Name: ALEXANDRE DE OLIVEIRA E OLIVEIRA
Publication date: 25/02/2026
Summary: Flow rate measurement is critical in industrial processes, particularly in the oil and gas sector, where high uncertainties in fiscal measurements can lead to significant economic losses. Among the most widely used devices, the orifice plate stands out. Although it performs efficiently under single-phase flow conditions, the presence of liquid in the gas stream (up toXLM = 0.3), characterizing wet gas flow, compromises measurement accuracy and introduces a positive error known as overreading. To mitigate this effect, a modified orifice plate configuration is proposed, consisting of attaching an electrical heating element
to the plate wall and incorporating surface temperature measurements. This approach enables the evaluation of heat transfer mechanisms governed by conduction and forced convection in gas–liquid two-phase flows. The analysis focuses on the relationship between the convective heat transfer coefficient and the Nusselt number, considering its dependence on dimensionless parameters such as the Froude number and the Lockhart–Martinelli parameter. Computational Fluid Dynamics (CFD) results demonstrate that flow restriction caused by the orifice plate leads to the formation of a vena contracta region, intensifies the core flow velocity, and generates recirculation zones that directly affect heat transfer at the plate surface. Variations in flow velocity enhance thermal gradients and reduce the average internal temperature of the device, while the liquid phase introduces thermal asymmetries between the upper and lower portions of the plate, particularly at low velocities. A generalized correlation for the Nusselt number as a function of the Froude number and the Lockhart–Martinelli parameter was proposed using a hierarchical nonlinear parametric modeling approach. The model exhibited excellent agreement with numerical
data, presenting low error levels and high coefficients of determination, with R2 > 0.99, demonstrating strong potential for application in alternative wet gas flow measurement methods.
Keywords: Flow measurement; Wet gas; Orifice plate; Overreading; Heat transfer; Nusselt number; CFD.
