Thrust-vector control(TVC) via injection of a secondary jet has drawn much attention since 1960`s. One of the recent investigations is exploring benefit of the fluidic nozzle control which has revealed that significant thrust-vector angles could be generated by a secondary airstream injected into the divergent section of a nozzle. By using a fluidic control in place of mechanical, significant portion of the nozzle hardware could be hidden inside the airframe structure. This structural integration would eliminate kinematic or mechanical moving parts like actuators, affording significant reduction in nozzle weight, cost and complexity.
Accurate analysis of nozzle-secondary jet combined flow is of prime importance in the design of TVC. For the gas-only one-phase nozzle flows, numerous papers have appeared characterizing the performance of the TVC. In the case of solid rocket motors, significant loss of nozzle performance is observed due to the condensed metallic oxide particles produced as combustion product in the flow field. Exchange of momentum and energy between the accelerating gas and particle phases definitely alters the TVC variables. There have appeared not enough investigations regarding the gas-particle interaction mechanism affecting the TVC.
In the present thesis, we have numerically analyzed the dilute particulate gas flow in the two-dimensional convergent-divergent (2DCD) nozzle with a transverse jet for TVC. The solutions to the Eulerian gas and Lagrangian particle equations are obtained taking the inertial effect of the particles into account. Numerical formulation is made on the gas-phase part with the Navier-Stokes equations supplemented by a two-equation k-ω turbulence model. The computer code is based on the upwind-difference scheme for the convection terms and the LU-SGS scheme for temporal integration. The solid particle phase, on the other hand, is solved by a Lagrangian particle-tracking scheme. The effect of particle motion on the gas phase is numerically implemented by the PSIC method, the source terms of which evolve to a steady state as iteration is made in time direction.
The present study simulates the particle effect of a solid rocket motor booster under thrust vectoring. To verify accuracy of the computer code first, the slot injection from the surface of a flat plate into a turbulent supersonic stream is calculated for the gas-only flow. The JPL nozzle for the two-phase flow is also calculated. To investigate the flow field in a 2DCD, the thrust vector angles obtained by computational result are compared with the experimental data over a range of secondary to primary injection mass flow ratios and nozzle pressure ratios for the gas-only flow. The 2DCD nozzle flow for the gas-particle mixture is then solved to estimate the effect of particle on the performance of thrust vectoring. The detailed characteristics of two-phase 2DCD nozzle with TVC are elaborated in the Results and Discussion section.
