Numerical Study Of Flow Filed For Newly Designed Energy Dissipators In Pressurized Tanks

During the tank pressurization process in a gas pressurized rocket tank, the impact on liquid propellant surface caused by pressurized gas with high speed might lead to splashing of liquid fuel and fall of temperature and loss of pressure in tank ullage, which will finally make it unable to satisfy the minimum requirement of the engine pump. New tank energy dissipators are designed to ensure that the transportation of pressurized gas is safe and steady,the pressure requirement of tank ullage and engine pump can be maintained, and the disturbance of tank ullage and propellant is diminished.In this paper, basic theory of fluid mechanics is applied to found mathematical models for tank pressurized gas energy dissipators. Then numerical method is used to study six kinds of due tank pressured gas energy dissipators, including horn energy dissipator, perforated cylinder dissipator, dissipator with horizontal flow, dissipator with longitudinal flow, dissipator I with multilayered perforated cylinders, dissipator II with multilayered perforated cylinders. According to the numerical results, the deceleration efficiency of each dissipator is calculated and their dissipation mechanism are analyzed, through which we find that energy dissipators with splitter in upstream an multilayered perforated cylinders in downstream are more effective than others.Drawing on the method and experience of energy dissipator designing in structural engineering, hydraulic engineering and noise reduction engineering, combined with numerical results for each tank energy dissipator in this paper, we proposed engineering design method for tank pressurized gas energy dissipator. On this basis, we designed two kinds of optimized structures for perforated cylinder dissipator and simulated their flow filed distribution, with whose results, we find that the optimized structures are more effective in controlling the velocity of pressurized gas and balancing the equitability of the flow distribution. Finally we can say this engineering design method for tank pressurized gas energy dissipator is reliable.