INTERNATIONAL RESEARCH JOURNAL OF ENGINEERING AND TECHNOLOGY (IRJET) E-ISSN: 2395-0056 VOLUME: 07, SPECIAL ISSUE | JUNE 2020 WWW.IRJET.NET P-ISSN: 2395-0072 International Conference on Recent Trends in Science & Technology-2020 (ICRTST - 2020) Organised by: ATME College of Engineering, Mysuru, INDIA © 2020, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 77 Flow Measurements in Open Channel- A Literature Review Adarsh S 1 Research Scholar, Vidya Vikas Institute of Engineering and Technology, Mysuru Karnataka, India Dr M N Shesha Prakash 2 Vidya Vikas Institute of Engineering and Technology, Mysuru, Karnataka, India -------------------------------------------------------------------------------***-------------------------------------------------------------------------- Abstract: Flow measurement is an exciting and interesting topic in fluid mechanics which is extremely important and of late is gaining much importance due to mismanagement and its over-usage. In particular, water is an important and irrecoverable and irreplaceable resource, practically and absolutely required for sustainability of all living beings. Even the ground water has been overused resulting in its scarcity and the available quantity of water needs to be managed resourcefully which implies that the fluid needs to be measured. Assuming water to be nearly an ideal fluid, most of the researchers have used various methods to measure water in closed conduits and open channels. Most of it to be accurate is intrusive like weirs; notches etc. and few are non-intrusive devices like measuring flumes like Partial-flumes, Venturi- flumes, standing-wave flumes etc. The energy loss in these flow measuring devices is also relatively less. This paper is based on review of essential literature based on flow measurements in open channel and documenting the significance of the proposed research so that it could be a repository in the present field for researchers. Key words: Flow Measurement, Open channel flow, Flumes, Weirs. Introduction Open channel flow with free surface consist an interface between the moving fluid and asuperimposing fluid medium (usually air) with uniform pressure (usually atmospheric pressure). Further, channels are the devices which are used to convey water from source to destination. In Irrigation Engineering, Channels are like nervous system which carries water from stored place like reservoirs or tanks to the individual agricultural fields. The ultimate goal of flow measurement is to preserve water through improving distribution techniques and optimal usage. Focusing towards measurement, management and maintenance will be advantageous to the farmers which will in-turn help prevent low yields and other crop damage caused by under or over usage of water. At present, irrigation consumes about 84% of total available water making the maximum, followed by Industrial and domestic sectors consuming about 12% and 4% respectively. Flow measuring devices are commonly used to measure velocity and pressure or head. The head or velocity is measured first and then discharge is calculated through charts, tables, or equations. Generally, Water measuring devices use concept of pressure head h or pressure intensity p to determine discharge Q in flumes, weirs, orifices, and Venturi-meter. The point gauge or "weir sticks" are used to measure Q.Pressure or head is used with pipe flow meters such as venturi-meter. Devices including float and stopwatch, current-meter of propeller or cup & cone type and vane deflection meters are used to measure velocities, v. (M.Y. El-Ansary.et.al. 2010). In open channels DischargeMeasurement ofwaterplays a major role from viewpoint of conserving water. Anexclusive relationship between discharge and upstream head can be measured throughproper discharge measurement which is mandatory to manage water resources efficiently. Weirs, flumes and gates can be used to measure discharge in open channels for a long time (Arun Goel 2006). The basic concept of flow measurement is by inducing difference of pressure between two sections in closed conduits and difference in cross sectional area of flow (There by varying velocity in open channels Q = AV).