Experimental visualization of natural convective flow was carried out by using several kinds of fluid contained in a narrow vertical rectangular cavity with one vertical wall heated, the opposing vertical wall cooled and the upper and lower walls insulated. The effects of the Prandtl number Pr of the working fluid and the width of the cavity W on the flow pattern are discussed qualitatively in the present paper. The occurrence of flow patterns consisting of unicellular flow, steady secondary flow, tertiary flow and transition (from laminar to turbulent) flow is categorically demonstrated by the photographs taken. Moreover, experimental measurements of the net heat transfer through the vertical fluid layer are given for aspect ratios of 6-30 and Prandtl numbers of 4-12 500.

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Experiments to measure the heat transfer characteristics for various cavities situated at a duct-wall were performed. Flow visualization, measurements of pressure and temperature distributions on the heated bottom surface of cavity were carried out. It was observed that the effects of main flow stream, reattachment of separated flow, and vortex flow in the cavity on heat transfer unexpectedly large. It was found that heat transfer did not always decrease monotonously with an increase of aspect (depth-width) ratio D/W, in the flow range of laminar to turbulent. Correlations between Num and Rew were made in laminar and turbulent heat transfer ranges.

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Experiments have been performed to investigate the ice-formation phenomena and the heat transfer characteristics for water flow between two horizontal parallel plates. The experiments were carried out under the condition that the upper and lower plates were cooled at the same uniform temperature, which was less than the freezing and the temperature of the water. The temperature of the plates ranged from −7 to −14°C with inlet-water temperature varied from 2 to 5°C. The cooling-temperature ratio θc ranged from 1.4 to 7.0. By using three different values of height H, 16, 30, and 40 mm between the horizontal parallel plates, the Reynolds number ReH were varied from 3.8 × 103 to 3.2 × 104. As a result of the present investigation, two different types of ice-formation were observed. One was transition ice-formation type, and the other was smooth ice-formation type. It was found that the transition ice-formation type occurred for ReH/θc0.741 < 104, while the smooth ice-formation type occurred for ReH/θc0.741 > 104. The relation equations for the ice-transition position and the heat transfer coefficients along the water-ice interface were extensively determined.