John McCorquodale | University of New Orleans (original) (raw)

Papers by John McCorquodale

Hydraulic Engineering, 1994

The hydrodynamics of the Upper St. Marys River is simulated by a three dimensional steady state f... more The hydrodynamics of the Upper St. Marys River is simulated by a three dimensional steady state finite element model. The rigid lid and hydrostatic pressure assumptions are used in the development of the model. The model is designed to study wind induced current circulation in large bodies of water. Some of the model features include the use of upwinding finite element, modifications to allow for bottom slip and inflows/outflows at the boundaries. The model uses triangle elements which can accurately represent the geometry of the study area. Due to its quick computation speed for current circulation dynamics under different wind and inflow/outflows conditions, a fine grid discretization is used on the Upper St. Marys River. The model was calibrated and verified using aerial photographs of the area and as well as current meter data from the U.S. Army Corps of Engineers, the Ontario Ministry of the Environment and from the firm of Integrated Exploration Limited.

$Research paper thumbnail of A fractional two-step implicit algorithm using curvilinear collected grids$

International Journal for Numerical Methods in Fluids, 2006

Journal of Hydraulic Engineering, Feb 1, 1994

Shop ASCE; MyASCE; Donate Now; Contact Us; About Civil Engineering; About ASCE. ASCE Join Now. Kn... more Shop ASCE; MyASCE; Donate Now; Contact Us; About Civil Engineering; About ASCE. ASCE Join Now. Knowledge & Learning: Books & Journals; CE Body of Knowledge; Certification; Codes & Standards; Conferences; Continuing ...

Journal of Environmental Engineering, Oct 1, 1988

An experimental study is reported of the effect of geometry on the hydraulics of rectangular sett... more An experimental study is reported of the effect of geometry on the hydraulics of rectangular settling tanks in the absence of density currents and suspended solids. A scale model that could be operated under various flows and geometric conditions was used in the investigation, and 13 configurations were tested using a laser-Doppler anemometer to measure the mean and rms velocities throughout th tank. The effects of tank length, inlet opening, and flow rate on velocity and turbulence distribution within the tank were studied. Flow patterns were obtained that showed the size of eddies, extent of the potential core, and the growth of the boundary layer. The energy balance was investigated on the basis of the measured velocities and depths. Mean kinetic energy and turbulent kinetic energy values were estimated integrating the mean velocity and rms profiles. All experiments were run with constant fluid density.

Canadian Journal of Civil Engineering, Dec 1, 1988

Many urban beaches on fresh water lakes and rivers face closure during peak summer periods due to... more Many urban beaches on fresh water lakes and rivers face closure during peak summer periods due to dangerous concentrations of fecal coliforms and other waterborne contaminants. One such example is the Lake Erie Metro Park which is located approximately 22 km (14 miles) downriver of Detroit, Michigan, and Windsor, Ontario, at the mouth of the Detroit River.N.K. Becker &amp;amp;amp;amp;amp; Associates Ltd. was retained in 1985 to research and develop a functional design for a swim basin that will be formed by cordoning off an area of the Detroit River with a breakwater. A unique feature of this breakwater is that it is being designed to filter water from the Detroit River to the extent required for safe swimming. When it is constructed in 1988, it will be capable of accommodating approximately 1500 swimmers.Extensive hydraulic model studies were carried out at the universities of Windsor and Michigan to research and develop a functional design for this facility. The methodology used to develop the design concepts for this swim basin as well as the results of the testing program are described in this paper. Key words: fecal coliforms, swim basin, sand filter, breakwater, hydraulic model, beach, circulation, waves, water deficit, precast concrete cylinders.

In this study, a numerical model of a circular clarifier was applied to reveal the effects of the... more In this study, a numerical model of a circular clarifier was applied to reveal the effects of the water depth on the hydraulic and removal efficiency. The velocity and solids concentration fields at different time steps during tank operation were predicted. The model accounts for a number of practical conditions including sludge storage, density variations, settling characteristics, turbulence, ratio of return activated sludge (RAS) withdraw and tank geometry variations at full scale.

