Abstract: The rocket sled can realize supersonic speed in a short time with horizontal boost sliding, which is not only the main means of current high-speed ground dynamic test, but also an important supporting carrier for the future reusable Single Stage to Orbit (SSTO) for the horizontal launch. Aiming at the key problems such as raising/lowering the head of the payload when it is separating from the sled, and the sensor layout scheme design for rocket sled testing, based on the high-precision turbulent numerical theory and the complex shock wave system interference theory, the hypersonic standard model is used as the payload to carry out the research on the aerodynamic mechanism of the rocket sled horizontal boost sliding system. By analyzing the evolution of vortex system, local flow field characteris-tics and overall aerodynamic characteristics of the structure at sliding speed across the speed domain, the influence mechanism of different connection schemes on the payload and the variation law of the structure surface pressure distribution are revealed. The results show that at low Mach number, the pressure fluctuation in the low pressure region changes periodically, which is easy to cause aerodynamic vibration; At different Mach numbers, the location of the low pressure zone changes obviously and the region expands with high velocity, and the wake vortex is rela-tively stable; Changing the connection distance and connection height can greatly change the vortex position in the low-pressure region.

Key words: Cross speed domain, Horizontal boost sliding, Internal vortex system, Shock wave interference, Rocket sled