Author : N Sreekanth 1
Date of Publication :30th December 2017
Abstract: Liquid Propellant servicing of any propulsion systems is very critical due to hazardous nature of fluids and safety involved in handling. For any successful launch mission, fluid servicing, especially with respect to cryogenic servicing is very critical due to complex preparation, chilling, filling, and pre-launch operations involved. During fluid servicing of launch vehicles, critical process parameters such as pressure, temperature and flow rate are required to be attained within the specified tolerance limits to meet launch lift-off requirements. Cryogenic propellants have a very low boiling point and low latent heat of evaporation due to which pressure and flow control is very challenging. Hence, it is very important to predict the actual performance characteristics of the flow control valve for different stroke lengths and for different plug profiles and select the optimum plug to suit to process conditions. Flow coefficient Cv is of primary interest in predicting the valve performance during its operation. This paper attempts to predict performance characteristics of a cryogenic globe valve used for flow control of Liquid Oxygen flow using computational fluid dynamics (CFD). Valves having different valve capacity factors were considered for evaluation of performance characteristics and derived the pressure and velocity contours inside the valve. The performance of this control valve installed in the Cryogenic fluid circuits have been independently evaluated for various process flow conditions and suitability of the valve has been verified for optimum flow conditions. The results of the computational analysis are found to be in close agreement with experimental tests.
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