NONLINEARLY UNSTABLE WAVES DOMINATED BY ENTROPY MODE

This paper is concerned with instability of flow fields which are domi nated by the entropy mode with the presence of usual acoustic and vort ical modes. These combined modes lead to nonlinear unstable waves whic h may occur in automobile, aircraft, or rocket engines. In this study instability in a side-burning rocket is investigated. It is shown that the energy growth rate parameters increase with an increase of the en ergy growth factor. The energy growth rate parameters for turbulent fl ows are larger than those for laminar flows. It is further shown that unstable wave motions for the high-temperature side-burning rocket are dictated mostly by the entropy mode, somewhat by the vortical mode, a nd least by the acoustic mode.