Heat transfer rates of both heating and cooling for dissociating nitrogen dioxide gas were experimentally measured under turbulent pipe-flow conditions. The range of the average Reynolds numbers for which these measurements were made was from 6,700 to 22,000. Thermal flux at the inside surfaces of the tubes ranged from 300 to 8,400 B.t.u./hr.-sq. ft. for heating and cooling. Wall temperatures of the heater section were varied from 100° to 400°F. and those of the cooler section were varied from 70° to 140°F. Mixed mean bulk gas temperatures for both heating and cooling were in the range 72° to 190°F. Radial velocity and temperature profiles were measured at various longitudinal positions in the heater section.

For this equilibrium gas mixture heat transfer coefficients as high as 14 times those for the gas under frozen equilibrium conditions were obtained. Correlations which should be generally applicable to equilibrium reacting systems have been determined from the experimental data.