×

zbMATH — the first resource for mathematics

Reactive control of transition induced by free-stream turbulence: an experimental demonstration. (English) Zbl 1118.76011
Summary: The present wind-tunnel experiment demonstrates that a reactive control system is able to decrease the amplitude of random disturbances in a flat-plate boundary layer. The disturbances were induced in a laminar boundary layer by a turbulent free stream. The control system consisted of upstream wall-shear-stress sensors (wall wires) and downstream actuators (suction through holes). An ad hoc threshold-and-delay control algorithm is evaluated and parameter variations were performed in order to find a suitable working point of the control system. Detailed measurements of the flow field show how the control influences the disturbances in the boundary layer, whereas the effect on the mean flow owing to the control is minute. The control system manages to inhibit the growth of the fluctuations of the streamwise velocity component for a considerable distance downstream of the two actuator positions. Further downstream, however, the amplitudes of the fluctuations grow again. The flow rate used to obtain the control effect is one sixth of that necessary if continuous distributed suction is used to reach the same control objective. Finally, correlations and spectra show that the elongation of the structures in the streamwise direction is eliminated in the regions where the control has the largest effect. The spanwise scale of the disturbances is not affected by the control.

MSC:
76-05 Experimental work for problems pertaining to fluid mechanics
76F70 Control of turbulent flows
76F06 Transition to turbulence
76F40 Turbulent boundary layers
PDF BibTeX XML Cite
Full Text: DOI
References:
[1] DOI: 10.1017/S0022112098001323 · Zbl 0927.76029 · doi:10.1017/S0022112098001323
[2] DOI: 10.1063/1.866989 · doi:10.1063/1.866989
[3] DOI: 10.1017/S0022112003006177 · Zbl 1094.76034 · doi:10.1017/S0022112003006177
[4] DOI: 10.1017/S0022112000002810 · Zbl 0963.76509 · doi:10.1017/S0022112000002810
[5] DOI: 10.1063/1.1683170 · Zbl 1186.76340 · doi:10.1063/1.1683170
[6] DOI: 10.1016/S0997-7546(03)00032-3 · Zbl 1049.76518 · doi:10.1016/S0997-7546(03)00032-3
[7] Inasawa, Exps. Fluids 34 pp 242– (2003)
[8] DOI: 10.1017/S0022112002001702 · Zbl 1161.76468 · doi:10.1017/S0022112002001702
[9] DOI: 10.1017/S0022112005005203 · Zbl 1073.76028 · doi:10.1017/S0022112005005203
[10] DOI: 10.1017/S0022112095000978 · Zbl 0867.76032 · doi:10.1017/S0022112095000978
[11] Gad-el-Hak, Appl. Mech. Rev. 42 pp 261– (1989)
[12] DOI: 10.1063/1.1509751 · Zbl 1185.76079 · doi:10.1063/1.1509751
[13] DOI: 10.1017/S0022112003003926 · Zbl 1049.76508 · doi:10.1017/S0022112003003926
[14] Bewley, J. Fluid Mech. 447 pp 179– (2001) · Zbl 1036.76027 · doi:10.1017/S0022112001005821
[15] Fasel, J. Fluid Mech. 450 pp 1– (2002)
[16] DOI: 10.1016/S0142-727X(00)00046-1 · doi:10.1016/S0142-727X(00)00046-1
[17] DOI: 10.1063/1.868605 · doi:10.1063/1.868605
[18] DOI: 10.1017/S0022112005003800 · Zbl 1070.76024 · doi:10.1017/S0022112005003800
[19] DOI: 10.1063/1.869962 · Zbl 1147.76382 · doi:10.1063/1.869962
[20] DOI: 10.1017/S0022112001007431 · doi:10.1017/S0022112001007431
[21] DOI: 10.1063/1.1775222 · Zbl 1187.76587 · doi:10.1063/1.1775222
[22] DOI: 10.1017/S0022112094000431 · Zbl 0800.76191 · doi:10.1017/S0022112094000431
[23] DOI: 10.1017/S0022112000002421 · Zbl 0983.76025 · doi:10.1017/S0022112000002421
[24] DOI: 10.1017/S0022112000002354 · Zbl 1010.76029 · doi:10.1017/S0022112000002354
[25] DOI: 10.1063/1.869908 · Zbl 1147.76308 · doi:10.1063/1.869908
[26] DOI: 10.1063/1.1313383 · Zbl 1184.76027 · doi:10.1063/1.1313383
[27] DOI: 10.1017/S0022112099007259 · Zbl 0959.76022 · doi:10.1017/S0022112099007259
[28] DOI: 10.1017/S0022112098003504 · Zbl 0951.76032 · doi:10.1017/S0022112098003504
[29] DOI: 10.1017/S0022112080000122 · Zbl 0428.76049 · doi:10.1017/S0022112080000122
[30] Klingmann, Eur. J. Mech. B/Fluids 12 pp 493– (1993)
[31] DOI: 10.1016/S0997-7546(00)01094-3 · Zbl 0960.76502 · doi:10.1016/S0997-7546(00)01094-3
[32] DOI: 10.1017/S0022112097008562 · Zbl 0922.76022 · doi:10.1017/S0022112097008562
[33] DOI: 10.1017/S0022112000002469 · Zbl 0983.76027 · doi:10.1017/S0022112000002469
[34] Waleffe, Stud. Appl. Maths 95 pp 319– (1995) · Zbl 0838.76026 · doi:10.1002/sapm1995953319
[35] DOI: 10.1063/1.1381563 · Zbl 1184.76447 · doi:10.1063/1.1381563
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.