M.Ing. / This thesis considers in detail the applicability to hydro power systems of the theories of steady and unsteady flow in pipelines. In doing so.it highlights some of the shortcomings of these theories. An attempt is made by way of experimentation on a high pressure pipeline, to model some of the conditions which could occur in a full size future hydro power system. These experiments provide some quantitative data about the performance of some typical hydro power components such as pipes, orifices and valves, under steady and unsteady conditions. A computer program is included which was used to provide theoretical data to compare with the experimental results. The program was found to be limited in its capacity to provide accurate simulation of the experimental pipeline, but this was thought to be due to the pipeline not correctly modelling a hydro power system. Conclusions presented in this thesis will be of assistance to designers of future hydro power systems and to researchers continuing this work.

A mathematical model was developed for the rapid filling of an initially dry pipe. The pipe was assumed to be horizontal and to contain an orifice at the downstream end. The key elements of the model were the momentum equation governing the flow of the water, the thermodynamic equations for the compression and discharge of the entrapped air, and the equations for waterhammer resulting from the impact of the water with the orifice. A computer program of this model was then developed and tested. After initial testing, the model was used to examine the magnitudes of the pressures that could be produced from waterhammer and air compression for various lengths of pipe. The effects that different orifice diameters had on the flow were also analyzed. The results indicated that extremely high pressures can be generated from both waterhammer and air compression during the filling process. These pressures tend to increase as the orifice diameter is reduced. However, below a certain size the orifice constricts the air discharge enough to stop the water prior to its reaching the orifice. This results in an oscillatory behavior of the flow, and the relation between waterhammer and orifice diameter becomes much more difficult to predict. The results also demonstrated that these pressures are significantly reduced for longer pipe lengths, and for pipes with smaller diameters or otherwise offering greater frictional resistance to the flow. / M.S.

In the spring of 1998, a closed end gravity flow pipeline was installed in the Lethbridge Northern Irrigation District. The pipes ranged from 900 mm to 300 mm in diameter. / Manholes were placed at several locations along the pipeline and were used to install velocity meters and pressure transducers, which recorded data every second. Pressures and velocities during periods of steady state were used to calculate the head loss, Re and the Hazen-Williams friction factor, "C", along lengths of constant diameter. / The results were compared to the industry design standard of C = 150 (used for the design of rigid PVC pipe installations) and to the theoretical hydraulically smooth line developed from the Moody diagram and the Darcy-Weisbach equation. Since the maximum and minimum calculated values of C came in the 750 mm and 900 mm diameter pipes, respectively, and all other C values, including those from the 300 mm and 650 mm diameters, fell between these, pipe diameter was assumed not to be a variable. Therefore all the field data was averaged. The average value of Re for the range studied was 9.73 x 105 . The corresponding best-fit C value is 147.7, which is 6.0% lower than the derived theoretical maximum. Since the derived theoretical maximum is the ideal condition and the recorded data was slightly lower and therefore determined be a good representation of what can be expected in true field conditions.

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