Evaporative Microchannel Cooling: An Atomistic Approach

Heat generation and temperature rise in electronic devices is a technical problem with increasing importance, since the number of transistors per surface area on integrated circuitries is rapidly increasing. If the heat cannot effectively be carried away damage in the circuitry may occur. Therefore enhanced and integrated cooling is needed. A promising technique is evaporative microchannel cooling. However, a major problem in modeling such micro-device is that the continuum approach starts to fail in the vapor phase and more detailed modeling becomes necessary. Since on these small scales the boundary and interface conditions are very important for the overall performance of the device, we choose the approach in which we start with understanding the essential physical phenomena at a molecular level. In this paper a detailed particle-based model is derived for these interactions: local interactions between the three phases are studied by molecular dynamics (MD) simulations in a detailed way. In this way physically and thermodynamically correct interface and boundary conditions (e.g. slip velocities and temperature jumps) are ensured. Finally, the enhanced heat transfer in the evaporative zone (Argon on a Calcium surface) is simulated by our molecular model and is compared to the results obtained by the continuum microregion model developed by P. Stephan et al. (Int. J. Heat Mass Transfer, 35, pp. 383–391, 1992).