Novel Design of Orifice Type Control Element for Mitigating Instabilities
Project Description
An orifice element is commonly used in liquid rocket engine test facilities to provide a large reduction in pressure over a very small distance in the piping system. Orifice elements are used in propellant lines, feed systems, plume suppression systems and steam ejector trains. While the orifice as a device is largely effective in stepping down pressure, it is also susceptible to a wake-vortex type instability and cavitation instability that propagate downstream and interact with other elements of the test facility resulting in structural vibration. In this proposal a new proprietary instability mitigation device has been developed that steps down the pressure, straightens the flow and suppresses all instability modes. The device is scalable and can be used for different mass flow rates and varying levels of de-pressurization conditions. It is relatively inexpensive to manufacture, easy to fabricate and install, and can be tailored to meet the performance requirements of a given facility. In Phase I, the device has been successfully demonstrated in a sub-scale cryogenic test facility. In Phase II the performance of the device will be calibrated for full-scale operation in a cryogenic test facility and a water test facility.
More »Anticipated Benefits
Orifice elements are ubiquitous in component test cells and test stands for liquid rocket engines. They are used in propellant lines, propellant conditioning systems, feed systems, water cooling systems in flame buckets and suppression systems to quench the flame. Instabilities that arise due to their operation compromise the safety of the test stands, increase loads on the test article, lead to premature shutdown of tests and cause costly delays. Such events have been observed at NASA SSC during J2-X testing, RS-25 testing, IPD LOX turbopump testing. The instability mitigation device developed in this program can suppress instabilities, substantially reduce risk and the likelihood of such events. The device can replace orifice elements in experimental/testing loops at NASA SSC/JSC/MSFC/KSC/GRC and Plumbrook. In doing so, this STTR program will directly aid NASA by supporting J2-X, RS-25, AJ-26 testing and the SLS and CCdev programs.
The commercial market for our product is very large and includes the commercial launch services industry as well as plant installations and industrial facilities that use extensive piping systems such as nuclear power generation, chemical process plants etc. The technology proposed here can play a critical and imminent role in addressing an important safety concern in pressurized water reactors where orifices are used in the emergency core cooling systems (ECCS) in conjunction with throttle valves.
Project Library
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Combustion Research and Flow Technology | Lead Organization | Industry | Pipersville, Pennsylvania |
Stennis Space Center
(SSC)
|
Supporting Organization | NASA Center | Stennis Space Center, Mississippi |
| University of Alabama in Huntsville (UAH) | Supporting Organization | Academia | Huntsville, Alabama |
Primary U.S. Work Locations
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Alabama
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Mississippi
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Pennsylvania
