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|Title:||Numerical Modeling of a Turbulent Plane Jet Impingement on a Solid Wall|
|Department / Program:||Civil Engineering|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Turbulent jet flows constitute a common problem for engineers. Owing to self-preservation in nature, a submerged jet has been well solved by the zero-equation turbulence model. However, in practice, the flow field is often confined by side walls or normal walls. Near those solid boundaries, flow situations depend highly on the impingement geometries. Therefore, it is almost impossible for engineers to labor through all experimental investigations of jet impingement on a case by case basis. This fact results in the necessity for an alternative in the study of jet impingement problems. In this study, the major effort was concentrated on a turbulence model of a plane jet impingement on a solid wall. Consequently, while using the same numerical scheme, different jet impingement geometries can be expressed as different boundary conditions.
In the present study, the two-equation, K-(ELEM), turbulence model combined with the continuity equation and the transport equation of vorticity is adopted to solve a plane jet impingement problem. Predictions of this model on a normal plane jet impingement include flow patterns of velocity, stream function, vorticity, turbulent kinetic energy, turbulent dissipation rate, eddy viscosity, pressure and shear stress. It has been found that the best prediction can be achieved when the wall Reynolds numbers fall within the range 100-150. In addition, an examination of the constant eddy viscosity in a normal plane jet impingement problem is also performed. It confirms that the role of eddy viscosity is mainly related to the diffusion process. With economic constraints, some preliminary work was also performed on an oblique plane jet impingement. This resulted in useful recommendations for future computation modeling.
As a result of the present study, the two-equation, K-(ELEM) turbulence model is judged to be applicable for the prediction of a plane submerged jet and a normal plane impinging jet on a solid wall. The particular handling of wall boundary values by using the wall function and the law of the wall, the introduction of a plane turbulent jet profile to the computational domain by extending Tollmein's solution (1926) and the use of the finite difference scheme of control volume and upwind method should provide very valuable information for practical purposes. Further studies associated with a free jet or an impinging jet can be developed from the conclusions and results of this study.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.
|Date Available in IDEALS:||2014-12-15|
This item appears in the following Collection(s)
Dissertations and Theses - Civil and Environmental Engineering
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois