Browse > Article

Numerical Analysis of Optimum Air-Layer Thickness in a Double Glazing Window  

Hwang Ho June (Department of Mechanical Engineering, Seoul National University of Technology)
Choi Hyoung Gwon (Department of Mechanical Engineering, Seoul National University of Technology)
Publication Information
Korean Journal of Air-Conditioning and Refrigeration Engineering / v.17, no.2, 2005 , pp. 191-199 More about this Journal
Abstract
Double pane window system, in which an air layer with a finite width is filled between glasses, is used in order to increase the insulation efficiency. In the present study, a conjugate heat transfer problem of a double pane window system has been studied numerically in order to investigate the effect of an air layer on the heat transmittance of the double pane window system using a finite element method based on P2P1 basis function. In this study on the conjugate heat transfer of a double pane window system, numerically predicted Nusselt numbers with or without conjugate heat transfer effect have been compared with an available existing empirical formula. It has been found that a Nusselt number from an existing formula for an enclosed space is different from that obtained from the present conjugate heat transfer analysis mainly due to the effects of a very high aspect ratio and conjugate heat transfer mechanism. Furthermore, it has been shown that the numerically estimated optimal air thickness of the double pane window system with conjugate heat transfer effect is a little bit longer than that obtained without considering conjugate heat transfer effect.
Keywords
Conjugate Heat Transfer; Double Pane Window; Optimum Air-Layer Thickness;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Gan, G., 2001, Thermal transmittance of multiple glazing: computational fluid dynamics prediction, Applied Thermal Engineering, Vol. 21, pp. 1583-1592   DOI   ScienceOn
2 Larsson, U., Moshfegh, B., and Sandberg, M., 1999, Thermal analysis of super insulated windows (numerical and experimental investigations), Energy and Buildings, Vol. 29, pp. 121-128   DOI   ScienceOn
3 Dong, S.-F. and Li, Y.-T., 2004, Conjugate of natural convection and conduction in a complicated enclosure, International Journal of Heat and Mass Transfer, Vol. 47, pp. 2233-2239   DOI   ScienceOn
4 De Vahl Davis, G., 1983, Natural convection of air in a square cavity a bench mark numerical solution', Int. J. Num. Meth. Fluids, Vol. 3, pp. 249-264   DOI   ScienceOn
5 Choi, H. G., Choi, H., and Yoo, J. Y., 1997, A fractional 4 step finite element formulation of the unsteady incompressible Navier-Stokes equations using SUPG and linear equal-order element methods, Comput. Method. Appl, Engrg., Vol. 143, pp. 333-348   DOI   ScienceOn
6 Misra, D. and Sarkar, A., 1997, Finite element analysis of conjugate natural convection in a square enclosure with a conducting vertical wall, Comput. Methods Appl. Mech. Engrg, Vol. 141, pp. 205-219   DOI   ScienceOn
7 Aydin, O., 2000, Determination of optimum air-layer thickness in double pane windows, Energy and Buildings, Vol. 32, pp. 303-308   DOI   ScienceOn
8 Hwang, H.-J., and Lee, K.-H., 2001, A study on the change of heat transmission coefficient according to the degree of windows slope, Journal of Korean Housing Association, Vol. 12, pp. 133-140
9 Yoo, J. Y. and Choi, H. G., 2003, PAT-Flow, Program registration number 2003-01-12- 1139
10 MacGregor, R. K. and Emery, A. P., 1969, Free convection through vertical plane layer : moderate and high prandtl number fluid, J. Heat Transfer, Vol. 91, pp. 391   DOI
11 Jang, D. S., Song, E.-Y., and Lee, S.-I., 1992, A numerical and experimental study of heat transfer through a double pane window to enhance thermal insulation of building, Energy Engg. J., Vol. 1, pp. 66-75