Studies Of Lateral Jet Control On Endoatmospheric Interceptor

Lateral jet control technology is researched in this dissertation, based on supersonic/hypersonic missile aerodynamics and lateral jet interaction (JI) effects associated with the attitude control solid-propellant rocket motors system in the low endoatmospheric range. The main contents of this dissertation can be summarized as follows:1. Numerical investigation of three-dimensional steady jet-interaction phenomenology. ( 1 ) Aerodynamics characteristic is calculated by using Renolds-averaged Navier- Stokes equations discretitted in cell-centered finite volume framework and improved on Baldwin-Lomax turbulent model for the slender body at the high angle of attack. The computed pressure distribution along the body surface show good agreement with the experimental data. Designed program is capable to solve complex vortex flowfield and detailed aerodynamic design problems with high fidelity engineering analyses. ( 2 ) To evaluate the effects of a reaction control jet on the aerodynamic performance of a missile operating at supersonic/hypersonic flight condition, the single and two attitude jet-interaction flow between a lateral jet and the external flow has been analyzed by detailed numerical simulation. The investigated performance characteristics of lateral jet interaction include pressure fields, flow field pattern and surface pressure distribution with jet on or off in the streamwise direction.2. Numerical simulation of 3-D unsteady jet-interaction phenomenology. (1) In time, an implicit time-marching second order accurate scheme is derived. Nonphysical time is introduced and the lower-upper symmetric successive over-relaxation (LU-SSOR) scheme is modified in Navier-Stokes equations. An application to natural unsteady viscous flow is presented to check for the capability of the procedure. (2 ) Transient jet-interaction phenomena, challenge project, is analyzed by computational unsteady aerodynamic method. Boundary condition of transient jet is established. Detailed transient jet-interaction flow visualization studies highlight the complex nature of the three dimensional interaction phenomena and provide insight into the physics of the flow structure. Although these pressure field variations are subtle, they translate into fairly large effects on normal force and pitching moment that allows us to explain why the transient jet/hypersonic-flow interaction enhances the effect of the jet reaction force in the jet startup and shutdown. The extensive study of the control effects due to the transient nature of jet startup and shutdown increase design understanding for autopilot tuning and sensitivity studies, ground and flight tests data analysis. The only remaining challenge to our understanding of JIphenomena for the jet control is the completion of our investigation into JI-inducedradiance over the seeker window.3. Research of experiential prediction method for aerodynamic characteristics of jet interaction. Based on momentum theory and shock wave gas dynamic theory, jet equivalent body idea and bow sharp wave mathematic formula is brought forward. The aerodynamic pressure expression at jet location and in the area of jet interaction is established by blast wave principium. Taking advantage of hypersonic panel method, the analysis predicts lateral jet aerodynamic interaction for a blunted body in a hypersonic flow. The computational results show better agreement with the experimental data. At the initial stage of vehicle design, the contributed engineering approach provides a powerful backing for prediction jet aerodynamic characteristics.4. JI effects. Author does the work in defining transient jet interaction factor concept and establishing mathematic model. Transient jet interaction factor changing with chamber press is calculated. The impulse thruster control force model to analyze missile JI control effects may be as a result of actual design reference.5. The six-degree-of-freedom mathematical model and...