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Transient Three-Dimensional Analysis of Nozzle Side Load in Regeneratively Cooled EnginesThree-dimensional numerical investigations on the start-up side load physics for a regeneratively cooled, high-aspect-ratio nozzle were performed. The objectives of this study are to identify the three-dimensional side load physics and to compute the associated aerodynamic side load using an anchored computational methodology. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics formulation, and a transient inlet condition based on an engine system simulation. Computations were performed for both the adiabatic and cooled walls in order to understand the effect of boundary conditions. Finite-rate chemistry was used throughout the study so that combustion effect is always included. The results show that three types of shock evolution are responsible for side loads: generation of combustion wave; transitions among free-shock separation, restricted-shock separation, and simultaneous free-shock and restricted shock separations; along with oscillation of shocks across the lip. Wall boundary conditions drastically affect the computed side load physics: the adiabatic nozzle prefers free-shock separation while the cooled nozzle favors restricted-shock separation, resulting in higher peak side load for the cooled nozzle than that of the adiabatic nozzle. By comparing the computed physics with those of test observations, it is concluded that cooled wall is a more realistic boundary condition, and the oscillation of the restricted-shock separation flow pattern across the lip along with its associated tangential shock motion are the dominant side load physics for a regeneratively cooled, high aspect-ratio rocket engine.
Document ID
20050212149
Acquisition Source
Marshall Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Wang, Ten-See (NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
September 7, 2013
Publication Date
March 29, 2005
Subject Category
Spacecraft Propulsion And Power
Report/Patent Number
AIAA Paper 2005-3942
Meeting Information
Meeting: 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
Location: Tucson, AZ
Country: United States
Start Date: July 10, 2005
End Date: July 13, 2005
Sponsors: American Inst. of Aeronautics and Astronautics, American Society of Mechanical Engineers, Society of Automotive Engineers, Inc., American Society for Electrical Engineers
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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