The Lattice-Boltzmann Method for the approximate solution of the Navier-Stokes equations has become an interesting alternative to classical finite volume based discretization methods. Because the flow domain is not meshed in the classical sense but only voxelized and geometrically complex boundaries can be introduced in an easy form by bounce-back or off-Lattice boundary conditions, the method lends itself very well to simulations of channel flows inside hydraulic components. In this paper, a flow problem in a single acting cylinder attached to a 3/2 directional spool valve is used as a benchmark problem. The Lattice-Boltzmann simulation is used to generate a reference solution for the pressure step response of the blocked cylinder with superimposed wave propagation. From this reference data set, a non-parametric frequency domain input-output model is extracted and compared with results from classical lumped parameter modeling.
Keywords: Lattice-Boltzmann method, fluid power systems modeling