Closing Characteristics of a Main Oxidizer Shut-off Valve

We study the closing characteristics of a self-sustainable poppet valve which serves as a main oxidizer shut-off valve for liquid rocket engines. Numerical analysis for predicting closing transient responses are presented and the calculated results have been verified by a comparison with experimental data. The effective area of a pilot gas discharge system and the pressure distribution of passage flow around the valve moving part are shown to be main parameters in determining the closing characteristics for dry and cryogenic conditions, respectively. Moreover, it is presented that the passage flow pressure at the valve closing moment as well as the valve closing velocity can be effectively adjusted by the appropriate employment of the pilot gas.