Conformal Propellant Tanks and Vane Design
Abstract
Current small satellite propellant tank design is driven by three factors: volume optimization, manufacturing capability, and propellant management. Conformal propellant tanks offer solutions to the design challenges of optimizing satellite volume and manufacturing costs. Conformal propellant tank designs that meet these challenges have unknown effects on propellant management. Compounding this uncertainty is the industry shift towards new green propellants with large contact angles. Improper propellant management can deliver gas to a thruster or leave propellant trapped away from the tank outlet while draining. Both scenarios reduce the lifespan of satellites. Stamping is one manufacturing process that can produce tanks that optimize volume and are relatively easy to manufacture. The effects of the stamping process on tank shape and propellant management is evaluated through testing four different tank geometries. The stamping process sometimes leaves behind a seam where two sides of a tank are joined together. A total of six tank and vane combinations are tested. One set of traditional tanks serve as a control. Three tanks tested share vane geometry and have different interiors to evaluate the effects of the stamping process on propellant management. The first tank has a smooth interior, the second has a seam at the joints and the third tank has a seam and ridges for increased stiffness. The last two tanks have an interior in the shape of an arc and have different vanes. The experiment is flown on the ZeroG airplane to test the tank and vane designs in a weightless environment. The experiment consists of a payload rack, eleven experimental pods and one power distribution pod. Each experimental pod is designed to be modular and independent from all other experimental pods. Each experimental pod hosts a camera, electrical box, second containment and fluid system with four tanks. The results of this study show no discernible difference could be observed between tanks with or without a seam from the stamping process. When ridges are added to a tank that are parallel to the contact line, liquid may not wick into the ridge if it is dry. If the ridge is wet the liquid spreads out on the surface of the tank further. The differences between propellant positioning for zero and nonzero contact angle fluids are discussed.
Degree
M.Sc.
Advisors
Collicott, Purdue University.
Subject Area
Design|Energy|Aerospace engineering|Industrial engineering
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