Journal of Environmental Engineering, Aug 1, 1984

CRC Press eBooks, Jan 18, 2018

Journal of waterway, port, coastal, and ocean engineering, Sep 1, 1999

ABSTRACT To evaluate ex situ contaminated sediment remediation alternatives, an equation or algor... more ABSTRACT To evaluate ex situ contaminated sediment remediation alternatives, an equation or algorithm for estimating the costs of environmental dredging is required. Simple estimators exist in which the total dredging cost is based on the volume of material dredged. Unfortunately, these empirical estimators cannot accurately predict the cost of an environmental dredging project when production rates are slower than normal. An equation was developed for estimating the costs of hydraulic dredging that contains variables to accommodate the lower production rate of environmental dredging and empirical cost coefficients that were derived from the actual costs of 18 navigational dredging projects in the U.S. and Canadian Great Lakes. A similar equation was developed for mechanical dredging based on 20 Great Lakes dredging projects. The sensitivity of the total dredging cost predicted by these equations with respect to the input parameters was determined. The cost predictions of these equations compared favorably with those of the simple empirical estimators for navigational dredging projects.

Hydraulic Engineering, 1987

International Journal for Numerical Methods in Fluids, Nov 15, 1993

Journal of Hydraulic Engineering, Oct 1, 1992

ABSTRACT A mathematical model for predicting the velocity field and suspended solids transport in... more ABSTRACT A mathematical model for predicting the velocity field and suspended solids transport in secondary rectangular settling tanks is presented. The model is applied to investigate the effects of density stratification on the hydrodynamics in the settling tank, such as the behavior of the bottom current and surface return flow and solids concentration distribution. The model can be used to simulate the so-called density waterfall phenomenon at the front end of the settling tank. With the application of a double exponential relationship to describe the settling process of suspended solids with nonuniform particle sizes, the simulations of the solids concentration distribution in the low-concentration environment can be significantly improved. By comparing the predictions with field measurements, this model is verified and generally good agreement is obtained.

Journal of Environmental Engineering, Mar 1, 1992

ABSTRACT A drift-flux formulation that accounts for multiple bubble interactions is applied to de... more ABSTRACT A drift-flux formulation that accounts for multiple bubble interactions is applied to describe the mean water velocity, air fraction, and plume growth for a vertical air diffuser plume that is bound on one side. A coarse-bubble line-diffuser source in a rectangular mixing tank is considered. Physical velocity and plume width measurements are used to calibrate the numerical model. The model is shown to be sensitive to the initial plume width and the entrainment coefficient. A dimen-sionless equation for the ambient water velocity at the outer edge of the plume is developed from physical measurements. The water velocity and air fraction are assumed to be uniform over the plume width. Four ordinary differential equations are developed and solved simultaneously to obtain the changes in significant plume variables with fluid depth. To reproduce the observed plume characteristics, the entrainment coefficient was 30-60% higher than the single-phase jet entrainment coefficient. The effect of the wall friction was minor for depths less than 1 m.

Canadian Journal of Civil Engineering, Sep 1, 1985

A numerical model to simulate the performance of both rectangular and circular primary clarifiers... more A numerical model to simulate the performance of both rectangular and circular primary clarifiers is presented. The proposed model is restricted to those mean steady flows that are isothermal, of neutral density, low in solids concentration, and nearly two-dimensional.The strip integral technique is used to reduce the partial differential equations of continuity, momentum, and mass transport to a set of ordinary differential equations. The resulting set of equations is numerically integrated using a fifth-order, Runge–Kutta method.The full numerical model contains a hydrodynamic submodel and a transport submodel. The hydrodynamic submodel predicts the velocity field and dispersion characteristics within the clarifier, which are prerequisite for the transport submodel.The model, as presented here, was used to simulate the circular tanks used in the cities of Windsor, Ontario and Waterloo, Ontario. The predicted concentration profiles and removal efficiency were in good agreement with the measured values. Key words: numerical model, primary clarifiers, strip integral technique, transport model, concentration profiles, removal efficiency.

