Numerical Simulation of Steady-State Conjugate Heat Transfer in a Circular Microtube inside a Rectangular Substrate

ABSTRACT

The steady-state heat transfer for laminar flow inside circular microtubes within a rectangular substrate has been investigated. The Reynolds number, Prandtl number, thermal conductivity ratio, and diameter ranges were 1,000–1,900, 6.78–12.68, 27–2,658, and 300–1,000 μm, respectively. Near the entrance, the local Nusselt number varied significantly along the tube periphery. The maximum temperature of the substrate and the outlet temperature of the fluid decreased as the Reynolds number increased. The peripheral average Nusselt number increased with increase of Reynolds number, Prandtl number, solid-to-fluid thermal conductivity ratio, and tube diameter-to-wafer thickness ratio. A correlation for peripheral average Nusselt number was developed.

This research was partly funded by the National Aeronautics and Space Administration (NASA) under Grant NAG3-2751.