Abstract
Transient heat-conduction solutions are used to determine the thermal characteristics of fluid flowing in circular conduits, annuli, and between parallel plates. Jaeger’s method of deriving the time lag for heat conduction in composite slabs (herewith extended to include composite cylinders) reduces the problem to a series of arithmetical calculations. Numerical results are presented for flow between parallel plates with the following boundary conditions: Constant heat rate, linear wall-temperature variation, and constant wall temperature at one of the external surfaces with constant heat rate, no heat transfer, or zero temperature at the other surface. Some solutions are extended to account for external wall resistance, and thermal entry lengths are evaluated for fluids with high or low Prandtl numbers.
