ABSTRACT
The major criterion in determining whether gas flow in a channel requires special consideration in its analysis is the Knudsen number. Small velocities and high-pressure gradients due to large wall shear stresses were noticed as characteristics of microscale gas flow. The idea of utilizing the high heat transfer capability of phase change phenomena in the cooling of substrates has been of great importance ever since microscale heat transport became the focus of attention of investigators. The flow and temperature fields are coupled, and the analysis of the problem involves simultaneous solution of the continuity, momentum, and the energy equations with appropriate boundary conditions. The major difficulty encountered in making measurements in microscale systems is the introduction of probes. This becomes extremely difficult in the case of channels. The temperature distribution is used to calculate the surface heat transfer coefficients and the local Nusselt number values, for a constant heat flux application at the heater.
