Experimental investigation into localized instabilities of mixed Rayleigh-Bénard-Poiseuille convection

• Lausanne: EPFL, 2008

An experimental study of the stability of the Rayleigh-Bénard-Poiseuille flow was performed in a large transverse aspect ratio channel. The onset for the transverse thermo-convective rolls was determined as a function of the Reynolds number for two different fluids (water: Pr = 6.5 and mineral oil: Pr = 450). Then, the system impulse response was studied and a good agreement with theory was found for the convective/absolute instability transition. Finally the response of the system to localized heating was observed and compared with analytical and numerical results by Martinand, Carrière and Monkewitz (2004 & 2006): experimental thermo-convective global modes are found to correspond to the saturated "steep" variety constructed by Pier, Huerre and Chomaz (2001).

Keywords: Rayleigh–Bénard–Poiseuille ; thermal convection ; absolute/convective instability ; global mode ; Schlieren ; Rayleigh–Bénard–Poiseuille ; convection thermique ; instabilité convective/absolue ; mode global ; Schlieren

Thèse École polytechnique fédérale de Lausanne EPFL, n° 4144 (2008)
Programme doctoral Mécanique
Faculté des sciences et techniques de l'ingénieur
Institut de génie mécanique
Laboratoire de mécanique des fluides

Reference

• doi:10.5075/epfl-thesis-4144
• Print copy in library catalog

Record created on 2008-05-22, modified on 2016-08-08