THE EFFECT OF CAVITATION ON A CONE FLOWMETER: A NUMERICAL INVESTIGATION

The cone flowmeter is widely used in many industry processes for its advantages including high accuracy, low pressure loss, wide range ability, and short installation requirements. When the pressure in the flowmeter drops below the liquid vapor pressure, the cavitation will occur in flowmeter, and thus may affect its measurement accuracy. However, the effect of cavitation on measurement performance of a cone flowmeter remains unclear and few published studies are available on this issue. In the present work, the measurement performance of a cone flowmeter was numerically investigated when measuring the liquid, such as the water, the liquid oxygen, the liquid nitrogen, and the liquid hydrogen. The Schnerr-Sauer cavitation model and the Realizable K-epsilon turbulence model were employed. A user-defined function (UDF) was implanted into Ansys Fluent to consider the effects of latent heat of vaporization. Emphases were put on the effect of cavitation on the discharge coefficient and thus on the measurement accuracy of the cone flowmeter. The results show that there is little effect of cavitation on the discharge coefficient before the cavitation significantly affects the pressure distribution around the low-pressure port. In the "stable region," the cone flowmeter can accurately predict the liquid flow rate with the relative error range of +/- 0.5%. The results also demonstrate that the effect of cavitation on the measurement accuracy of the flow rate is small.