NUMERICAL SIMULATION OF SECONDARY INJECTION IN C-D NOZZLE IN THRUST

Abstract: Fluidic thrust vectoring provides an additional control variable that offers many benefits in terms of maneuverability and control effectiveness in the new generation aircrafts and missiles. Thrust vectoring capabilities make the satisfaction of take-off and landing requirements easier. Fluidic thrust vectoring continues to work at low dynamic pressures, where other control technologies are less effective, making it a more valuable and dynamic in flight envelope. Additionally, thrust vectoring could increase conventional controls for some control power to trim the aircraft and thus reduce cruise trim drag. In this paper, an attempt has been made to numerically study the effect of thrust vectoring using shock vector method for various pressure ratios (Nozzle inlet pressure to Secondary injection Pressure) and the jet deflection angles are obtained. Also aims to study the effect of nozzle blockage effects for each pressure ratios. The numerical study includes two different inlet pressure conditions namely 9 and 12 bars, with the secondary injection pressure ratio varied from 9 to 15 bars. The numerical study is based on the K-epsilon turbulence model with enhanced wall treatment to capture the complex flow phenomena occurring on upstream and downstream of the secondary injection port. The primary jet decay characteristics at the nozzle exit and the side forces created on the nozzle walls are studied.

Keywords: C-D nozzle, Thrust vectoring, Flow deflection, flow separation, fluidic thrust vectoring, shock vector