Swirling flow evolution Part 2: Streamflow 2D+t model validated with stereo PIV measurements

Inlet swirl distortion is currently an important aspect of research for highly embedded engines (BLI, etc). StreamFlow is a numerical tool developed at Virginia Tech to assist in the design of StreamVane™ swirl generators for experimental testing of fan response. This model calculates the downstream flow development of a StreamVane discharge swirl profile, enabling prediction of distortion intensity, extent, and location. This model solves these profiles on the order of seconds, thus making it a very useful, interactive design tool. The results of the model have been validated against stereoscopic PIV experimental data. The intensity and migration of the flow structures in the initial profile were well matched by the model. RMS averaged errors are on the order of 3 − 6% for in-plane flow velocities and 2−4° for radial and tangential flow angles. The inviscid, streamwise-vorticity driven model matches well with the experimental data; providing further evidence that the dominant physics have been properly identified. StreamFlow satisfies a need that has been identified previously,^1,2 and therefore is an enabling technology that facilitates significantly improved design of StreamVanes for higher fidelity replication of desired flow fields. These StreamVanes can then be used more effectively for improved assessment of the performance of downstream flow machines.