资源描述
Kliknij,aby edytowa styl wzorca tytuu,Kliknij,aby edytowa style wzorca tekstu,Drugi poziom,Trzeci poziom,Czwarty poziom,Pity poziom,Cracow Grid Workshop,November 5-6,2001,Concepts for implementing adaptive finite element codes for grid computing,Krzysztof Bana,Joanna Paek,Cracow University of Technology,Outline,Motivation,FEM code as grid application,Current project,Future plans,Grid environment from application developer perspective,Open environment(coupling with external modules,standardization of interfaces),High performance communication libraries,Simpler code development,Cooperation with other groups,Broad user base,State of the art for the FEM,Complex problems(nonlinear,coupled,multi-scale,multi-physics),Complex codes(adaptive meshes,multi-level solvers,parallel and distributed execution),Steep learning curves for users,Unmanageable software for developers,Preprocessing,geometrical modeling,mesh generation,Postprocessing,GUI,interactive visualization,collaboration and steering,ODE integration,field discretization,adaptive mesh services,linear solver,Computational Module,Example finite element PSE,Current project-existing software,Adaptive FE codes in Fortran 77,Fortran 90,C,Areas of application:acoustics,elasticity,compressible fluid flow,multi-phase flow,electro-magnetism,hp-,adaptivity,Multi-level solvers,Parallel versions for PVM,DSM and MPI,Current project-application areas,Scattering of acoustic and,electro-magnetic waves,Current project-application areas,Subsurface flow simulation,(discontinuous approximation,multi-level solvers),Solver/preconditioner,Number of mesh levels,2,3,4,5,GMRES/single-level block ILU,9,15,30,59,GMRES/multi-level block ILU,7,8,9,9,Table1.Number of linear solver iterations to reach convergence,Current project-application areas,Compressible fluid flow,Current project,Modularization,Standardization of interfaces,Testing communication mechanisms,Coupling with visualization software,FE code modules,Assumptions:,code is built from small specialized modules,modules form separate libraries,modules have their own data structure,interfaces are designed for F90,C and C+,modules may define their own data distribution,modules are glued together by problem dependent code,FE code modules,Adaptive mesh procedures:,Read_mesh_data(mesh_id,read_type),Create_node(mesh_id,parameters,&node_id),Divide_element(mesh_id,element_id,element_sons_ids),Get_element_father(mesh_id,element_id,&father_id),Get_face_edges(mesh_id,face_id,face_edges_ids),Get_element_neighbors(mesh_id,element_id,neighbors_ids),.,FE code modules,Field discretization procedures:,Get_face_dofs(field_id,face_id,dofs),L2_project_dofs_from_element_to_element(,field_id,element_from_id,element_to_id),Get_solution_at_point(field_id,point_coordinates,solution),Set_uniform_degree_p(field_id),Write_element_solution(field_id,element_id,solution_dofs),.,FE code modules,Linear equations solver procedures:,Set_preconditioner_options(solver_id,preconditioner_type,preconditioner_parameters),Assemble_element_stiffness_matrix(solver_id,assembly_type,block_sizes,block_positions,stiffness matrices,load_vectors),Solve_system(solver_id),Store_face_solution(solver_id,face_id,dofs),Free_solver_memory(solver_id),.,Why adaptive FE code can be attractive as grid application?,Powerful tool for scientific and engineering analysis,Complex,multi-component code,Large amounts of data produced and exchanged among modules,Adaptive meshes require adaptive resources,Future plans,Sky is the limit.,Open,flexible,extensible FE software,Large-scale distributed computing,Integrated problem solving environment,
展开阅读全文