SPH modelling of hydrodynamic lubrication: laminar fluid flow–structure interaction with no-slip conditions for slider bearings

The FOSS CFD-SPH code SPHERA v.9.0.0 (RSE SpA) is improved to deal with “fluid–solid body” interactions under no-slipconditions and laminar regimes for the simulation of hydrodynamic lubrication. The code is herein validated in relation to auniform slider bearing (i.e. for a constant lubricant film depth) and a linear slider bearing (i.e. for a film depth with a linearprofile variation along the main flow direction). Validations refer to comparisons with analytical solutions, herein generalizedto consider any Dirichlet boundary condition. Further, this study allows a first code validation of the “fluid–fixed frontier”interactions under no-slip conditions. With respect to the most state-of-the-art models (2D codes based on Reynolds’ equationfor fluid films), the following distinctive features are highlighted: (1) 3D formulation on all the terms of the Navier–Stokesequations for incompressible fluids with uniform viscosity; (2) validations on both local and global quantities (pressure andvelocity profiles; load-bearing capacity); (3) possibility to simulate any 3D topology. This study also shows the advantages ofusing a CFD-SPH code in simulating the inertia and 3D effects close to the slider edges, and it opens new research directionsovercoming the limitations of the codes for hydrodynamic lubrication based on the Reynolds’ equation for fluid films. Thisstudy finally allows SPHERA to deal with hydrodynamic lubrication and improves the code for other relevant applicationfields involving fluid–structure interactions (e.g. transport of solid bodies by floods and earth landslides; rock landslides).SPHERA is developed and distributed on a GitHub public repository.