Design and Thrust/Weight Optimization of a Supersonic Plug Nozzle by Truncation

Abstract

The popular problem for space propulsion researchers is fuel consumption, which is associated with the weight of the vehicle, and from there, any weight gain leads to fuel gain. We studied the weight reduction of the supersonic nozzle of a space vehicle without any significant effect on the thrust. We first created the contour of the plug nozzle using the method of characteristics, According to the analysis of the pressure profile on the wall of the Plug nozzle we notice that the pressure first decreases very quickly in the initial expansion area, at the level of the col, and continuously decreases in the divergent part before it stabilizes at the tip of the nozzle, approaching the atmospheric pressure value at the outlet of the nozzle. So the last part of the divergent is substantially constant. Therefore, if truncated in this part, this does not lead to a significant decrease in the maximum thrust. In this study, we truncated an ideal supersonic plug nozzle into four different points and we have four Plug nozzles of different lengths and maximum thrust as well. We then choose the Plug nozzle which has an optimized thrust/weight ratio. Finally, we have a Plug nozzle with significant weight gain and a slight maximum thrust loss compared to the ideal plug nozzle.