TWO PHASE FLOW ANALYSES OF MOVABLE JET NOZZLE

Abstract

In the current study, 2D Movable Nozzle is used to simulate and analyze the effects of Thrust-Vector Control (TVC) in Solid Rocket motors in two-phase flow regime. The thrust creating part of the rocket is its nozzle. Rocket efficiency is purely dependent on the Mach No. and thrust. When two phase flow inside the nozzle domain is injected or created, thrust produced that is relatively smaller than single phase flow. This phenomenon is because of the reduction of Mach No. due to the agglomeration of particles of two phase flow at the nozzle throat. Mach No. is also affected by the Thrust Vector control (TVC). Thrust vector control is only possible when the propulsion system is working and creating thrust. Thrust-Vectoring control (TVC) is completed by the deflection of aircraft or rocket nozzles which results in pitch, yaw and roll direction. The burning of Aluminium-fuel within the combustion chamber of Solid Rocket Motor (SRM) is the reason of production of two-phase flow (gases and solid particles that are called alumina) in the nozzle domain. Mach no. of the gas is affected by the alumina (solid particles). These particles are gathered at the throat of nozzle which can decrease the thrust. Such challenging effects in the nozzle are due to the two phase flow and Thrust Vectoring Control (TVC) makes this study more important for Computational Fluid Dynamics (CFD) experts and rocket propulsion engineers. In the present study, Two-dimensional Movable nozzle is used, that is capable of not only directing the thrust along the axis of the engine, but also can deflect to vector the thrust and produce a force that points the nose of the rocket in a different direction. This type of nozzle is the most significant part of x thrust vectoring. Such nozzle can do vectoring the thrust up or down by producing an up force or down force. Down force will force the rocket nose to pitch upward direction while the up force will force nose to downward direction or used for maneuver. There are primarily two models to analyze the two-phase flows in CFD; one is Eulerian-Eulerian model and the other is Eulerian-Lagrangian model. For simulation in Fluent, Eulerian-Eulerian model is used to investigate the effect of Thrust Vector Control with two phase flow. Firstly this effect is examined with single phase flow that is Laminar flow then two-Fluid model is taken under study. The Movable Nozzle is deflected with respect to the axis of the nozzle from 0 0 to 200 using the upward force. The deflection of the nozzle gives the Thrust Vector Control to the rocket or air craft.