Effects of plug sidewall on linear plug nozzles performance

To understand the effects of plug sidewall on linear plug nozzles performance, sidewalls with different geometries and heights were brought forward. All of these sidewalls were fit on one plug. Numerical method was employed. Flow fields and performances of plugs with different sidewalls were obtained. Ways of sidewall affecting plug nozzles' performance were found: efficiency of plug nozzles with curve sidewall was a bit larger than that of plug nozzles with line sidewall, not more than 1%; removal of sidewall could reduce plug nozzles performance by 4%-6%; sidewall's height should not lower than internal nozzle exit, otherwise plug nozzles performance would be lowered; when sidewall height exceeded internal nozzle exit, increasing of sidewall height did not change plug nozzles performance. At last, Flow field structures of plugs with different sidewalls were qualitatively analyzed. Reasons of leading to such effects were found.