Coupling continuum to molecular-dynamics simulation: Reflecting particle method and the field estimator

We propose a method to induce microchannel (Poiseuille) flow in a molecular-dynamics simulation by introducing a partially reflecting ``membrane'' as a means of driving the fluid flow while conserving particle number and total energy. We also develop a method to estimate various continuous macroscopic fields from particle data, based on maximum likelihood inference. A general statistical approach is discussed for coupling the continuum with molecular-dynamics simulation with emphasis on minimal disturbance to particle dynamics, which is to be fully developed later.