Maximum temperature in a lubricant, oil is acting as a lubricant for a pair of cylindrical surfaces such as those shown in Fig. 10.4-1. The angular velocity of the outer cylinder is 7908 rpm. The outer cylinder has a radius of 5.06 cm, and the clearance between the cylinders is 0.027 cm. What is the maximum temperature in the oil if both wall temperatures are known to be 158°F? The physical properties of the oil are assumed constant at the following values: 

Viscosity                                    92.3 cp 

Density                                      1.22 g/cm³ 

Thermal conductivity              0.055 cal/s ∙ cm ∙ C

Substance" (Pa.s) Air Chlorine .351 10-5 k(W/m-K) CP (J/kg-K) 1.854 x 10 2.614 102 1.001 x 10 4798 102 8.960 x 10-3