Entry transition water surface profile prediction in supercritical partially filled pipe flow

The criteria governing the development of steady partially filled supercritical pipe flow are presented together with the necessary techniques to determine the water surface profile in the pipe entry transition length. The establishment of full bore flow is predicted for a range of flow rates and pipe design parameters. Based on the water surface profile calculation technique, the report presents pipe length predictions to avoid the air pressure fluctuations in the drainage system that result from full bore flow establishment. Findings allow design decisions to be made that link pipe slope, diameter, and roughness to the need to avoid full bore flow. A graphical technique is also presented that removes the necessity to interpolate from the tabular data. The effect of entry geometry loss coefficients is included.