6533b854fe1ef96bd12aec4a
RESEARCH PRODUCT
On natural convection in a single and two zone rectangular enclosure
Michele CiofaloG. BarbaroTassos G. Karayiannissubject
Fluid Flow and Transfer ProcessesNatural ConvectionNatural convectionMaterials scienceConvective heat transferEnclosureMechanical EngineeringThermal resistanceThermodynamicsLaminar flowRayleigh numberMechanicsHeat TransferCondensed Matter PhysicsNusselt numberPhysics::Fluid DynamicsLaminar FlowHeat transferBoussinesq approximation (water waves)CFDSettore ING-IND/19 - Impianti Nuclearidescription
Abstract Convective heat transfer was investigated numerically for rectangular enclosures both undivided and divided in two zones by a vertical partition, and having opposite isothermal walls at different temperatures. The aspect ratio was varied from 0.1 to 16 and the Rayleigh number from 3.5 ∗ 10 3 to ∗ 10 7 (non-partitioned enclosures) and from 1.0 ∗ 10 5 to 1.6 ∗ 10 8 (partitioned enclosures). The thickness and conductivity of the partition were varied. The end wall thermal boundary conditions were adiabatic or LTP (Linear Temperature Profile). The continuity, momentum and energy equations for a 2-D laminar steady flow were solved under the Boussinesq approximation by using a finite-difference method and the SIMPLEC pressure-velocity coupling algorithm. Grid-independent results indicate that the reduction in the Nusselt number caused by a thin central partition can be predicted within a few per cent (in the range investigated) by assuming the partition to be isothermal, i.e. infinitely conducting. The finite conductivity of the partition causes a temperature distribution along its length, resulting in an increase in Nu which depends on Rayleigh number, aspect ratio and end wall thermal boundary conditions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1992-07-01 | International Journal of Heat and Mass Transfer |