Séminaire CPU_Tapan K. Sengupta " Recent Developments in Fluid Flow Transition for External Flows"le 11 février 2016 de 14h à 15h
Dans le cadre de son axe "Calcul scientifique" (Axe 1), le cluster CPU accueillera Tapan K. Sengupta (IIT Kanpur, INDIA) qui présentera ses travaux lors d'un exposé intitulé "Recent Developments in Fluid Flow Transition for External Flows".
Le séminaire aura lieu le 11 Février 2016, à 2h à l'ENSCBP (Bat A. Amphi. 2/ 16 Av Pey-Berland/33607 Pessac).
Tapan K. Sengupta (High Performance Computing Laboratory, Dept. of Aerospace Engineering, IIT Kanpur, INDIA)
Titre: Recent Developments in Fluid Flow Transition for External Flows
Résumé: To understand transition to turbulence via two- and three-dimensional routes of disturbance growth, results obtained from the solution of Navier-Stokes equation (NSE) by high accuracy compact schemes will be reported which reproduce classical experiments of Schubauer-Skramstad (1947). The experiments used low disturbance tunnel at NBS and imposed deterministic harmonic excitation inside the shear layer. This scenario was studied in Sengupta and Bhaumik [Phys. Rev. Lett. 107, 154501 (2011)], where a route of transition to fully developed turbulent stage was explained for 2D disturbances in terms of the spatio-temporal wave-front (STWF). The STWF was identified as the unit process of 2D turbulence creation. Theoretical prediction of STWF for boundary layer was reported earlier in Sengupta et al. [Phys. Rev. Lett. 96, 224504 (2006)] from the Orr-Sommerfeld equation as due to spatiotemporal instability.
Recently we have shown the same unit process of the STWF for transition involving 3D disturbance field from DNS. These findings have renewed interest in this field that shows the importance of STWF over Tollmien-Schlichting waves, which was considered central for flow transition by low amplitude disturbances.