BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Turbulent heat transfer in wall-bounded flows - Genta Kawahara (Os
 aka University)
DTSTART:20220106T130000Z
DTEND:20220106T140000Z
UID:TALK166429@talks.cam.ac.uk
DESCRIPTION:If there is a difference in temperature between the bulk fluid
  and the wall surface in wall-bounded turbulent flows\, such as thermal co
 nvection and shear flow\, heat will be transferred between the fluid and t
 he wall. This is (convection) heat transfer\, which is dominated by therma
 l conduction but highly depends on flow characteristics. Turbulent heat tr
 ansfer is a significant problem not only in fluid mechanics but also in a 
 wide variety of engineering applications.In the first part of this talk\, 
 turbulent heat transfer in Rayleigh-B&eacute\;nard convection will be revi
 ewed\, with emphasis on widely observed scaling properties\, i.e. the clas
 sical scaling\, as well as the so-called ultimate scaling (corresponding t
 o the Taylor dissipation law\, i.e. inertial energy dissipation) suggested
  for extremely high Rayleigh numbers\, implying that a wall heat flux is i
 ndependent of thermal conductivity. Similarity and dissimilarity between h
 eat and momentum transfer will also be reviewed for wall-bounded turbulent
  shear flows\, in which the Taylor&rsquo\;s inertial dissipation does not 
 necessarily correspond to the ultimate heat transfer.In the second part\, 
 the feasibility of the ultimate heat transfer will be explored in turbulen
 t Rayleigh-B&eacute\;nard convection and turbulent channel flow. Wall perm
 eability\, which can be implemented on a porous wall\, is introduced in th
 ermal convection and shear flow. It is found that in both thermal convecti
 on and shear flow between the permeable walls\, the ultimate heat transfer
  can be achieved at high Rayleigh numbers and high Reynolds numbers\, resp
 ectively. It will be demonstrated why the wall permeability can lead to th
 e ultimate scaling in wall-bounded convective turbulence and sheared turbu
 lence.
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR