Combined Heat Transfer by Natural Convection – Conduction and Surface Radiation in an Open Cavity Under Constant Heat Flux Heating

Abstract

Combined heat transfer by natural convection-conduction and surface radiation in an open cavity heated by constant flux is studied here. The laminar flow is solved numerically by employing the SIMPLE algorithm with QUICK scheme. The numerical results show that both radiation and solid conduction increase the average total Nusselt number. The average total Nusselt number is a linear increasing function of emissivity when emissivity is larger than 0.2. The heat conduction of a conductive wall increases the total cooling effect, but its effect is close to a limit when the conductivity ratio exceeds 100. The increase due to radiation ranged from 54.1% to 64.0%.

Acknowledgments

The financial support from the Chinese National Natural Science Foundation under grants 50876067 and 50828601, and the Natural Science Fund of Shanghai No. 09ZR1422400 are gratefully acknowledged.

Notes

*The Nu _t Diff. is the difference of Nu _t between ϵ = 0 and ϵ = 1 under the same Ra.

**The Nu _c Diff. is the difference of Nu _c between ϵ = 0 and ϵ = 1 under the same Ra.