The Effect of Wake Turbulence Intensity on Transition in a Compressor Cascade
Direct numerical simulations of separating flow along a section at midspan of a low-pressure V103 compressor cascade with periodically incoming wakes were performed. By varying the strength of the wake, its influence on both boundary layer separation and bypass transition were examined. Due to the presence of small-scale three-dimensional fluctuations in the wakes, the flow along the pressure surface undergoes bypass transition. Only in the weak-wake case, the boundary layer reaches a nearly-separated state between impinging wakes. In all simulations, the flow along the suction surface was found to separate. In the simulation with the strong wakes, separation is intermittently suppressed as the periodically passing wakes managed to trigger turbulent spots upstream of the location of separation. As these turbulent spots convect downstream, they locally suppress separation.
This is a manuscript of an article published as Wissink, Jan G., Tamer A. Zaki, Wolfgang Rodi, and Paul A. Durbin. "The effect of wake turbulence intensity on transition in a compressor cascade." Flow, Turbulence and Combustion 93, no. 4 (2014): 555-576. The final publication is available at Springer via DOI: 10.1007/s10494-014-9559-z. Posted with permission.