Study on Separation Characteristics of Nozzles with Large Expansion Ratio of Solid Rocket Motors

In order to study the flow characteristics of a nozzle with large expansion ratio and its influence on force nozzle, ground cold test research fluid–structure coupling simulation analysis were carried out (maximum ε = 30.25). The variation pulsation pressure near measuring point area inlet obtained through experiments. Through peak-to-peak value average value, it was found that after separation increases by 90%, but about five times, indicating fluctuation is much larger than before separation. field under conditions simulated using CFD commercial calculation software Fluent verify correctness numerical calculations. 48) full-scale structural deformation studied. results show occurs in conditions. Before point, wall small, turbulent effect weak. After increases, enhanced. When total decreases, presents strong asymmetry. Reducing half resulted approximately 50 times lateral load. Under combined low pressure, load caused asymmetry will cause structure increase 5.5 times. This provides an important reference for design experiment nozzles ratio.