The problem studied is the laminar flow over inclined, finite flat plates for moderately high Reynolds numbers in two and three dimensions. There are only few prior analyses, mainly for two dimensional flow, for this problem, and thus it was decided that it was worthwhile to study it now in great detail. The full Navier-Stokes equations were solved using a weak Galerkin formulation for the Finite Element Method with the pressure determined by a penalty approach. The influence of grid resolution, boundary conditions and size of the domain was studied. The true nature of the flow for different Reynolds numbers was also examined through steady and unsteady simulations of the two dimensional cases for 6600 â ¤ ReL â ¤18000. Results for the three dimensional flow over square plates at two angles of attack, a = 3.0 and 8.0 degrees for ReL = 100 are presented. The results are given in terms of skin friction and pressure coefficient variations along with flowfield visualization. Comparison between the two dimensional and three dimensional flow indicates the influence of the third coordinate to the flow. The analysis indicated that the two dimensional flow over a finite thick plate at 3.0 degrees angle of attack is steady up to Re = 12000. The solution for the upper surface is strongly influenced by the presence of a recirculation bubble at the leading edge. The slope of the lift curve for the 2D viscous flow is less than 2Ï , the result predicted by the thin wing theory. The solution for the three dimensional flow is strongly influenced by the the existence of the tip vortices. The slope of the lift curve for the 3D viscous flow is less than the one corresponding to the 2D flow. In addition, the effect of the aspect ratio on the lift does not agree with the inviscid lifting line theory prediction. / Master of Science

The ever increasing traffic congestion being experienced on urban freeways has caused attention to be focused on methods for improving traffic operations on these facilities. The reduction or elimination of freeway congestion can be handled in two basic ways: 1) by increasing the freeway's capacity defined as the number of vehicles per unit time that can pass a given point in one lane of the freeway multiplied by the number of lanes on the freeway, or 2) by decreasing the traffic loads imposed on these freeways. Monumental costs and adverse public relations are involved in the construction of either new freeways or additional lanes in urban areas to increase freeway capacity. Due to these factors, the move in recent years has been toward decreasing traffic loads to accomplish the goals of reduction or elimination of freeway congestion. In an effort to combat the freeway congestion, traffic researchers have devoted much time and effort to the theoretical and practical aspects of systems in which controlled access is utilized to prevent or reduce congestion caused by traffic demands in excess of freeway operational capacity. Such systems perform the function of 'freeway surveillance and control'. An important aspect of these systems is the control mechanism used for the regulation of the ramp traffic to the freeway. This topic of ramp metering is the subject of this report.

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Typescript (photocopy). / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1979 H43 / Master of Science

Call number: LD2668 .T4 1985 T47 / Master of Science

A finite element numerical model is developed for the modeling of coupled surface-water flow and ground-water flow. The mathematical treatment of subsurface flows follows the confined aquifer theory or the classical Dupuit approximation for unconfined aquifers whereas surface-water flows are treated with the kinematic wave approximation for open channel flow. A detailed discussion of the standard approaches to represent the coupling term is provided. In this work, a mathematical expression similar to Ohm's law is used to simulate the interacting term between the two major hydrological components. Contrary to the standard approach, the coupling term is incorporated through a boundary flux integral that arises naturally in the weak form of the governing equations rather than through a source term. It is found that in some cases, a branch cut needs to be introduced along the internal boundary representing the stream in order to define a simply connected domain, which is an essential requirement in the derivation of the weak form of the ground-water flow equation. The fast time scale characteristic of surface-water flows and the slow time scale characteristic of ground-water flows are clearly established, leading to the definition of three dimensionless parameters, namely, a Peclet number that inherits the disparity between both time scales, a flow number that relates the pumping rate and the streamflow, and a Biot number that relates the conductance at the river-aquifer interface to the aquifer conductance. The model, implemented in the Bill Williams River Basin, reproduces the observed streamflow patterns and the ground-water flow patterns. Fairly good results are obtained using multiple time steps in the simulation process.