Computational study on flow through truncated conical plug nozzle with base bleed

Prasanth P. Nair ^a, Abhilash Suryan ^a,*, Heuy Dong Kim ^b

a. Department of Mechanical Engineering, College of Engineering Trivandrum, Trivandrum 695016, India
         b. Department of Mechanical Engineering, Andong National University, Andong 760749, Republic of Korea

Abstract: Conical plug nozzle and truncated conical plug nozzle are advanced rocket nozzles suitable for use as altitude compensating nozzles. In this study flow through the conical plug and truncated conical plug nozzles are numerically simulated to first validate with experimental data and then to compare the performance when a base bleed is introduced. The numerical analysis has considered two-dimensional axisymmetric models. Reynolds-averaged Navier-Stokes equations are solved with two equation shear stress transport k-ω turbulence model. For the validation of the plug nozzle, flow features and wall pressure along the length of the nozzle is taken for different nozzle pressure ratios. For the validation of truncated plug nozzle, flow features and base pressures at various nozzle pressure ratios are compared. The base bleed is taken as 2% of the inlet mass flow rate. The comparison of results shows that the introduction of base bleed helps to compensate for the loss of thrust due to conical plug nozzle truncation.

Keywords: Plug nozzle; Aerospike nozzle; Advanced rocket nozzle; Reynolds-averaged Navier-Stokes (RANS); Base pressure; Coefficient of thrust; Base bleed; Secondary flow