Design and Development of a Low-Cost Cantilever-Based Flow Sensor

Abstract

Measuring fluid flow rate in a precise manner plays a vital role in process engineering with important objectives, including monitoring and controlling of process operations to improve productivity and ensure safety. Flow sensing is a well-studied problem to the extent, even there exist many sophisticated sensors. Despite the vast developments, there are matters of concern, particularly in residential and irrigation sectors. The existing sensors are expensive, unidirectional, and less efficient in measuring low flow rates. Hence, the development of low-cost, robust and accurate flow sensors with the simplicity in operation is highly demanded. This work presents a novel low-cost flow sensor based on the principle of cantilever deflection. The proposed flow sensor uses a stainless steel strip as the sensing element and measures the flow based on the angle of deflection of the cantilever through an image analysis technique. A calibration model that relates the flow rate to the angle of deflection is developed from experimental data. The results are subsequently non-dimensionalized in terms of Reynolds number, thereby extending its applicability to other fluids and accommodate pipes of different dimensions. In addition, a simplified theoretical model based on the cantilever deflection mechanism is presented in support of the working principle. The developed cantilever flow sensor is cost-effective, simple, reliable, and capable of measuring even moderate flow rates in the pipeline. Experimental results are presented to demonstrate the precision and accuracy of the proposed flow sensor.