Author(s): Aniruddha D. Ghare, Avinash D. Vasudeo, Avinash M. Badar
Linked Author(s): Aniruddha Ghare
Keywords: Conical flume, canals, agriculture, discharge prediction, critical flow
Abstract: For better water management for agriculture, canal water flow measurement at desired location at desired time is essential. The flow measurement in canal can be carried out by using different flumes or electromagnetic devices, which are generally expensive. Most of the arrangements are of non portable type and require that those be permanently installed in canals for measurement of flow-rates. India is an agricultural country where large number of networks of canals are found, whose cross-sections are mostly trapezoidal. The scarcity of water over the globe necessitates the need for measurement of even small flows through the field canals for better conservation and management of water. The portable flumes with their discharge prediction models shall be of great help in small canal flow measurements leading to achievement of goal of water conservation. Literature shows a few demonstrated studies on the use of regular shaped obstructions viz. cylinders, prisms and cones for creation of constriction to the canal flow and the resulting stage-discharge relationships. However, literature shows limited number of experimental studies on conical obstructions in a trapezoidal channel. This study elaborates a flume where constriction is obtained by inserting a cone at the center of a trapezoidal canal. This arrangement is referred as a simple conical flume. An experimental investigation of two different portable conical flumes placed in a trapezoidal canal with side slopes of 1 H: 1V to produce critical flow conditions, has been carried out. The observations from the laboratory experiments on the flume have been analyzed and two different discharge prediction models have been developed for determination of discharge. The results from the developed mathematical models have been compared with the measured flow rates obtained from the additional experimental data that is collected for its validation. Thus, the presented calibrated flume can be an interesting alternative as compared to other stationary flumes for flow rate predictions, particularly in case of small trapezoidal open canals. However, more exhaustive experiments shall have to be conducted to propose a general discharge prediction model that would account for different constriction ratios as well as canal side slopes
Year: 2017