Experimental Investigation of Two-Stream Mixing Flow with Multiple Tabs

Vortex-generating tabs arranged in the form of an array have been examined experimentally using a laser Doppler anemometer in a two-stream mixing e ow situation. The vortex-generating tabs are the “ delta tabs,” i.e., triangular-shaped protrusions into thee ow attached to the trailing edge of the splitterplate. A velocity ratio of 2:1 (upper and lower ) between the two coe owing streams was used. Three arrangements for the tabs are investigated. Case 1 has all of the tabs located on the high-speed side. The tabs are located alternatively on either side of the splitterplateforcase2,ande nally,case3issimilarto case2,butthetabon thelow-speedsideistilted upstream (i.e., similarto a delta-wing vortex generator ). Mutualcancellation between streamwise vorticesrotating in theopposite sense was observed in case 1, whereas in case 2 the merging of streamwise vortices rotating in the same sense had delayed the decay of the streamwise vorticity. For case 3 the upstream tilted tab appeared to have generated relatively weak streamwise vortices so that they were canceled off by the vortices generated on the high-speed side near the trailing edge. Finally, the turbulence characteristics for each case are presented and discussed.