Experimental investigation of a turbulent natural convection flow in a cubic cavity with an inner obstacle partially heated

A. Weppe (1, 2, 3) , F. Moreau (1, 2, 3) , D. Saury (1, 2, 3)

1 COST - Convection, Optimisation, Systèmes Thermiques [Institut Pprime]
2 PPrime [Poitiers] - Institut Pprime [UPR 3346]
3 Département FTC - Département Fluides, Thermique et Combustion [Institut Pprime]

This work presents the dynamical and thermal behaviors of a turbulent natural convection flow occurring in a cubic cavity with an inner and partially heated obstacle. The top, bottom, front and back walls of the cavity are adiabatic and the other side walls are at imposed uniform temperature. Velocity and temperature measurements are carried out using Particle Image Velocimetry and micro-thermocouples. Boundary layer flows are observed in both vertical channels. A recirculating zone, in the upper part of the heated channel, breaks the linearity of the thermal stratification found in the lower part of the channel and it also disturbs heat transfers. A boundary layer instability of Tollmien-Schlichting type and the subsequent formation of an oscillating buoyant jet are analyzed. The presence of internal gravity waves in the thermally stratified heated channel are highlighted.

Mots clés: Prandtl number; transition; adjacent instability; mechanisms; conduction; transport; stabilitiy; velocity; block

Domaines: Thermique [physics.class-ph]; Thermique [physics.class-ph]

A. Weppe, F. Moreau, D. Saury. Experimental investigation of a turbulent natural convection flow in a cubic cavity with an inner obstacle partially heated. International Journal of Heat and Mass Transfer, 2022, 194, pp.123052. ⟨10.1016/j.ijheatmasstransfer.2022.123052⟩. ⟨hal-03680526⟩