Effect of clearance on measuring accuracy in two-dimensional piston flowmeter

Accurate measurement of flow rates is essential in both industrial and scientific domains, with positive displacement flowmeters being particularly valued for their precision across diverse hydraulic engineering applications. This article offers an overview of piston flowmeters and delineates a cutting-edge two-dimensional (2D) piston flowmeter, expounding on its architectural and operational principles. Existing mathematical models have proven insufficiently effective in analyzing experimental results. In response to this deficiency, and to further scrutinize the flowmeter's empirical performance, the paper introduces an advanced mathematical model that explicitly considers the clearance between the rollers and the cam tracks inside the metering unit. The analytical solutions of the new model reveal a positive correlation between the increase in clearance size and the rise in discharge coefficient of the flowmeter, manifesting as alterations in the 2D piston motion pattern. Comparative to steady flow rate calibration results from prior studies, the newly calculated compensated discharge coefficient proves to more accurately predict the flowmeter's performance within the measurement range.