Predictions And Analysis Of Pitching Dynamic Derivatives For Rocket

Along with the developing of aeronautic technology,many projectile will be in flight status which have a high angle of attack and high speed.Pitch dynamic derivatives has become the important parameter in the projectile design and occupies an important position in the projectile dynamic characteristics analysis,trajectory design and control system design.In this thesis,use the internet dynamic derivative standard model,Finner,as the research objective,the application of rigid dynamic mesh technique in predicting pitch damping dynamic derivative was calculated and verified,and then the factors of this method were analysed.On this basis,the calculation to the pitch damping dynamic derivatives of canard configuration rocket were futher explored,as well as its change rule along with the initial conditions.Firstly,using the implicit iteration method of space-time second order accuracy based on N-S equations and combining the rigid dynamic mesh technique,numirical calculation of pitch damping dynamic derivatives was researched by adopting small amplitude forced longitudinal vibration method.Using an internet dynamic derivative standard model,known as the Basic Finner,as the research objective,the influences of near wall treatment,reduced frequency,oscillation amplitude,period iterations and inner iterations for pitch damping dynamic derivatives were studied,as well as the influences of the initial angle of attack and center of mass.The good agreement of calculation results and experiment results shows that the method used in this thesis has a high accuracy and the calculation condition is feasible.Based on the study on Basic Finner,the change rule of pitch damping dynamic derivative,varied with initial angle of attack,Mach number and position of the center of mass,was futher researched.Studes have shown that the selection of compute condition has great influence on calculation efficiency and results of pitch dynamic derivatives,especially period iterations and reduced frequency.To the canard configuration rocket,the change rule of its pitch damping dynamic derivative varied with angle of attack and Mach number keeps the same as the change rule of its pitching moment coefficient.