Discharge coefficient of a semi-elliptical side weir in subcritical flow

Abstract A labyrinth weir is an overflow weir, folded in plan view to provide a longer total effective length for a given overall weir width. The total length of the labyrinth weir is typically three to five times the weir width. In this study, a semi-elliptical labyrinth weir was used as a side weir structure. Rectangular side weirs have attracted considerable research interest. The same, however, is not true for labyrinth side weirs. The present study investigated the hydraulic effects of semi-elliptical side weirs in order to increase their discharge capacity. To estimate the outflow over a semi-elliptical side weir, the discharge coefficient in the side weir equation needs to be determined. A comprehensive laboratory study including 677 tests was conducted to determine the discharge coefficient of the semi-elliptical side weir. The results were analyzed to find the influence of the dimensionless weir length L / B , the dimensionless effective length L / l , the dimensionless weir height p / h 1 , the dimensionless ellipse radius b / a , and upstream Froude number F 1 on the discharge coefficient. It was found that the discharge coefficient of semi-elliptical side weirs is higher than that of classical side weirs. Additionally, a reliable equation for calculating the discharge coefficient of semi-elliptical side weirs is presented.

[1]  Olivier Blanpain,et al.  Free surface measurement of flow over side weirs using the video monitoring concept , 2004 .

[2]  W Frazer.  THE BEHAVIOUR OF SIDE WEIRS IN PRISMATIC RECTANGULAR CHANNELS. HYDRAULICS PAPER NO 14. SYMPOSIUM OF FOUR PAPERS ON SIDE SPILLWAYS. , 1957 .

[3]  Mauro Fiorentino,et al.  Hydraulic features of supercritical flow along prismatic side weirs , 2001 .

[4]  Alireza Keshavarzi,et al.  A study of spatial variation of discharge coefficient in broad‐crested inclined side weirs , 2009 .

[5]  Masoud Ghodsian.  Supercritical flow over a rectangular side weir , 2003 .

[6]  Nihat Kaya,et al.  Discharge Capacity of Labyrinth Side Weir Located on a Straight Channel , 2010 .

[7]  Ali Uyumaz,et al.  Flow Over Side Weirs in Circular Channels , 1985 .

[8]  Willi H. Hager.  Supercritical Flow in Circular‐Shaped Side Weir , 1994 .

[9]  Smith,et al.  A THEORETICAL CONSIDERATION OF SIDE WEIRS AS STORMWATER OVERFLOWS. HYDRAULICS PAPER NO 11. SYMPOSIUM OF FOUR PAPERS ON SIDE SPILLWAYS. , 1957 .

[10]  W. Hager.  Lateral Outflow Over Side Weirs , 1987 .

[11]  A El Khashab,et al.  Experimental Investigation of Flow Over Side Weirs , 1976 .

[12]  Prabhata K. Swamee,et al.  Side-weir analysis using elementary discharge coefficient , 1994 .

[13]  H. Aǵaçcioǵlu,et al.  Discharge Coefficient of a Triangular Side-Weir Located on a Curved Channel , 2004 .

[14]  T. Nadesamoorthy,et al.  Discussion of Spatially Varied Flow over Side-Weirs by Kanakatti Subramanya and Subhash Chandra Awasthy , 1972 .

[15]  Nachimuthu Karunanithi,et al.  Neural Networks for River Flow Prediction , 1994 .

[16]  Hin-Fatt Cheong.  Discharge Coefficient of Lateral Diversion from Trapezoidal Channel , 1991 .

[17]  Yalçın Yüksel,et al.  SIDE-WEIR FLOW IN CURVED CHANNELS , 1998 .

[18]  Kanakatti Subramanya,et al.  Spatially Varied Flow over Side-Weirs , 1972 .

[19]  Kittur G. Ranga Raju,et al.  Side Weir in Rectangular Channel , 1979 .

[20]  Masoud Ghodsian,et al.  DISCHARGE COEFFICIENT FOR SHARP-CRESTED SIDE WEIR IN SUBCRITICAL FLOW , 1999 .

[21]  Santosh K. Pathak,et al.  TRIANGULAR SIDE WEIRS , 1987 .

[22]  D. Manivannan,et al.  Discharge Coefficient of Rectangular Side Weirs , 1994 .

[23]  Otto J. Helweg.  Microcomputer Applications in Water Resources , 1990 .

[24]  Ebubekir Yüksel.  Effect of specific energy variation on lateral overflows , 2004 .

[25]  Praxitelis A. Argyropoulos,et al.  Discussion of Spatially Varied Flow over Side-Weirs by Kanakatti Subramanya and Subhash Chandra Awasthy , 1972 .

[26]  William Frazer.  THE BEHAVIOR OF SIDE WEIRS IN PRISMATIC RECTANGULAR CHANNELS , 1957 .