摘要

Experimental measurements made using Magnetic Resonance Velocimetry (MRV), a technique based on Magnetic Resonance Imaging (MRI) principles, are presented for the 3D velocity field in the turbulent flow downstream of a backward facing step in a square channel with a Reynolds number of 48,000 based on the step height and the freestream velocity at the step edge. Results include the three-component mean velocity field measured using phase-contrast MRI methods and turbulent Reynolds stresses measured using a method based on diffusion imaging principles. MRV results are compared to particle image velocimetry (PIV) measurements made in the centerplane of the flow at several locations downstream of the step. The MRV and PIV mean velocity measurements show excellent agreement in all regions of the flow. The MRV measurements for the Reynolds normal stresses are in agreement with the PIV to within +/-20%.