Thermal partition of two asymmetric discrete heat sources by cold air curtain

Abstract

A partition solution implemented by a cold air curtain for two asymmetric discrete heat sources in a two-dimensional rectangular enclosure was numerically studied. Main attentions were focused on the effects of Reynolds number, Grashof number, separation distance between heat sources, and buoyancy ratio. It is found that the airflow and heat transfer are not only determined by governing parameters, but also affected by boundary conditions. It is also found that nearly symmetry of flow structure corresponds to nearly thermal partition, and the symmetry can be enhanced when Reynolds number, separation distance and buoyancy ratio increase. In addition, it is observed that there is a minimum Reynolds number for obtaining nearly thermal partition, which increases when Grashof number increases.

Keywords

cold air curtain / asymmetric discrete heat sources / critical partition Reynolds number / mixed convection

References

[1] DengQi-hongModeling and characteristics of indoor air convection [D], 2003, Changsha, College of Civil Engineering, Hunan University(in Chinese)

[2] AungW, WorkuG. Developing flow and flow reversal in a vertical channel with asymmetric wall temperatures [J]. J Heat Transfer, 1986, 108: 299-304

[3] AungW, WorkuG. Mixed convection in ducts with asymmetric wall heat fluxes [J]. J Heat Transfer, 1987, 109: 947-951

[4] El-DinM M S. Effect of thermal and mass buoyancy forces on the development of laminar mixed convection between vertical parallel plates with uniform wall heat and mass fluxes [J]. Int J Thermal Science, 2003, 42: 447-453

[5] NieldD A. Forced convection in a parallel plate channel with asymmetric heating[J]. Int J Heat and Mass Transfer, 2004, 47: 5609-5612

[6] StriblingD, TassouS A, MarriottD. A two-dimensional computational fluid dynamic model of a refrigerated display case [J]. ASHEAE Trans, 1997, 103: 88-94

[7] MhiriH, GolliS E I. Numerical study of the thermal and aerodynamic insulation of a cavity with a vertical downstream air jet [J]. Int Comm Heat Mass Transfer, 1998, 25: 919-928

[8] ChenYun-guang, YuanXiu-ling. Simulation of a cavity insulated by a vertical single band cold air curtain [J]. Energy Conversion and Management, 2005, 46: 1745-1756

[9] GeY T, TassouS A. Simulation of the performance of single jet air curtains for vertical refrigerated display cabinets [J]. Applied Thermal Engineering, 2001, 21: 201-219

[10] NavazH K, FaramaR. The application of advanced methods in analyzing the performance of the air curtain in a refrigerated display case [J]. J Fluid Engineering, 2002, 124: 756-764

[11] WuYe-zheng, XieGuo-zhen, ChenZhong-qi, et al.. An investigation on flowing patterns of the airflow and its characteristics of heat and mass transfer in an island open display cabinet with goods [J]. Applied Thermal Engineering, 2004, 24: 1945-1957

[12] DengQi-hong, TangGuang-fa. Special treatment of pressure correction based on continuity conservation in pressure based algorithm [J]. Numer Heat Transfer B, 2002, 42: 73-92