Journal of Environmental Engineering, Dec 1, 1995

Heavy-density currents occur when the inflow is denser than the ambient fluids in a basin. These ... more Heavy-density currents occur when the inflow is denser than the ambient fluids in a basin. These currents exist in most secondary sedimentation basins. This paper investigates the internal flow regimes associated with the density currents due to cold influent entering circular clarifiers. The experimental studies included flow with unsteady influent temperature under different conditions of geometry, momentum, and negative buoyancy. Velocity and temperature of different flow regimes were measured throughout the basin. The flow phenomena progressed through a sequence of density flow regimes: the denser wall jet, internal hydraulic jump, rebound at the gate, and stratification. The data were analyzed to determine the characteristic depths, velocities, and isotherms for the radial density currents in a basin. This study shows that circular tanks subject to variable influent temperatures (or concentrations) experience internal surges in the form of moving hydraulic jumps. Depending on the tank geometry, this phenomenon could result in degraded performance of clarifiers during transient density events.

Canadian Journal of Civil Engineering, Jun 1, 1984

The strip integral method has been applied to a typical restricted inlet circular primary clarifi... more The strip integral method has been applied to a typical restricted inlet circular primary clarifier, in order to simulate the flow pattern and dispersion characteristics of the flow. This method assumes a dominant flow direction and with the use of velocity shape functions reduces the equations of motion and continuity to a set of simultaneous ordinary equations. Three shapes were chosen, corresponding to the boundary layer, the potential core, and the free mixing and recirculation zone. A Runge–Kutta method was used to integrate the set of ordinary differential equations. A standard finite element method was used in the withdrawal zone. The numerical predictions compared favorably with experimental velocity distributions obtained in a physical model of circular sedimentation tanks. The model is restricted to circular primary clarifiers of discrete suspension with low concentration operating at neutral density environment.The model was used to predict the velocity and dispersion characteristics of the circular tanks used at the West Windsor Pollution Control Plant, Windsor, Ontario.

Journal of Great Lakes Research, 1985

... CLAIR Kamal A. Ibrahim and John A. McCorquodale Great Lakes Institute University of Windsor W... more ... CLAIR Kamal A. Ibrahim and John A. McCorquodale Great Lakes Institute University of Windsor Windsor, Ontario N9B 3P4 ABSTRACT ... surface boundary conditions are: vertical it is possible to calibrate the model using field measurements as indicated by Cheng and Tung (1970 ...

Journal of Hydraulic Research, Sep 1, 1992

Local scour downstream of an apron with a swept-out hydraulic jump is shown to develop very rapid... more Local scour downstream of an apron with a swept-out hydraulic jump is shown to develop very rapidly, that is in less than 1% of the time to reach the ultimate scour depth. The short-term scour although not as deep as the long-term scour, occurs much closer to the apron. The limiting short-term scour depth is found to be related to

Canadian Journal of Civil Engineering, Jun 1, 1992

A numerical model has been developed to predict the velocity distribution and the concentration d... more A numerical model has been developed to predict the velocity distribution and the concentration distribution for a nonuniform flocculated particle suspension for turbulent density stratified flow in secondary clarifiers. This model consists of a set of conservation equations for fluid mass and momentum and sediment concentration as well as a relationship for solids settling velocity. The turbulent stresses are calculated using the eddy-viscosity concept and the k-ε turbulence model. Since the strong local numerical instabilities near the reaction baffle lip, where the low-solids concentration surface return flow joins the high solids concentration bottom current, was successfully overcome in the iterative solution procedure, the calculation zone in this investigation can be extended to take into account the inlet zone of the clarifier. The model gave a satisfactory description of the influence of the density variations on the hydraulic regime and the solids concentration distribution in the clarifier. A good agreement was obtained between the experimental data and the numerical simulation. Key words: clarifier, numerical model, density stratification, turbulence.

Journal of Hydraulic Engineering, May 1, 1997

... The new model has been applied to several problems including pure convection of a sharp step ... more ... The new model has been applied to several problems including pure convection of a sharp step profile, side discharge into an open channel, flow in a meanderingchannel, and flow in a Parshall flume with supercritical outflow. ...