Development of a Test Rig for a New Vertical Ultra-Low-Head Hydro Turbine with Calibration of Rectangular Notch for Discharge Measurement

A new vertical ultra-low head hydro turbine has been conceptualized for power generation from water resources on shallow land regions with heads less than 3 m down to 0.5 m. This research reports the development of an experimental setup required for the testing of a newly conceptualized turbine along with the calibration of the rectangular notch used on it and is the novelty of this research. The methodology adopted for the development started with the identification of variables required on the test rig followed by design, fabrication, and testing for the calibration of the notch. The major design point for sizing the test rig was taken for a maximum flow rate of 120 LPS and a maximum upstream head over the turbine of 0.75 m. The overall dimension of the test rig designed was 9 m x 1.2 m x 1.5 m on four different sections assembled with nuts and bolts. The guidelines for installation of a rectangular notch, ISO 1980 was followed for sizing of notch. The trials for all the possible flow rates were found satisfactory as per the concept and tests were covered for calibration. The coefficient of discharge was found to increase from 0.575 to 0.617 for the increasing flow rate and height of the water column over the notch. The uncertainty band of ±0.67% on the measurement of flow for the turbine design condition was calculated. The advanced method and equipment are recommended for more precise results on flow measurement.