SPACE-TIME FINITE-ELEMENT COMPUTATION OF COMPRESSIBLE FLOWS BETWEEN MOVING COMPONENTS

A numerical simulation capability for the injector flow of a regenerat ive liquid propellant gun (RLPG) is presented. The problem involves fa irly complex geometries and two pistons in relative motion; therefore a stabilized space-time finite element formulation developed earlier a nd capable of handling flows with moving mechanical components is used . In addition to the specifics of the numerical method, its applicatio n to a 30 mm RLPG test firing is discussed. The computational data fro m the simulation of this test case are interpreted to provide informat ion on flow characteristics, with emphasis on the tendency of the flow to separate from the injection orifice boundary of the test problem. In addition, the computations provided insight into the behaviour of t he flow entering the combustion chamber.