Fourier Collocation Approach With Mesh Refinement Method for Simulating Transit-Time Ultrasonic Flowmeters Under...

Area of Science:

• Fluid dynamics
• Acoustics
• Numerical modeling

Background:

• Transit-time ultrasonic flowmeters are crucial for fluid measurement.
• Accurate flow measurement in multiphase conditions presents significant challenges.
• Existing numerical models require refinement for multiphase flow applications.

Purpose of the Study:

• To enhance a previously developed numerical model for transit-time ultrasonic flowmeters operating under multiphase flow conditions.
• To investigate the impact of mesh refinement and grid point redistribution on model accuracy.
• To evaluate the performance of both clamp-on and in-line ultrasonic flowmeters in multiphase flows.

Main Methods:

• The numerical model was extended using mesh refinement and grid point redistribution.
• Modified first-order stress-velocity equations of elastodynamics were solved, incorporating background flow effects.
• Spatial derivatives were computed using a Fourier collocation scheme with the fast Fourier transform.
• Time integration was performed using an explicit third-order Runge-Kutta finite-difference scheme.

Main Results:

• The enhanced model demonstrates improved accuracy in simulating multiphase flow conditions.
• Comparisons against analytical solutions and experimental data validate the benefits of mapped grids.
• The study provides insights into the performance characteristics of clamp-on and in-line ultrasonic flowmeters.

Conclusions:

• Mesh refinement and grid redistribution significantly enhance the predictive capability of ultrasonic flowmeter models for multiphase flows.
• The validated numerical model offers a reliable tool for analyzing and optimizing ultrasonic flow measurement systems.
• Further research can explore advanced numerical techniques for even greater precision in complex flow regimes.