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Numerical Modeling of Cavitating Venturi: A Flow Control Element of Propulsion SystemIn a propulsion system, the propellant flow and mixture ratio could be controlled either by variable area flow control valves or by passive flow control elements such as cavitating venturies. Cavitating venturies maintain constant propellant flowrate for fixed inlet conditions (pressure and temperature) and wide range of outlet pressures, thereby maintain constant, engine thrust and mixture ratio. The flowrate through the venturi reaches a constant value and becomes independent of outlet pressure when the pressure at throat becomes equal to vapor pressure. In order to develop a numerical model of propulsion system, it is necessary to model cavitating venturies in propellant feed systems. This paper presents a finite volume model of flow network of a cavitating venturi. The venturi was discretized into a number of control volumes and mass, momentum and energy conservation equations in each control volume are simultaneously solved to calculate one-dimensional pressure, density, and flowrate and temperature distribution. The numerical model predicts cavitations at the throat when outlet pressure was gradually reduced. Once cavitation starts, with further reduction of downstream pressure, no change in flowrate is found. The numerical predictions have been compared with test data and empirical equation based on Bernoulli's equation.
Document ID
20030001043
Document Type
Conference Paper
Authors
Majumdar, Alok (NASA Marshall Space Flight Center Huntsville, AL United States)
Saxon, Jeff
Date Acquired
August 21, 2013
Publication Date
January 1, 2002
Subject Category
Fluid Mechanics and Thermodynamics
Meeting Information
Thermal and Fluids Analysis Workshop(Houston, TX)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.