Solution for Transient Conjugated Forced Convection in the Thermal Entrance Region of a Duct With Periodically Varying Inlet Temperature

This work presents an analytical solution of the transient conjugated laminar forced convection problem of a slug flow in the thermal entrance region inside a parallel plate duct. A solution in series form is already known for this kind of problem. This solution leads to a complex eigenvalue problem with transcendental equations. The present solution obtained by using the Laplace transform completely eliminates this problem. The amplitudes and phase lags with respect to the inlet conditions are determined for the complex wall temperature, fluid bulk temperature, and wall heat flux from this solution. The results are plotted for comparison with the results obtained with the series solution.