Aerodynamic Damping of a Hammerhead Launch Vehicle in Transonic Flow

摘要

The aerodynamic damping of a hammerhead launch vehicle was measured at Mach numbers from 0.7 to 1.05 using a flexibly mounted elastic model.The scaled elastic model which looks like a central aluminum tube was designed to simulate the full-scale vehicle mass ratio parameter and reduced frequency.The elastic model was supported on a sting by leaf springs at the node points of the first free-free mode.An electromagnetic shaker was used to excite the model in its elastic bending modes of vibration with the wind on.The aerodynamic damping in each mode was determined by measuring the total damping with the wind on and subtracting from that value the structural damping ratio determined with the wind off.ERA method was used to identify the damping of each mode with or without wind on.The experimental results showed that near mach 0.9 the aerodynamic damping became lower than the results of the mach numbers nearby.