A sliding interface method for unsteady unstructured flow simulations

Abstract

SUMMARYThe objective of this work is to develop a sliding interface method for simulations involving relative grid motion that is fast and efficient and involves no grid deformation, remeshing, or hole cutting. The method is implemented into a parallel, node-centred finite volume, unstructured viscous flow solver. The rotational motion is accomplished by rigidly rotating the subdomain representing the moving component. At the subdomain interface boundary, the faces along the interface are extruded into the adjacent subdomain to create new volume elements forming a one-cell overlap. These new volume elements are used to compute a flux across the subdomain interface. An interface flux is computed independently for each subdomain. The values of the solution variables and other quantities for the nodes created by the extrusion process are determined by linear interpolation. The extrusion is done so that the interpolation will maintain information as localized as possible. The grid on the interface surface is arbitrary. The boundary between the two subdomains is completely independent from one another; meaning that they do not have to connect in a one-to-one manner and no symmetry or pattern restrictions are placed on the grid. A variety of numerical simulations were performed on model problems and large-scale applications to examine conservation of the interface flux. Overall solution errors were found to be comparable to that for fully connected and fully conservative simulations. Excellent agreement is obtained with theoretical results and results from other solution methodologies.

Predicting Unsteady Loads in Marine Propulsor Crashback Using Large Eddy Simulation

“…Data exchange between the grids can be performed only at the sliding interface so that no remeshing, deformation, or hole cutting is required. The sliding interface method has been developed on multiblock structured grids [18,19] and on unstructured grids [20,21], and is popular to handle relatively rotationg grid systems and on unstructured grids.…”

Enhancing performance and scalability of data transfer across sliding grid interfaces for time-accurate unsteady simulations of multistage turbomachinery flows

“…These methods employ the halo cells extruded into the opposite side of the interface. This strategy is followed in [14,17] and is also implemented in the Hydra code [18]. For each change in relative position of the sub-domains, the sliding plane procedure goes through the following phases:…”

“…Their relative motion can be described by a rotation or a translation along some surfaces of revolution or planes. These methods are called the sliding mesh techniques [13,14,15,16,17].…”

A finite volume algorithm based on overlapping meshes for simulation of hydrodynamic problems

“…To discretise the convection term, it can be approximated as below: (6) where f i u − is calculated using Gamma interpolation based on definitions of Normalized Variable Diagram (NVD) [10] .…”

“…Also, there are a wide variety of methods to deal with rigid body motions in the domain which are body-attached/moving mesh [3] , deformable mesh [4] , re-mesh [5] , sliding mesh [6] , overlapping mesh [7] , Cartesian mesh [8] . Overlapping mesh system is the base of current algorithm.…”