A mathematical model for the characterization of fluid transients in cryogenic propellant feedlines

A mathematical model formulated based on the method of characteristics is presented in the current article to predict fluid transients occurring due to the sudden closure of the valve in cryogenic propellant feed systems. The applicability of the developed model was evaluated by comparing its predictions with the results available in the literature for cryogenic fluid as well as for water. From the results, it was found that the dampening of the pressure wave largely depends upon the modelling of unsteady friction. Further, the mathematical model was used to investigate the effect of valve closing strategies viz; instantaneous, concave, linear and convex closure on the fluid transients. It was observed from the study that the peak pressure of the oscillations could be reduced by use of linear closure of the valve.