Rankine Vortex Suppression in Tanks with Conical Base: A Numerical Investigation

During draining of liquid propellants from propellant tanks of spacecraft rocket engines, air core vortex can be formed and this can result in blockage of drain port. Supply of required amount of fuel (propellant) to the engine may get adversely affected due to this, which can lead to poor engine performance. Hence, vortex suppression is a practical necessity in this space application and this forms the motivation for the current study. This paper deals with numerical studies on vortex air core formation during liquid draining from a cylindrical tank with conical base. Ansys Fluent was used for the numerical simulation. A liquid column contained in a cylindrical tank with conical bottom was rotated and then drained through a centrally located drain port situated at the base of the tank. The angle of the tank base and drain port diameters were varied over a broad range to attempt vortex suppression. Results indicate that vortex is more suppressed at higher values of base angle. Suppression achieved by employing a conical base is the major and novel contribution of this study. The suppression strategy discussed in the current study has applications in aerospace engineering such as liquid propulsion systems.