Analytical Solution of the Thermal Entrance Heat Transfer Problem for Viscous Flow in Annulus

摘要

The Graetz-Nusselt problem with Brinkman extension is considered for steady-state laminar Newtonian flow in annuli. To solve the problem, a separation of variables method is used. In the limiting cases, the eigenvalues are in full agreement with the eigenvalues corresponding to flat channel and circular pipe. Useful formulas are represented to calculate the length of the thermal entrance region and Nusselt numbers in annuli.