature was used to validate the numerical model under various pre-test pressure conditions to evaluate the accuracy of the results. Differences in the experimental literature evaluated included test element internal diameters, line lengths, manifold layouts, and flow control valves. Based upon the results, it was determined that the numerical model was a promising tool to predict liquid system pressure transient levels, with accuracy to within ±20 of the experimental literature results.