Publication Details
Abstract
Accurate measurement of water flow velocity and discharge is a fundamental task in hydrometry, irrigation engineering, and water resources management. Mechanical current meters of the propeller (rotational) type remain widely used in field measurements due to their robustness, simplicity, and suitability for open-channel and river flow conditions. However, the accuracy of such instruments strongly depends on proper calibration, flow conditions, and measurement methodology. This paper presents an experimental investigation and mathematical modeling of water flow velocity and discharge measurements using a propeller-type current meter. The operating principle of the instrument is analyzed, and a linear calibration model relating flow velocity to the rotational frequency of the propeller is formulated. Discharge is determined by integrating point velocity measurements over the cross-sectional area of the flow. Experimental measurements were conducted under controlled hydraulic conditions, and the obtained data were processed using statistical and analytical methods. The results demonstrate a stable linear relationship between the propeller rotational speed and flow velocity within the investigated range, confirming the applicability of the proposed calibration model. Discharge values calculated from measured velocity profiles show good agreement with reference measurements. The presented methodology provides a reliable and practical approach for flow monitoring in hydrometric applications and can be effectively applied in irrigation canals, rivers, and hydraulic engineering practice.