component. The behavior of real surfaces at large angles of incidence would be of extreme interest in view of off-specular peaks which have been studied by Torance, Sparrow, and Birkebak, e.g., Ref. 5. The significant point to be made is that photon-induced forces cannot be predicted satisfactorily for real surfaces that have combined diffuse and specularly reflecting properties by using ideal reflectance models. Lastly, a few remarks are in order on possible changes in the result for solar energy that could be experienced if experimental reflectance data were available to permit relaxation of the assumption that reflection occurs only in the plane of incidence. The same total reflected energy is assumed as follows: 1) Diffuse model. Pz and Py would be zero and Px would not be changed in magnitude. 2) Specular model. By definition of pure specular reflection, there would be no change in results and Py = 0. 3) Real surface model. The general trend would be to increase the diffuse characteristics of the reflected energy. Assuming the same orientation of axes and a reflection func-

Heat transfer from a viscous nongray radiating shock layer.

Ionization fraction as independent variable in plasma transport correlation, noting role in pressure effect increase

E. J. Roschke

Papers

Plasma-transport property correlation using ionization fraction.

End-wall pressure distributions in a confined vortex.