6 - Practice of Dissipative Particle Dynamics Simulations

Abstract

This chapter analyzes an alternative microsimulation method called the dissipative particle dynamics (DPD) method, which is available for simulating a particle suspension system. In the DPD method, the fluid is assumed to be composed of virtual fluid particles called ‘dissipative particles,’ and therefore the solution of a flow field can be obtained from the motion of the dissipative particles in a way similar to the molecular dynamics method. A significant advantage of this method is that when it is applied to the simulation of a particle suspension, the multibody hydrodynamic interaction is taken into account without introducing a special technique. This characteristic of the DPD method provides it with a great potential as a simulation tool for particle suspensions; the present method is thus available for various fields of scientific research, including the pharmaceutical sciences and specialized engineering fields. An exercise is provided to discuss the feasibility of the DPD method for successfully capturing the aggregate formations of the magnetic particles, which are dependent on the strength of magnetic particle–particle interactions. In the present demonstration, the applied magnetic field is assumed to be very strong, so that only the translational motion of magnetic particles needs to be considered. The rotational motion may be neglected. The sample simulation program is written in the FORTRAN programming language at the end of the exercise.