Author(s): S. M. Borghei; A. H. Zabolipour; A. Bohluli
Linked Author(s):
Keywords: Two phase flow; Slug flow; Rectangular tunnel; Experimental tests; Pressure variation
Abstract: Two phase slug flow often happens in culvert and water tunnels conveying water from dams and weirs. Having complicated hydraulic properties, little is known about different hydraulic properties of this kind of flow, while most of the previous studies deal with other liquids than water and air, mostly dealing with chemical and mechanical engineering problems. In this paper, the results from experimental study of air/water slug flow due to change in slope of the conduit from horizontal to 2,3 and 4% are presented. The conduit has rectangular cross section with dimension of 6x10 cm of Plexiglas material and includes 320 cm of length in the horizontal section and 180 cm length in the inclined part. Air is added to the system upstream of the conduit using an air compressor. The variables, beside the conduit slope, include; water and air discharge. The experimental set-up includes; digital camera, piezometers and pressure transducers. The results are expressed as graphs and design guides showing the hydraulic changes in the slug (e.g., slug period, slug length and pressure) due to slope change in the conduit. The pressure fluctuations recorded at the slope change section shows that reinforcements would be needed for the tunnel.
Year: 2009