N R e G = superficial gas Reynolds number N R e L = superficial liquid Reynolds number R = pipe radius, in. 0, 00 z 8 = film thickness, in.8 p L = liquid density, lb./cu.ft. Subscripts and Superscripts exp pie 1 = coordinate position 2 bar tick = axial velocity of the film, ft./sec. = circumferential velocity of the film, ft./sec. = coordinate direction parallel to the pipe axis positive direction is downstream, in. = angular direction, 0 deg. at the top of the pipe, 180 deg. at the bottom of the pipe, deg. or rad. = experimentally determined value of a variable = value of a variable calculated from a proposed model = coordinate position where 2 is greater than 1 = average value of a variable with respect to a co-= instantaneous value of a variable ordinate direction LITERATURE CITED1. Alexander, L. G., and C. L. Coldren, Ind. Eng. Chem., 43, 1325 (1951).