Measurements of the thickness and the stability of thin films of liquid (1–150 μmthick) formed on a rotating horizontal disk are presented and correlated in terms of an asymptotic-expansion solution of the thin-film equations. Water, various alcohols and water with wetting activities were used to cover a range of viscosity (1-2.5cP) and surface tension (20-72 dynes/cm). Smooth flow was found to occur in a region defined by the flow rate, rotational speed and physical properties of the liquid. Outside this region various wave patterns were observed (concentric, spiral and irregular waves). A linear theory of the stability of the film based on an extension of classical stability theories for plane films on inclined planes is given and contrasted with the experimental results. Surface phenomena associated with the use of wetting agents were found to have a strong effect on the stability of the film.

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This paper considers the convective heat-transfer characteristics of the flow in the annular gap between a rotating inner cylinder and a stationary outer cylinder. Heat-transfer measurements are reported for two gap sizes and various combinations of axial and rotational flows. Both smooth and slotted surfaces were used. Measurements for laminar and turbulent-flow conditions followed the trends predicted by theory. An unusual feature of the results for rotational flow without axial flow is the heat-transfer rate in an intermediate flow region existing between the laminar and turbulent regimes. Here, regular ring-shaped vortexes cause a heat-transfer rate even greater than with turbulent flow.

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The problems of penetrating a planetary atmosphere are reviewed and techniques for penetration are discussed. These techniques are resolved into two general classes: (1) Gradual entry into the atmosphere with relatively low deceleration loads and heating rates low enough so that the heat may be rejected by thermal radiation from the surface; and (2) direct entry with higher deceleration loads and higher heating rates with the heat being absorbed by the body surface.

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