We are developing computational and simulation tools to provide an in-depth understanding of the thermodynamic and dynamic properties of suspensions of nonmagnetic particles immersed in magnetic fluids. A fundamental understanding of these properties is important in the development of magnetic separation systems. The trajectories of magnetic particles in a modified rhombic multi-wire array are simulated in a combined magnetic and flow field. The magnetic field in the array is calculated by taking superposition of single wires and the flow field is obtained by interpolation of a numerical solution of the Navier-Stokes equation. We have explored the effect of the magnetic field on the nonmagnetic particles. The methods and conclusions presented here can be extended to novel magnetic separator design and help us understand the entire separation process.