Date of Award
Master of Science (MS)
In this thesis, the whole materials can be divided in to three parts. The first part focused on single round jet impingement. The convention air jet impingement on ground surface was compared to air jet impingement on water surface in the range of Mach number from 0 to 0.3. Currently the studies on round jet impingement on water surface are very few. The goal of this research is to study the difference of aerodynamics and flow physics between air jet impinging on water surface and ground surface at different low Mach number and Non-dimensional height. The incompressible Reynolds-Averaged Navier-Stokes equations with K-epsilon (k-ε) turbulence model are solved using the commercial CFD solver ANSYS FLUENT. For jet exit near the flat ground surface and water surface, some interesting differences in flow phenomenon are obtained due to that ground is rigid and water is squashy. The second part focused on twin water jet impingement on each other in a water tank. For the complex flow phenomenon including relatively low-pressure region, flow curvature and backflow vortex are successfully captured by numerical methods. The twin jet after impingement on each other will combine as one single jet. Compared to the traditional study on the main symmetry plane (2-D dominated), there is another symmetry plane where flow phenomenon can be analyzed by a typical 3-D relieving effect. The third part focuses on a 3-D helicopter rotor blade with ground effect. The result firstly demonstrated that modern technology has ability to make a well-matched CFD result. Then it explored changing pattern of the flow field with different angles of attack and non-dimensional heights when rotor being close to ground surface.
Ramesh Agarwal, Chair David Peters Quanzhong Liu