Springer Online Journal Archives 1860-2000
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Abstract The problem of modelling turbulence in CFD is due to the wide range of length scales present in a turbulent flow. The physics of these scales is examined, and the need for models of the small scale motions is made clear. A review is given of methods of turbulence modelling. These methods can be divided into two classes: Reynolds averaged Navier–Stokes (RANS) models, and large eddy simulation (LES). The Reproducing Kernel Particle method (RKPM) is then presented and proposed as a class of filters for LES of inhomogeneous turbulent flows. Important properties of the method are discussed, including the effectiveness of the RKPM reproduction as a low-pass filter. The commutation of the filtering operation with differentiation is demonstrated, showing that the commutation error can be made arbitrarily small. A one-dimensional non-linear example problem is solved using a Galerkin method in which a bi-scale constitutive model is used for the subgrid scale terms. The extension of the method to the three-dimensional equations of fluid dynamics is then outlined, where the method is used as a filter in a dynamic subgrid stress model. Emphasis is placed on the multi-scale properties of RKPM, which allow the reproduction of different scales of the solution using the same set of nodal parameters.
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