Date of Award


Publication Type

Doctoral Thesis

Degree Name



Civil and Environmental Engineering


Engineering, Civil.




A numerical model of primary clarifiers performance, emphasizing the prediction of both the velocity field and the distribution of particulate concentration is presented in this dissertation. The model is restricted to those mean steady flows which are isothermal, neutral density, operating at low concentration and nearly two-dimensional. The simulation is for either rectangular or circular basins. The simulation requires a hydrodynamic submodel and a transport submodel. The hydrodynamic submodel employs the Strip Integral Method (SIM) to solve the governing differential equations of motion and continuity. This method is an improvement over the plug flow models in that it can reproduce the principle features of the flow such as the boundary layer and recirculation. It has an advantage over the finite element and the finite difference models since it requires relatively low computer storage and computational time. This is particularly important if the model is to be implemented on a micro-computer. The SIM assumes a dominant flow direction. Velocity shape functions are used to reduce the equations of motion and continuity to a set of simultaneous ordinary equations in terms of preselected parameters in the dominant independent variable. A modified mixing length approach was applied to obtain the turbulent shear in the mixing zone. The hydrodynamic submodel was calibrated using measured velocity distributions in physical models. The model was also verified by comparing its results with other tests that were not used in the calibration. The SIM was also used to solve the transport equation. The transport submodel was verified by comparing the results with similar work of other researchers. The model was used to simulate the primary clarifiers used at the cities of Windsor, and Sarnia, Ontario. The predicted removal efficiency agreed well with the measured values. As an application to the model, it was used to simulate the removal of non-uniform size discrete suspension. It was also used to improve the design of the inlet to the tank. The hydrodynamic submodel was used to modify Camp's theoretical solution for solids removal in turbulent flow. It was also used to simulate the internal flow structure of a submerged hydraulic jump. The computation time for the model was 50 to 65 secs CPU time on an IBM 3031.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1983 .A224. Source: Dissertation Abstracts International, Volume: 44-09, Section: B, page: 2838. Thesis (Ph.D.)--University of Windsor (Canada), 1983.