Abstract:
Many researches show that missiles propelled by ducted solid rocket ramjet is regarded superior at the aspects of firing range, velocity and maneuverability. To improve the unexpected defects of some solid fuel ramjet missiles, such as larger flight drag, poor static stability, larger trimming angle of attack and higher rudder effect, comparative studies of key components to the aerodynamic performance of the missile were fulfilled, a series of significant different models comparing to the basic missile configuration were established based on the aerodynamic characteristics of some components that exercise a major influence on the missile performance. Using the CFD software Fluent, the missile flow fields with different attack angles were simulated numerically, and corresponding axial force coefficient, normal force coefficient and pitching moment coefficient with variety of attack angels were obtained, the pressure distributing trend were analyzed. The results indicated that, in terms of the optimization target, configuration with larger size inlet, smaller wing, rudder surface of edge, sweepback rudder surface and horizontal tail is superior to others. To validate this analysis, an experiment were carried out in the FD-06 hypersonic wind tunnel. The key components were installed on the missile body step by step by building up method. Totally, 16 models were tested, and the test results indicated that the optimal shape showed the consistent with the optimal model obtained by CFD analysis. Comparing to the basic missile, various performances of the optimized model were improved obviously under the studied conditions, the axial force coefficient decreased about 3.0%~4.0%, the longitudinal focus position moved backwards about 3.0% and the balance angle of attack decreased about 1.5°(60%), and the pitching and rolling rudder effect reduced 40% and 35% respectively. Furthermore, CFD results agreed well with the test results, and the reasonableness of CFD numerical methods instead of tunnel test results in the process of aerodynamic optimization were verified.