Effects of Semitransparent Window AspectRatio on Interaction of Collimated Beam withNatural Convection: Part I

Abstract

The effects of the semitransparent winodw's aspect ratio on the interaction of the collimated beam with natural convection have been investigated numerically in the present work. The combination of geometrical parameters of the semitransparent window, i.e., height ratio (h r ) and window width ratio (w r ) and Planck numbers of the medium have been considered. The other parameters, like flow parameter (Ra= 10 5 ), fluid parameter (Pr=0.71), thermal parameter (N), Irradiation (G=1000 W /m 2 ), Angle of incidence (φ = 135 0 ) and geometrical parameter of the geometry (A r =1) and the wall conditions have been kept constant. A collimated beam is irradiated with irradiation value (G=1000 W /m 2 ) on the semitransparent window at an azimuthal angle (φ)135 0 . The cavity is convectively heated from the bottom with heat transfer coefficient 50 W /m 2 K and free stream temperature 305 K. A semitransparent window is created on the left wall and isothermal conditions (T=296 K) is applied on the semitransparent, left and right vertical walls, wherein adiabatic conditions are applied on upper wall of the cavity. The dynamics of two vortices inside the cavity change considerably by combinations these semitransparent window's aspect ratio and Planck number (Pl) of the medium. The left vortex breaks into two parts and remains confined in upper and lower left corners for some combination of aspect ratios and Planck numbers of the medium. The thermal plume flickers depending on the situation of dynamics of two vortices inside the cavity. The localized hating of the fluid happens mostly for large height ratio of semitransparent window. The conduction; radiation and total Nusselt number are also greatly affected by the semitransparent window's aspect ratio and the Planck number of the medium.