Reduced-length scarfed-nozzles for thrust vector adjustment

Abstract

The results of an investigation into the utilization of scarfed, truncated perfect-nozzles for thrust vector adjustment in tactical strap-on boosters is presented. The use of truncated perfect-nozzle expansion contours was evaluated as a means of achieving significant nozzle length reductions over conical nozzle designs without degrading axial thrust or thrust vector adjustment capability. Previously developed perfect-nozzle and scarfednozzle performance analysis computer codes were used to generate an extensive parametric study which characterized the influence of nozzle length and expansion ratio on axial thrust and thrust vector adjustment capability. Comparisons were made against the results obtained for scarfed-nozzles with conical expansion contours. The parametric study was utilized to develop a general scarfed truncated perfect-nozzle design methodology. This methodology was exercised to generate a specific reduced-length scarfed-nozzle design. The axial performance and thrust vector adjustment capability of the nozzle design was experimentally verified through solid rocket motor static firings.