Multigrid aircraft computations using the OPlus parallel library*

Abstract

This paper presents the OPlus library which is a exible library for distributed memory parallel computations on unstructured grids through the straightforward insertion of simple subroutine calls. It is based on an underlying abstraction involving sets, pointers (or mappings) between sets, and operations performed on sets. The key restriction enabling parallelisation is that operations on a particular set can be performed in any order.The set partitioning, computation of halo regions, and the exchange of halo data as required is performed automatically by the OPlus library after the user speci es the sets and pointers. A single source OPlus application code can be compiled for execution on either a parallel or a sequential machine, greatly easing maintainability of the code.The capabilities of the library are demonstrated by its use within a program for the calculation of inviscid ow over a complete aircraft using multigrid on a sequence of independent tetrahedral grids. Good computational e ciency is achieved on an 8-processor IBM SP1 and a 4-processor Silicon Graphics Power Challenge.

A moving mesh algorithm for aero‐thermo‐mechanical modelling in turbomachinery

“…In the context of the computational efficiency, an important issue is the choice of a good preconditioner for the conjugate gradient method, as recently confirmed in the study of Markou et al . In our work, the method was integrated within a CFD code, using the existing data structure and parallel framework Oxford Parallel Library for Unstructured Solvers (OPLUS) . Therefore, the parallelisation of the method has been subjected to the restrictions imposed by the OPLUS library.…”

Detecting Scale-Induced Overflow Bugs in Production HPC Codes

“…This not only allows application experts to focus on their problem domain but also opens the possibility for significant impact through optimisations to the OPlus framework benefiting the whole ecosystem of OPlus programs. The library has been applied to real world problems, for example Crumpton et al [7] show results obtained using a multigrid solver parallelised with OPlus to perform aerodynamic calculations of an aircraft and it has been used in developing industrial CFD codes [16]. The success of this approach has led to the development of a follow on OP-DSL effort [3] which will be the focus of future work.…”

Mesh motion approach based on spring analogy method for unstructured meshes

“…Mesh motion strategy is one of the key points in this kind of problems. Already several mesh motion strategies for the dynamic mesh have been developed and show good results for problems with small amplitude oscillation and deformation [2][3][4][5][6] . However, these methods are still far from being a maturing subject for geometrically complex and largely moving and deforming body problems.…”