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Full-Text Articles in Engineering
Optimizing Design Parameters For Active Flow Control Boundary-Layer Fence Performance Enhancement On A Delta Wing, Nathan L. Tedder
Optimizing Design Parameters For Active Flow Control Boundary-Layer Fence Performance Enhancement On A Delta Wing, Nathan L. Tedder
Theses and Dissertations
Utilizing computational fluid dynamic (CFD) simulations, the presented study is able to further the investigation of replicating and improving upon the performance of a NACA 0012 cropped half-span delta-wing at high angles-of-attack with an active flow control fluidic fence via wall-normal, steady blowing from an optimized single chordwise slot located at z/b = 70%,. The data is generated using CREATE-AV Kestrel v10.1rc5 CFD software on the Department of Defense High Performance Computing systems. The flight regime is held constant at a Mach number of 0.18 and a Reynolds number (Re) of 5.0 x 105, based on the root …
Thermochemical Non-Equilibrium Models For Weakly Ionized Hypersonic Flows With Application To Slender-Body Wakes, Matthew P. Clarey
Thermochemical Non-Equilibrium Models For Weakly Ionized Hypersonic Flows With Application To Slender-Body Wakes, Matthew P. Clarey
Theses and Dissertations
The current resurgence of interest in hypersonic technologies has warranted an inquiry into the commonly employed thermochemical non-equilibrium models within computational fluid dynamic (CFD) simulations. Additionally, research has historically focused on forebody flowfields, while studies of the complex wake structure have remained elusive. Although the forebody is of significance for vehicle analysis, the wake presents many exploitative characteristics. This dissertation aimed to address these two deficits. First, two three-temperature non-equilibrium models were developed, increasing the fidelity of hypersonic solutions above that of the legacy two-temperature model. The models were then investigated via zero-dimensional simulations, to detail the non-equilibrium processes, and …
Freedrop Testing And Cfd Simulation Of Ice Models From A Cavity Into Supersonic Flow, Thomas J. Flora
Freedrop Testing And Cfd Simulation Of Ice Models From A Cavity Into Supersonic Flow, Thomas J. Flora
Theses and Dissertations
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 flow. 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 …
Cfd Analysis Of Experimental Wing And Winglet For Falconlaunch 8 And The Exfit Program, Benjamin P. Switzer
Cfd Analysis Of Experimental Wing And Winglet For Falconlaunch 8 And The Exfit Program, Benjamin P. Switzer
Theses and Dissertations
Reusable launch vehicles have many benefits over their expendable counterparts. These benefits range from cost reductions to increased functionality of the vehicles. Further research is required in the development of the technology necessary for reusable launch vehicles to come to fruition. The Air Force Institute of Technology’s future involvement in the ExFIT program will entail designing and testing of a new wing tip mounted vertical stabilizer in the hypersonic regime. One proposed venue for experimentation is to utilize the United States Air Force Academy’s FalconLAUNCH Program which annually designs, builds, and launches a sounding rocket capable of reaching hypersonic speeds. …
Comparative Study Of Aerodynamic Interference During Aft Dispense Of Munitions, Matthew G. Burkinshaw
Comparative Study Of Aerodynamic Interference During Aft Dispense Of Munitions, Matthew G. Burkinshaw
Theses and Dissertations
Based on forthcoming USAF needs, an investigation was launched to further the understanding of aft dispense of munitions in a high-speed environment. A computational fluid dynamics (CFD) study was performed followed by a wind tunnel experiment. The study consisted of a strut-mounted cone simulating a parent vehicle and a sting mounted cone-cylinder store situated directly behind the cone. The CFD modeled the test objects inside a supersonic wind tunnel in which the experiments took place. The CFD study consisted of evaluating a new strut designed to reduce asymmetry in the airflow aft of the cone. The CFD study also included …
Dynamic Aeroelastic Analysis Of Wing/Store Configurations, Gregory H. Parker
Dynamic Aeroelastic Analysis Of Wing/Store Configurations, Gregory H. Parker
Theses and Dissertations
Limit-cycle oscillation, or LCO, is an aeroelastic phenomenon characterized by limited amplitude, self-sustaining oscillations produced by fluid-structure interactions. In order to study this phenomenon, code was developed to interface a modal structural model with a commercial computational fluid dynamics program. LCO was simulated for a rectangular wing, referred to as the Goland+ wing. It was determined that the aerodynamic nonlinearity responsible for LCO in the Goland+ wing was the combination of strong trailing-edge and lambda shocks which periodically appear and disappear. This mechanism limited the flow of energy into the structure which quenched the growth of the flutter, resulting …