Turbulence modelling for meshfree collocation methods

  • Padmanabha, Mohan (ITWM Fraunhofer)
  • Kuhnert, Jörg (ITWM Fraunhofer)
  • Gauger, Nicolas R (University of Kaiserslautern-Landau (RPTU))
  • Suchde, Pratik (University of Luxembourg)

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Lagrangian meshfree methods are becoming a popular alternative to classical mesh-based methods. A major advantage of meshfree approaches is the possibility of avoiding the tedious and time-consuming process of mesh generation, which becomes especially relevant for complex geometries. There are numerous meshfree Lagrangian methods proposed in literature. In the present work, the method used is based on Generalized Finite Difference Method (GFDM)[1,2]. The method uses a strong formulation, and has been widely applied to continuum mechanics as well as fluid mechanics problem. Many relevant applications include flow with high velocities, which brings turbulent phenomenon into picture. Turbulence is a major physics research field with an enormous amount of research being done, especially in the context of mesh-based methods. However, with respect to meshless methods, the research and developments are still in an early stage. The novelty of this work is mostly on development of methods to incorporation the turbulence models based on eddy viscosity model in a meshfree collocation framework. The turbulence models that are considered are the one equation Spalart Allmaras model[3] and 2 equation k-ω model[4]. The focus here is to be able to solve both low and high Reynolds number flows. The incorporated turbulence models are used to solve three different basic simulation cases, flow over a flat plate, flow around a wing and free flow jet which might cover major turbulent phenomenon. The results are validated against both the experimental and numerical results. Different wall treatment methods are also considered, and the effect of these treatment are studied to evaluate the efficiency of the methods and accuracy of the results. In this talk, we will highlight the challenges arising in incorporating standard turbulence models into a meshfree framework. Emphasis will be made on the handling of boundary conditions, and wall-layer points.