Pressure distribution and similarity theory of an elbow flowmeter based on experiments and CFD simulations

In this study, computational fluid dynamics was used to simulate the flow field of fluids through an elbow pipe. Subsequently, an elbow flowmeter was experimentally studied under the same conditions. The simulation results agreed well with the experimental data, with an error of < 10%. The turbulence model, difference scheme, and grid distribution used in the numerical calculation closely matched the actual flow state. Results showed that pressures inside and outside the elbow pipe exhibited the same trends at different flow rates. Pressures outside the elbow pipe gradually increased at the inlet of the elbow pipe, tended to be flat at ~ 30°, reached their maximum value at 60°, and began to decrease at 70°. The inner pressure dropped sharply at the sensor inlet, reached its minimum value near 30°, and then began to increase sharply. Overall distribution of the differential pressure showed a trend of first increasing and then decreasing, and the maximum differential pressure was ~ 30°. The feasibility of similarity theory was verified, laying a foundation for subsequent theoretical research involving elbow flowmeters.