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An Experimental Study Of Flow Control Techniques On A Multi-Element Airfoil, Ira James Walker
An Experimental Study Of Flow Control Techniques On A Multi-Element Airfoil, Ira James Walker
Mechanical & Aerospace Engineering Theses & Dissertations
The results of a wind tunnel experiment are reported, which investigated two different flow control techniques that demonstrated the potential of increasing the lift coefficient on a multi-element airfoil. The data also indicated that boundary-layer separation on the trailing-edge flap could be reduced significantly. Results of the investigation revealed that for some test conditions an increased amount of suction occurred on the upper surface of the main element where the flow was attached. One of the techniques that was tested in this investigation involved the use of a pair of piezoelectric devices attached to the model to provide oscillatory motion …
Dynamic Unstructured Method For Prescribed And Aerodynamically Determined Relative Moving Boundary Problems, Kamakhya Prasad Singh
Dynamic Unstructured Method For Prescribed And Aerodynamically Determined Relative Moving Boundary Problems, Kamakhya Prasad Singh
Mechanical & Aerospace Engineering Theses & Dissertations
A new methodology is developed to simulate unsteady flows about prescribed and aerodynamically determined moving boundary problems. The method couples the fluid dynamics and rigid-body dynamics equations to capture the time-dependent interference between stationary and moving boundaries. The unsteady, compressible, inviscid (Euler) equations are solved on dynamic, unstructured grids by an explicit, finite-volume, upwind method. For efficiency, the grid adaptation is performed within a window around the moving object. The Eulerian equations of the rigid-body dynamics are solved by a Runge-Kutta method in a non-inertial frame of reference. The two-dimensional flow solver is validated by computing the flow past a …
Aerodynamic Design Optimization With Consistently Discrete Sensitivity Derivatives Via The Incremental Iterative Method, Vamshi M. Korivi
Aerodynamic Design Optimization With Consistently Discrete Sensitivity Derivatives Via The Incremental Iterative Method, Vamshi M. Korivi
Mechanical & Aerospace Engineering Theses & Dissertations
In this study which involves advanced fluid-flow codes, an incremental iterative formulation (also known as the "delta" or "correction" form), together with the well-known spatially split approximate-factorization algorithm, is presented for solving the large, sparse systems of linear equations that are associated with aerodynamic sensitivity analysis. For the smaller two dimensional problems, a direct method can be applied to solve these linear equations in either the standard or the incremental form, in which case the two are equivalent. However, iterative methods are needed for larger two-dimensional and three dimensional applications because direct methods require more computer memory than is currently …