BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:Receptivity and Instability : Role of Spatio-Temporal Wave Front I
 n Transition 
DTSTART:20160223T111500
DTEND:20160223T121500
DTSTAMP:20260501T195602Z
UID:70380984aa488d1b7fefae96805aa56e4c74aca98bf720a369851fa7
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Tapan K. Sengupta\nTo understand the unit process(es) of
  transition to turbulence via two- and three-dimensional routes of low amp
 litude disturbance growth over a zero pressure gradient boundary layer (ZP
 G-BL) remains the canonical problem. There are numerous attempts to unders
 tand the process for ZPG-BL. In the present talk\, results obtained from s
 olutions of Navier-Stokes equation and its linearized parallel flow versio
 n will be presented which reproduce classical experiment of Schubauer-Skra
 mstad (1947). The experiments used low disturbance tunnel at NBS and impos
 ed 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 exp
 lained for 2D disturbances in terms of the spatio-temporal wave-front (STW
 F). The STWF was earlier identified as the unit process by theoretical rec
 eptivity solution of Orr-Sommerfeld equation by Bromwich contour integral 
 method in Sengupta et al. [Phys. Rev. Lett. 96\, 224504 (2006)] as due to 
 spatiotemporal instability. Of late\, we have reported the same process of
  the STWF for transition involving 3D disturbance field from DNS. These fi
 ndings show the importance of STWF over Tollmien-Schlichting waves\, which
  was considered central for flow transition by low amplitude disturbances.
LOCATION:Room MAA110 http://plan.epfl.ch/?room=MA%20A1%2010
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR