Skip to the content

Numerical modelling of jet-forced circulation in reservoirs using boundary-fitted coordinate systems.

Barber, RW 1990, Numerical modelling of jet-forced circulation in reservoirs using boundary-fitted coordinate systems. , PhD thesis, Salford : University of Salford.

[img] PDF
Restricted to Repository staff only until 01 January 2015.

Download (10MB) | Request a copy

    Abstract

    Throughout the past decade, interest has grown in the use of boundary-fitted coordinate systems in many areas of computational fluid dynamics. The boundary-fitted technique provides an exact method of implementing finite-difference numerical schemes in curved flow geometries and offers an alternative solution procedure to the finite-element method. The unavoidable large bandwidth of the global stiffness matrix, employed in finite-element algorithms, means that they are computationally less efficient than corresponding finite-difference schemes. As a consequence, the boundary-fitted method offers a more efficient process for solving partial differential flow equations in awkwardly shaped regions. This thesis describes a versatile finite-difference numerical scheme for the solution of the shallow water equations on arbitrary boundary-fitted non-orthogonal curvilinear grids. The model is capable of simulating flows in irregular geometries typically encountered in river basin management. Validation tests have been conducted against the severe condition of jet-forced flow in a circular reservoir with vertical side walls, where initial reflections of free surface waves pose major problems in achieving a stable solution. Furthermore, the validation exercises have been designed to test the computer model for artificial diffusion which may be a consequence of the numerical scheme adopted to stabilise the shallow water equations. The thesis also describes two subsidiary numerical studies of jet-forced recirculating flow in circular cylinders. The first of these implements a Biot-Savart discrete vortex method for simulating the vorticity in the shear layers of the inflow jet, whereas the second employs a stream function/vorticity-transport finite-difference procedure for solving the two-dimensional Navier-Stokes equations on a distorted orthogonal polar mesh. Although the predictions from the stream function/vorticity-transport model are confined to low Reynolds number flows, they provide a valuable set of benchmark velocity fields which are used to confirm the validity of the boundary-fitted shallow water equation solver.

    Item Type: Thesis (PhD)
    Contributors: Borthwick, AGL(Supervisor)
    Schools: Colleges and Schools > College of Science & Technology > School of Environment and Life Sciences > Ecosystems and Environment Research Centre
    Colleges and Schools > College of Science & Technology > School of Computing, Science and Engineering
    Depositing User: Institutional Repository
    Date Deposited: 03 Oct 2012 14:34
    Last Modified: 19 Feb 2014 11:05
    URI: http://usir.salford.ac.uk/id/eprint/26561

    Actions (login required)

    Edit record (repository staff only)

    Downloads per month over past year

    View more statistics