The present paper presents numerical investigations of the internal flow field in a nozzleless solid rocket motor chamber with compressible transpiration and endwall disturbance. More attention is given for predicting the induced turbulent flow inside the chamber. The considered physical configuration of the nozzleless solid rocket motor consists of a two-dimensional rectangular and porous chamber fitted at the head end with a specifiedfrequency-oscillating piston and it is opened to atmospheric plenum in the downstream direction. The numerical study is performed by solving the unsteady RANS equations along with the energy equation using the control volume approach on the basis of a staggered grid
system. Different two-equation turbulence models have been implemented and their accuracy is estimated through a comparison with the available experimental measurements. A fairly general agreement has been obtained between the numerical and the experimental results. Moreover, the obtained results showed that complex turbulent internal flow patterns are induced inside the chamber due to the strong interaction of the sidewall injection with the traveling acoustic waves. Such complex internal structure is shown to be dependent on piston frequency and sidewall mass flux.