The 2021 MRV Challenge: Introduction and Stanford-USMA Results

This presentation is part of the 2021 Magnetic Resonance Velocimetry (MRV) Challenge which was created to test the accuracy of phase averaged, three-dimensional, three component (4D3C) MRV measurements in periodic flows across multiple MR system platforms and flow labs around the world. The results from the combined team of researchers from Stanford University and the United States Military Academy (USMA) are presented. Experiments were performed on a square cross-section water channel containing a periodic array of rectangular buildings and an injection site in the floor behind one building at a channel Reynolds number of 15,000. The injector was pulsed periodically to produce a transient, highly three-dimensional (3D) flow. 4D3C velocity measurements were obtained using a 3T GE whole body scanner and reconstructed to 20 phases across the injection cycle. Additional scan conditions are outlined, as well as an overview of the experimental techniques and equipment used. Detailed results are presented for the flow behavior during several phases of the injection cycle at multiple locations, particularly focusing on complex fluid dynamic behaviors that are highly three-dimensional in nature. Agreement with the results from the other international participants suggest an increased capacity to leverage MRI measurements for flows that are periodic in nature or that may be approximated using repeatable transients.