Summary
This thesis
investigated the
design of a flow diffuser and conditioner
for the new circular wave and tidal tank due to be built at Edinburgh
University.
The aim was to use a diffuser to produce a fully developed velocity
profile over the
shortest possible
distance. A diffuser is a specially designed expansion in a pipe or channel which changes the speed the flow. This property of the device can be used to redistribute velocity of the flow as required.
The flow in the diffuser was anticipated to be highly turbulent and the use of a flow straightener, of various designs, was considered. A number of constraints on the dimensions of the tank prevented the use of a conventional diffuser so a novel design
was developed instead. Using computational fluid mechanics the design was developed inexpensively. Validation and verification were performed using analytical calculations and potential flow theory. It was shown that these methods provided good agreement within the diffuser. Beyond the diffuser, potential flow theory predicted a constant velocity profile. It was reasoned that this is due to a fundamental flaw in potential flow theory in modelling the far field flow characteristics.
The unique design presented in the report stems from the unconventional tank required and the sparse documentation available on diffuser design. This thesis adds to the literature in the field of wave and tidal tank diffuser design.
distance. A diffuser is a specially designed expansion in a pipe or channel which changes the speed the flow. This property of the device can be used to redistribute velocity of the flow as required.
The flow in the diffuser was anticipated to be highly turbulent and the use of a flow straightener, of various designs, was considered. A number of constraints on the dimensions of the tank prevented the use of a conventional diffuser so a novel design
was developed instead. Using computational fluid mechanics the design was developed inexpensively. Validation and verification were performed using analytical calculations and potential flow theory. It was shown that these methods provided good agreement within the diffuser. Beyond the diffuser, potential flow theory predicted a constant velocity profile. It was reasoned that this is due to a fundamental flaw in potential flow theory in modelling the far field flow characteristics.
The unique design presented in the report stems from the unconventional tank required and the sparse documentation available on diffuser design. This thesis adds to the literature in the field of wave and tidal tank diffuser design.
Introduction
Details of the project are
available in two formats. A copy of the thesis
can be downloaded. Alternatively a fun interactive approach is to use
the image maps on this site. To begin with the diffuser design problem
and the context is explained by clicking on the various links
incoporated into the schematic below. Links to the other stages
of design are embeded in the flow chart below this diagram.
Click on the tank image map for a fun way to learn about the wave and tidal tank
