Numerical investigation of pitch motion induced unsteady effects on transverse jet interaction

Abstract

Motion-induced unsteady effect is becoming one of the inevitable challenges for the improvement of high-speed and high-maneuvering projectiles performance under a transverse jet control. Therefore, three-dimensional, compressible, unsteady, Reynolds-averaged-Navier-Stokes numerical investigations are performed to illustrate motion-induced unsteady effects on transverse jet interaction. Two pitch motion types, including forced-oscillation and free-response-motion, were chosen to evaluate the potential effects. The current study found that time hysteresis and aerodynamic deviation appear comparing to steady counterparts. Forced-pitch-oscillation data indicate negative interaction-force-amplification-factors at a certain angle of attack while interaction-moment-amplification-factors show an obvious decrease at a relatively high angle of attack. Meanwhile, transverse-jet-controlled free-response-motion data, obtained through coupled CFD/RBD/JET method (a coupled method with CFD (Computation Fluid Dynamics) and RBD (Rigid Body Dynamics) under the control of a transverse jet), visualized positive enhancement of rear jet interaction, as the desired angle can be achieved in less time. Taken together, it is possible that motion-induced unsteady effects on transverse jet interaction may be underestimated and are worthy to be discussed deeply for energy-efficient and flight safety concerns.