The Measurement of Natural Convective Heat Transfer in Triangular Enclosures

Heat transfer rates were experimentally measured for laminar convection air flows in two-dimensional triangular enclosures with two side walls which were heated and cooled and an adiabatic bottom. Both local and overall heat transfer data were obtained by the use of a Wollaston prism schlieren interferometer. The angle between the two isothermal side walls was varied between 60 and 120 deg, which resulted in a variation in aspect ratio (enclosure height/base width) between 0.29 and 0.87, while the Grashof number was varied between 2.9 × 10⁶ and 9.0 × 10⁶. Results are compared to previously obtained isothermal inclined flat plate data and rectangular enclosure data. Present results agree with rectangular enclosure results. One deviation from local rectangular enclosure data was found in the apex regions of the triangular enclosures, where complex thermal and flow interactions occurred due to proximity of the two side walls.