A numerical framework for analysis of complex valve systems supports testing of propulsive systems by simulating key valve and control system components in the test loop. In particular, it is designed to enhance the analysis capability in terms of identifying system transients and quantifying the valve response to these transients. This system has analysis capability for simulating valve motion in complex systems operating in diverse flow regimes ranging from compressible gases to cryogenic liquids. A key feature is the hybrid, unstructured framework with sub-models for grid movement and phase change including cryogenic cavitations.

The multi-element unstructured framework offers improved predictions of valve performance characteristics under steady conditions for structurally complex valves such as pressure regulator valve. Unsteady simulations of valve motion using this computational approach have been carried out for various valves in operation at Stennis Space Center such as the splitbody valve and the 10-in. (≈25.4-cm) LOX (liquid oxygen) valve and the 4-in. (≈10 cm) Y-pattern valve (liquid nitrogen). Such simulations make use of variable grid topologies, thereby permitting solution accuracy and resolving important flow physics in the seat region of the moving valve.

An advantage to

this software includes possible reduction in testing costs incurred due to disruptions relating to unexpected flow transients or functioning of valve/flow control systems. Prediction of the flow anomalies leading to system vibrations, flow resonance, and valve stall can help in valve scheduling and significantly reduce the need for activation tests. This framework has been evaluated for its ability to predict performance metrics like flow coefficient for cavitating venturis and valve coefficient curves, and could be a valuable tool in predicting and understanding anomalous behavior of system components at rocket propulsion testing and design sites.

This program was written by Vineet Ahuja, Ashvin Hosangadi, Jeremy Shipman, Peter Cavallo, and Sanford Dash of Combustion Research and Flow Technology (CRAFT), Inc. for Stennis Space Center.

In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:

Dr. Vineet Ahuja

Combustion Research and Flow Technology

(CRAFT Tech), Inc.

6210 Keller's Church Road

Pipersville, PA 18947-1020

Phone No.: (215) 766-1520

Fax: (215) 766-1524

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Refer to SSC-00245, volume and number of this NASA Tech Briefs issue, and the page number.


NASA Tech Briefs Magazine

This article first appeared in the September, 2007 issue of NASA Tech Briefs Magazine.

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