Numerical analysis and experimental comparison of temperature-compensation method for large length–diameter ratio thermal mass flowmeter

Abstract

Thermal mass flowmeters (TMFs) are inherently sensitive to temperature fluctuations, which can result in inaccurate measurements. This study focuses on a novel TMF named the large length–diameter ratio thermal mass flowmeter (LLRTMF), which was previously proposed for its insensitivity to the distribution of radial flow velocity and implemented via a variable-speed, variable-temperature experimental setup. The power characteristics of the LLRTMF are investigated over velocity and temperature ranges of 1.00–6.00 m/s and 283.0–319.0 K, respectively. The experimental results indicate that the maximum relative error of the experimental power consumption is 21.96 %. Additionally, a full-size numerical model of the LLRTMF is developed to simulate its power characteristics across wider velocity and temperature ranges of 0.25–16.00 m/s and 283.0–353.0 K, respectively. Experimental data are used to verify the accuracy of the simulation model. Using the numerical model, an empirical correlation equation between power and velocity is derived and polynomially fitted to establish a temperature-compensation equation. The results of the temperature compensation equations and experiment were compared. The maximum relative error of the absolute value was 20.84 %, i.e., less than the maximum error in the results of the experiment due to temperature change, confirming the validity of the formula.