Numerical Study of Laminar-turbulent Transition on a Platein a Low-Speed Tunnel with Contoured Wall

Laminar-turbulent transition flow phenomena on a flat plate in a low-speed wind tunnel at different Reynolds numberswere studied numerically. The now calculation is based on an inviscid/boundary layer interaction method with modifiedAbu-Ghannam/Shaw (AGS ) transihon criterion. The test sechon has non- symmetric al contoured walls, and the plate islocated biased the bottom side with a height ratio of 26: 14. In test case of steady flow, a laminar-turbulent transihontakes place and a small separation bubble occurs on the upper side of the plate, when the inlet Reynolds number is assmall as 0.63lx10-6. The predicted transihon location agrees well with that of the test results, but the separation bubbleis hardly to see from the calculatod velocity profiles though the printed data of velocity in this region do show thenegahve values. The further numerical Predictions with different Reynolds numbers corresponding to the incoming flowvelocities show that when the Reynolds number is greater than 1.379xl0-6, the separahon bubble does not occur, whichis coincident with the experimental results. The influence of the side wall geomeny on the transihon on the plate is alsostudied.