Design and simulation analysis of mantle cavity of jet thruster

The research of aquatic-aerial multi-modal vehicle is becoming more and more popular. The key issue is how to provide enough power to drive the vehicle to complete the water-air crossing. Jet thruster is one of the important power sources. The flying squid absorbs water into its body and sprays water with its muscle barrier membrane to produce a reaction force, thereby completing the medium crossing. We call this structure of flying squid mantle cavity, which can be migrated to the jet thruster to optimize its propulsion effect. In view of the low efficiency of the actual experiment of the mantle cavity, this paper proposes to use Computational Fluid Dynamics(CFD) technology to simulate the fluid-solid coupling of the mantle cavity and establish a simplified model of it. On this basis, we designed three sets of comparative experiments about the structure, material and the liquid proportion of the cavity. The experimental results verify that the barrier membrane with different materials has the characteristics of small deformation and stable propulsion compared with the single barrier membrane. And the liquid cavity proportion of 50% can achieve a balance between deformation stability and outflow velocity stability, thereby reducing the difficulty of aircraft motion control.