Velocity distribution of water molecules in pores under microwave electricfield

In order to understand the transport of water in pores under the influence of a microwave electric field the velocity distribution function of the wat er molecules is thought to be a key quantity. First, bulk water under the i nfluence of an alternating electric field is studied by using a kinetic equ ation. As rotation occurs on a faster time scale and translation on a slowe r time scale it is argued that the velocity distribution for the bulk water is a Maxwell-Boltzmann distribution. Next, the non-equilibrium molecular d ynamics simulation method is applied to study the behaviour of TIP3P water molecules under microwave electric field in a slit pore with thermostated w alls. The water heats up till it reaches a steady state temperature. It is found that in the transient process as well as in the steady state the velo city distribution function is a Maxwell-Boltzmann distribution for the corr esponding temperature. Hence, there is no convective mass transport due to a direct influence of the electric field. (C) 2001 Editions scientifiques e t medicales Elsevier SAS.