Natural convection in rectangular air enclosures of aspect ratio less than one

Natural convection heat transfer in rectangular air enclosures of aspect ratio between 0.1 and 1.0 for the Grashof number range of 1,000,000 to 30,000,000 was investigated both experimentally and numerically. Steady two dimensional laminar natural convection in these enclosures was analyzed using finite difference techniques. The heat transfer rates across the enclosures were measured interferometrically for the isothermal enclosure and the foam enclosure. Horizontal and vertical velocities within the enclosures were measured with a laser Doppler anemometer. The flow patterns within the enclosures were visualized by backlighting the enclosure with laser light and injecting cigarette smoke into the enclosure.