細管中の粘性流動による発熱と試料の温度上昇

抄録

The viscous heat effect on the fluid temperature is investigated in circular tube flow. Approximate mathematical solutions are given for the temperature distribution of fluid over the cross section of a circular tube and also for the temperature rise of fluid along the tube in consideration of heat conduction through the tube wall.
In the case of liquid flow, the temperature rise ΔT at the exit of the tube is related to the pressure drop Δp through the tube by the following approximate equation. _??_, where _??_, a: internal radius of tube b: external radius of tube l: length of tube K_c: thermal conductivity of tube K_f: thermal conductivity of liquid c: volumetric heat capacity of liquid η: viscosity of liquid. The temperature rises calculated by this equation generally agree with those obtained by experiments.
In the case of gaseous flow where the sample gas is regarded as an ideal gas, it is concluded theoretically that the heat energy due to viscous resistance is spent in compensation for the reduction of internal energy due to the bulk expansion of flowing gas with the decrease of pressure, and consequently, temperature of flowing gas is kept constant.