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Accession Number ADA564230
Title Freedrop Testing and CFD Simulation of Ice Models from a Cavity into Supersonic Flow.
Publication Date Sep 2012
Media Count 230p
Personal Author T. J. Flora
Abstract Weapon release at supersonic speeds from an internal bay is highly advantageous. For this reason, both experimental and numerical methods were used to investigate store separation from a cavity (L=D=4.5) into Mach 2.94 ow. The experiment used a piezoresistive pressure transducer, Schlieren and high- speed photography for data acquisition. The computational solution used the OVERFLOW solver. A sphere and a Mk-82, scaled to 1:20, were formed using frozen tap water. The sphere model was freedrop tested experimentally and computationally, while the sub-scale store shaped model was freedrop tested experimentally. The total pressure was varied to alter the dynamic response of the model. Computed spectra of pressure signals were in reasonable agreement with those measured experimentally, while the trajectory and dynamics of the CFD sphere release closely matched the experiment. Two sawtooth spoiler devices were tested for e ectiveness at high Mach numbers. Pressure measurements showed a detuning of the Rossiter tones but with an increase in the broadband levels. Furthermore, spoiler testing demonstrated the capability to enhance store separation. Mk-82 shapes were also tested, which proved that the experimental process can be used with representations of actual stores. Reducing the test pressure conditions to sub-atmospheric levels allowed sub-scale models to be accurately scaled in mass and moment of inertia using heavy Mach scaling laws.
Keywords Audio tones
Cavity flow
Cfd
Dynamic response
Dynamic scaling
External store separation
Free dropping
Freedrop testing
Frequency analysis
High speed photography
Numerical methods and procedures
Pressure measurement
Rossiter modes
Store separation
Supersonic flow

 
Source Agency Non Paid ADAS
NTIS Subject Category 46B - Fluid Mechanics
Corporate Author Air Force Inst. of Tech., Wright-Patterson AFB, OH. Graduate School of Engineering and Management.
Document Type Thesis
Title Note Msster's thesis.
NTIS Issue Number 1302
Contract Number N/A

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