The effects of thermal radiation upon the laminar free convection boundary layer of a vertical flat plate were studied for absorbing and nonabsorbing gases. Experimental velocity and temperature profiles were obtained for a constant heat flux boundary condition in air and CO2 and these are compared to analytical calculations for optically thin gases and absorbing gray gases. A correlation is presented by which plate surface temperatures as a function of plate emissivity for optically thin gases may be predicted for use in determining the convective heat transfer through standard non-radiative film heat transfer correlations.

The stress intensity factor for a semicircular edge crack is derived. Numerical values for axial, bending, and thermal loads in half spaces and plates are presented. The results show that a magnification of the stress intensity factor of about 20 percent occurs at the free surface.

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Natural convection in a square enclosure with heated vertical walls and temperature-dependent conductivity and viscosity was simulated for Prandtl numbers ranging from 0.01 to 1.0 and Ra ≤ 106. Although the variable properties produced observable changes in the the temperatures and velocities, the overall heat transfer, as represented by the Nusselt number, was found to be unaffected and was accurately correlated in terms of the Rayleigh and Prandtl numbers using Nu=0.185Ra00.278Pr00.089 with properties evaluated at the average temperature. This correlation applies to both isothermal and constant heat flux hot walls.

An expression is developed for the stress intensity factor of a penny-shaped crack in an infinite elastic solid subjected to nonaxisymmetric normal loading. The stress intensity factor can then be determined for penny-shaped cracks in infinite or finite solids subjected to symmetric loading about the plane containing the crack. The singular state associated with the embedded crack with finite, nonaxisymmetric normal loading is that of plane strain. Results are also presented for two problems: A penny-shaped crack subjected to two symmetrically located concentrated forces and a penny-shaped crack in a large beam subjected to pure bending.