Research on Dynamics Characteristic of the Filling Liquid Tank

The dynamics characteristic of the rocket tank with liquid propellant in it, which takes the large part of a carrier rocket, make a great influence to the whole rocket. The tank of some model was investigated systematically by the PATRAN finite element software. Firstly, it established a finite element modal of the tank and calculated the modal frequency and shape of the empty or filling tank by the virtual fluid mass and acoustic-structure coupling analysis. Then, it contrasted the veracity and applicability of the two methods and investigated how the liquid depth and density and the middle clapboard's thickness influenced the immanent frequency of tank. Further, the filled tank's characteristic of response was researched by the coupled acoustic-structural analysis. Finally, it investigated how the liquid depth and density influenced the filling tank's characteristic of response. The main conclusions are shown below: 1.The result of the filling tank's modal is approaching to the test. 2.Augmenting the density of liquid reduces the modal frequency of tank and increases the pulsant pressure of liquid. 3.Raising the depth of liquid reduces the modal frequency of tank and increases the pulsant pressure of liquid. The paper's achievement and conclusion will help to avoid the coupling between the launch vehicle structure and propulsion system and improve the dynamic stability. It also can provide references for design of the new tank according to the result.