Numerical simulation of fuel supply of multi-tandem fuel tanks in flight vehicle

Multi-tandem fuel tanks have a complex structure, low flow rate between tanks, and, unlike single-fuel tanks, uneven pressure distribution, which makes their fuel supply and pressurization difficult to control. This paper uses a volume-of-fluid model based on the finite-volume method to track the fuel motion in different states of a flight vehicle and obtains the liquid-surface sloshing and the liquid flow in the connecting pipe. The model uses the dynamic meshing technique combined with the pressure at the solid wall to track the motion of the one-way stop valve diaphragm in the connecting pipe, thereby better predicting the fuel transfer in the connecting pipe. The calculation covers the whole process of flight vehicle erection, standby, flight, pumping, and pressurization and provides the distribution of pressure in different fuel tanks and the fuel flow characteristics in the connecting pipe. The calculation results are consistent with the experimental results, which verifies the accuracy of the model. By calculating different working cases, the results show that the different states of the flight vehicle strongly affect the sloshing of the liquid in the fuel tank, the pressure distribution, and the opening and closing of the valves. The maximum mass flow rate through the three valves, pressure at the bottom of the tank, and pressure at the pumping port all increase after the pressurization in the fuel tank. The flow of fuel between different tanks can be increased by changing the structure of the connecting pipe, which affects the pressure at different locations in the tank and at the pumping port.