Full Field Velocity and Temperature Measurements Using Magnetic Resonance Imaging in Turbulent Complex Internal Flows
Flow and heat transfer in complex internal passages are difficult to predict due to the presence of strong secondary flows and multiple regions of separation. Two methods based on magnetic resonance imaging called 4D magnetic resonance velocimetry (4D-MRV) and thermometry (4D-MRT) are described for measuring the full-field mean velocities and temperatures, respectively, in complex internal passage flows. 4D-MRV measurements are presented for flow through a model of a gas turbine blade internal cooling passage geometry with Reh = 10,000 and compared to PIV measurements in a highly complex 180° bend. Measured three-component velocities provide excellent qualitative and quantitative insight into flow structures throughout the entire flow domain. The velocities agree within ±10% in magnitude and ±10° in direction in a large portion of the bend which is characterized by turbulent fluctuations as high as 10–20% of the passage inlet bulk velocity. Integrated average flow rates are accurate to 4% throughout the flow domain. Preliminary 4D-MRV/MRT results are presented for heated fully developed turbulent pipe flow at ReD = 13,000.