Mixed Convection in a Ventilated Enclosure with Different Heater Position
Abstract
A comprehensive investigation on mixed convection in a ventilated enclosure has been carried out numerically for different positions of heat sources at the sidewalls. The relative position of the isothermal heat source and heat sink on both vertical walls influences the heat transfer process. Different configurations are simulated using an in-house developed CFD code, based on finite volume method. The characteristics of heat transfer, flow complexity and entropy generation are calculated as a function of Richardson number (Ri = 0.01–100) and Reynolds number (Re = 100). The results for different position of heat sources and heat sinks are presented along with isotherms, streamlines and Bejan number. The results show that the performance with middle-middle position of heat source is always superior.
Keywords
Mixed convection Ventilated enclosure Heater position Heat transfer enhancement Entropy generationNomenclature
- Be
Bejan number \( ( = NS_{cond} /NS) \)
- g
Acceleration due to gravity
- Gr
Grashof number
- k
Thermal conductivity
- L
Length scale
- NS
Dimensionless entropy generation
- Nu
Local Nusselt number
- P
Dimensionless pressure
- Pa
Ambient pressure
- Pr
Prandtl number
- \( q_{in} \)
Heat input through hot walls
- Re
Reynolds number
- Ri
Richardson number
- T
Temperature
- T*
Dimensionless reference temperature \( (=T_{c} /(T_{h} - T_{c} )) \)
- u, v
Velocity in x and y directions
- U, V
Dimensionless velocities
- x, y
Cartesian coordinates
- X, Y
Dimensionless coordinates
- \( \alpha \)
Thermal diffusivity
- \( \beta \)
Thermal expansion coefficient
- \( \theta \)
Dimensionless temperature
- \( \mu \)
Dynamic viscosity
- \( \upsilon \)
Kinematic viscosity
- \( \rho \)
Fluid density
- \( \tau \)
Dimensionless time
- \( \psi \)
Dimensionless streamfunction
- \( \Upphi \)
Irreversibility distribution ratio
Subscripts
- avg
Average
- cond
Conduction
- visc
Viscous dissipation
- c, h
Cold wall, Hot wall
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