Performance Evaluation of Degas Tank

This paper presents the free surface behaviour of liquid while degas tank bottle is in service. The liquid in the degas tank is subjected to exceed the mean line in the service and the fluid levels in all chambers varies as there is continuous movement and sloshing in the fluid. The objective of this work is to optimize the baffle design such that the fluid level in the tank does not exceed the mean line in service and fluid in the all chambers will be maintained at same level. The scope of work is also to enhance the tank baffles which will further dampen the fluid sloshing and the fluid de-aeration should be done effectively to avoid any possible structural damage. The simulation of liquid free surface behaviour is done using commercial CFD software. A numerical model is developed based on Volume of Fluid (VOF) technique to track the free surface motion of liquid. The explicit time discretization scheme is employed to solve the volume fraction equation. From the numerical analysis, amplitude of free surface elevation and slope of free surface are predicted. Experiments are carried out with transparent fuel tank, fabricated using glass fiber. The CFD simulation results are then validated with the test results and are pretty much similar. This methodology of degas tank design has been further optimized for better performance of the tank.