Study Of Capillary Flow In Spherical Tank Interior Corner Under Microgravity

As an important part of the aviation engine,the main function of the Liquid propellant tank is to supply pure liquid for the spacecraft.Under microgravity environment where B0 is 1,the flow of the liquid is influenced by a lot of effects in which the surface tension has the greatest impact.The effect caused by the surface tension will lead the nature of liquid capillary flow to change a lot,which requires tank to have a higher fluid management capacity and reliability.Therefore,the design and optimization for tanks has become a key link for the technology of spacecraft on-orbit refueling.By building a virtual internal angle,asymmetric internal angle is transformed into symmetrical interior angle.Based on the Navies-Stokes equations,This article established no-linear equations for the liquid capillary flow in the spherical tank internal angle.By solving the steady-state solution of the liquid level height,we can get the expression of the liquid length and the initial cross-sectional flow.After solving the mathematical model of virtual interior angles,we conclude that there is an inverse relationship between the curvature radius of liquid level and the breadth of the guide plate outside and there is a proportional relationship between the size of the interior angle and the breadth of the guide plate outside.Finally,this article confirm the most appropriate number of deflector by the initial cross-sectional flow and the flow efficiency.And then,this article optimize the structure of the outer deflector by calculating the length of the liquid which contacts with the outer deflector so that we can reduce tank’s weight and improve tank’s work efficiency.Using FLOW-3D software to simulate tank model,we can explore the influence exerted by the working medium,tank material,initial liquid height and cross-sectional area on the capillary flow.The simulation study shows that reducing the contact angle and increasing the initial cross-sectional area will make the capillary flow accelerated.And it also shows that absolute ethyl alcohol climbs faster than 10cs silicon oil.Using Surface Evolver software to analyze capillary flow of a spherical tank qualitatively,the simulation results can also prove that the law above is correct.Simultaneously,this article created a new method for researching capillary flow of spherical tank.