CFD Analysis of Convergent-Divergent Nozzle for Low Altitude Rocket

Abstract

The convergent-divergent nozzle in rocket engines is used to turn the chemical energy developed via the combustion chamber into kinetic energy. The wall of the nozzle is properly contoured to efficiently accelerate the combustion product towards the nozzle exit. However, for low-to medium-altitude rockets (typically within the range of 10 to 145 km), nozzle contouring increases the overall production cost due to a more complicated fabrication process. The development of the dual conical nozzle seeks to compromise between performance and ease of fabrication. The present investigation seeks to analyze small rocket nozzles involving a typical conical nozzle, Truncated Optimized Contour (TOC) and Truncated Idealized Contour nozzles and newly designed dual conical nozzles. Rocket nozzles with various divergence angles and exit area ratios are numerically analyzed. It was discovered that the best dual conical nozzle can produce an average thrust comparable to that of a standard conical nozzle. In some cases, the dual conical nozzle outperforms its conical and contoured counterparts. Keywords— Dual conical nozzle, TOC nozzle, TIC nozzle, shockwaves, thrust.