Transient numerical simulation of multiple pane windows filling with radiating gas

摘要

This work deals with parametric study of transient fluid flow and heat transfer characteristics in double and triple pane windows, while the filling gas in considered as a participating medium. The momentum and energy equations in the filling gas combined with conduction equation in the glass sheets are solved simultaneously as a conjugate heat transfer problem. The mechanism of heat transfer in the gas phase is combined natural convection and radiation. The gas radiation is calculated by solving the radiative transfer equation (RTE) using the discrete ordinates method (DOM). The computations are validated against the experimental and numerical data in literature and excellent consistency is found. The main contributions of this study are twofold. First, the effect of gas optical thickness on flow and thermal characteristics of double and triple pane windows is investigated. Second, the performances of these windows in transient condition are compared. The numerical results show that in large values of optical thickness, multicellular flow forms inside the gas layers which leads to periodic heat flux on the window surface.