Rui Xiaoting

Transfer Matrix Method for the Determination of the Natural Vibration Characteristics of Realistic Thrusting Launch Vehicle—Part I

The feasibility of using the transfer matrix method (TMM) to compute the natural vibration characteristics of a flexible rocket/satellite launch vehicle is explored theoretically. In the approach to the problem, a nonuniform free-free Timoshenko and Euler-Bernoulli beamlike structure is modeled. A provision is made to take into consideration the effects of shear deformation and rotary inertia. Large thrust-to-weight ratio leads to large axial accelerations that result in an axial inertia load distribution from nose to tail which causes the development of significant compressive forces along the length of the launch vehicle. Therefore, it is important to take into account this effect in the transverse vibration model. Once the transfer matrix of a single component has been obtained, the product of all component matrices composes the matrix of the entire structure. The frequency equation and mode shape are formulated in terms of the elements of the structural matrices. Flight test and analytical results validate the present TMM formulas.

Aerodynamic and static aeroelastic computations of a slender rocket with all-movable canard surface:

The present paper is undertaken to better understand the impact of the all-movable canard surface on the aerodynamic and static aeroelastic of slender rocket. Numerical simulations are performed to numerically calculate the guided rocket aerodynamic coefficients using commercial steady-state Computational Fluid Dynamics software ANSYS®-CFX. The variations of lift and drag coefficients with Mach number are demonstrated in the linear range of angles of attack. Comparison is made between the aerodynamic results and experimental data, which verified the accuracy of the fluid domain numeric method. Rocket static aeroelastic study is simulated through the inertia relief approach and fluid–structure interaction two-way loosely coupled methods based on multi-physics coupling platform ANSYS Workbench. Comparisons are also made between the results and AGARD 445.6-Wing standard model. Moreover, the composite material is carried out to improve the canards strength. Numerically, it indicates that deflected angle of all-movable canard surface has remarkable effect on the aerodynamics of the rockets. Aerodynamic loads are mainly contributed to the static deformation of the flexible rocket, while thrust effect is tiny and may ignore. The static deformations push the center of pressure forward and increase the trim angle. By product, rocket control effectiveness is decreased about 38%. Canards with the original material experiences stresses beyond the allowable due to static deformation at high supersonic speed. Hence, composite material is adopted for strengthening the canards.