Lay Down Simulation of Viscoelastic Fluids Using the Hybrid Immersed-Boundary Method

Paper in proceeding, 2016

Lay down of viscoelastic fluids is common in several manufacturing processes. In the automotive industry, sealing material is sprayed onto the vehicle body to prevent water leakage into cavities and to reduce noise. To predict the deposition and lower the environmental impact by reducing material consumption, a detailed physical understanding of the process is important. In this work the resulting surface multi-phase flow is modeled and simulated in IBOFlow, the in-house multi-phase flow solver at the Fraunhofer-Chalmers Centre. In the solver the two phase flow is modelled by the volume of fluid method and the viscoelastic fluid by a general Carreu rheology model. In the solver the scanned or CAD geometry is handled by the hybrid immersed boundary method and the material interface is resolved by the adaptive anisotropic octree grid. The resulting hanging octree and triangular nodes along the geometry are automatically handled by the immersed boundary method. To boost the computational performance the simulation domain is in a novel way dynamically divided into an active and an inactive part. The governing equations are only assembled and solved for in the active part, which is determined by the local position of the injection nozzle. The interface between the active and the inactive cells are handled by symmetry boundary conditions and the pressure is always set for a point inside the active domain. The sealing lay down simulation is successfully validated for a number of real sealing beads on a plate and on a Volvo V40 vehicle. Finally, the importance of resolving the nozzle in the simulation is investigated for a static case.