Discharge Analysis of SMBF Flumes in Free and Submerged Flow Conditions

Document Type : Research Paper

Authors

1 PhD Candidate of Water Structures, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, P. O. Box 4111, Karaj, 31587-77871, Iran.

2 Associate Professor, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, P. O. Box 4111, Karaj, 31587-77871, Iran.

3 Full Professor, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, P. O. Box 4111, Karaj, 31587-77871, Iran.

Abstract

One of the most commonly used devices for flow measurements in open channels is the flume, in which the flow velocity increases due to the lateral contraction, raising the bottom of the channel, or a combination of both them. SMBF is a flume with the above mentioned properties, having two semi-cylinders on the side walls of the channel that contract the cross-sectional area of the flow. In this study, the SMBF flume has been studied for measuring the flow in free and submerged flow conditions. Using the experimental data (575 runs) of two rectangular channels, and using eight SMBF flumes, the proposed discharge equations were examined for the wide ranges of flow discharge, upstream depth, and contraction ratio. In the present study, based on the numerical and experimental analysis, and by measuring the velocity distribution at the throat section, non-uniformity of velocity distribution and depth in the contracted section, as well as the two-dimensional nature of flow were studied. Then, by considering the flow correction coefficients in the throat section and applying them into the energy equation, an equation was developed for estimating the flow discharge‎ under free flow conditions. Also, two equations were developed to determine the submergence threshold (as a function of upstream depth and throat width) and for the discharge estimation under submerged conditions. The mean absolute relative error of the estimated flow discharge of the SMBF flumes in free flow conditions and based on three experimental data series (channel 1, channel 2, and other researcher’s data) were respectively estimated to be 2.82, 3.19 and 1.52%. Additionally, the mean absolute relative error of the estimating flow discharge in the submerged conditions was 5.51%. The results showed a feasible application of SMBF structure, as a portable measuring instrument under free and submerged conditions.

Keywords

Main Subjects

References

Baiamonte, G., and Ferro, V. (2007). Simple flume for flow measurement in sloping open channel. Journal of irrigation and drainage engineering, 133(1), 71-78.
Carollo, F. G., Di Stefano, C., Ferro, V., and Pampalone, V. (2016). New Stage-Discharge Equation for the SMBF Flume. Journal of Irrigation and Drainage Engineering, 142(5), 04016005.
Di Stefano, C., Di Piazza, G. V., and Ferro, V. (2008). Field testing of a simple flume (SMBF) for flow measurement in open channels. Journal of irrigation and drainage engineering, 134(2), 235-240.
Lotfi Kolavani, F., Bijankhan, M., Di Stefano, C., Ferro, V., and Mazdeh, A. M. (2018). Flow measurement using circular portable flume. Flow Measurement and Instrumentation, 62, 76-83.
Lotfi Kolavani, F., Bijankhan, M., Di Stefano, C., Ferro, V., and Mazdeh, A. M. (2019). Experimental Study of Central Baffle Flume. Journal of Irrigation and Drainage Engineering, 145(3), 1-14.
Samani, Z. (2017). Three simple flumes for flow measurement in open channels. Journal of Irrigation and Drainage Engineering, 143(6), 04017010.
Samani, Z., and Magallanez, H. (1993). Measuring water in trapezoidal canals. Journal of irrigation and drainage engineering, 119(1), 181-186.
Samani, Z., and Magallanez, H. (2000). Simple flume for flow measurement in open channel. Journal of Irrigation and Drainage Engineering, 126(2), 127-129.
Samani, Z., Jorat, S., and Yousaf, M. (1991). Hydraulic characteristics of circular flume. Journal of Irrigation and Drainage Engineering, 117(4), 558-566.
Vatankhah, A. R. (2017). Discussion of “New Stage-Discharge Equation for the SMBF Flume” by Francesco Giuseppe Carollo, Costanza Di Stefano, Vito Ferro, and Vincenzo Pampalone. Journal of Irrigation and Drainage Engineering, 143(8), 07017011.
Iranian Journal of Soil and Water Research
Volume 50, Issue 7
December 2019
Pages 1635-1649

Files

Share

How to cite

Statistics