Analysis of viscosity effect on turbine flowmeter performance based on experiments and CFD simulations

• Multi-viscosity experiments were carried out to analyze viscosity effect on turbine flowmeter performance.
• CFD simulation was carried out to analyze 3D internal flow fields of turbine flowmeter.
• The wake flow behind the upstream flow conditioner blade changes with viscosity.
• Viscosity changes affect the distribution of pressure on the rotor blades.
• The distribution of pressure on the rotor blades affects turbine flowmeter performance.

Viscosity effect is one important factor that affects the performance of turbine flowmeter. The fluid dynamics mechanism of the viscosity effect on turbine flowmeter performance is still not fully understood. In this study, the curves of meter factor and linearity error of the turbine flowmeter changing with fluid viscosity variations were obtained from multi-viscosity experiments (the viscosity range covered is 1.0×10–6 m2/s–112×10–6 m2/s). The results indicate that the average meter factor of turbine flowmeter decreases with viscosity increases, while the linearity error increases. Furthermore, Computational Fluid Dynamics (CFD) simulation was carried out to analyze three-dimensional internal flow fields of turbine flowmeter. It was demonstrated that viscosity changes lead to changes of the wake flow behind the upstream flow conditioner blade and the flow velocity profile before fluid entering turbine rotor blade, which affect the distribution of pressure on the rotor blades, so impact the turbine flowmeter performance.