A quick look at mimmo

Introduction

mimmo is an open source C++ library for manipulation and morphing of surface and volume meshes. The aim of the project is to provide users with a ready-to-use tool for build his own application code embedding objects of mimmo library.
The package is organized as a library of blocks that can be linked and organized in an execution chain as in a block diagram workflow.
The library provides a large set of blocks aimed to perform basic or advanced morphing of surface or volume meshes. An user can be develop his own blocks by easily coding new customized classes.

Features and tools

The core of mimmo are the objects that allow to manage surface and volume meshes. This elements are hidden to the user and integrated in the base classes of the library. The majority of the utilities are powered by the grid manager utilities of bitpit library. The main features of mimmo are:

• Input/Output of various surface mesh formats:
  • STL, VTU
• Input/Output of three-dimensional curves and point cloud:
  • VTU, OpenFOAM points format
• Input/Output of third party surface and volume mesh formats:
  • CGNS, OpenFOAM volume meshes
  • NAS nastran models as surface meshes
• Geometry parametrization and deformation:
  • Free Form Deformation (FFD) based on lattice parametrization of volume with different base shapes (cube, sphere, cylinder)
  • space parametrization and geometry deformation based on Radial Basis Function (RBF)
• Basic deformations:
  • rigid rotation, rigid translation, scaling, twisting, polynomial based bending
• Basic tools for mesh selection and field extraction and merging :
  • selection of sub-meshes by elementary shapes, by proximity, by PID and scalar and vector field extraction and overlapping
• Basic tools for mesh managing, deformation, check and repair :
  • volume mesh check, multiple bodies manager, stitching, clipping, triangulating, refinement, smoothing, penetration control, bounded deformation
• Propagation of boundary fields in volume meshes (e.g. propagation of the displacements of the boundaries for a mesh morphing procedure):
  • laplacian based propagation

Execution Chain

By the use of mimmo library the objects instantiated in a code can be insert in a container, the execution chain. This container allows the automatic ordering of the objects and the managing of their relationship. This permits a straighforward setup and execution of the block diagram flow.

References

A. Cominetti. Open-source Shape Optimization: an application to Bulbous Bow. Master of Science Thesis in Mechanical Engineering. DIME, University of Genova, Italy(2017). pdf

E. Lombardi. An example of Reduced Order Models at work: aerodynamic shape optimization through a coupled CFD-POD approach. Workshop: Industry and mathematics. IHP, Paris, France (2016).

M. Bergmann, A. Ferrero, A. Iollo, A. Scardigli. An approach to perform shape optimisation by means of hybrid ROM-CFD simulations. NMPDEs-ME3 Conference Recent Developments in Numerical Methods for Model Reduction. IHP, Paris, France (2016).

F. Salmoiraghi, G. Rozza, A. Scardigli, H. Telib. Reduced Order Methods for Automotive and Nautical Applications. XIII Biannual Congress of SIMAI. Milano, Italy (2016).

A. Scardigli, R. Arpa, H. Telib. Large-Scale Aerodynamic Shape Optimization using POD-based reduced-order modeling. Mini-workshop in the framework of the INDAM-GNCS project: Computational Reduction Strategies for CFD and Fluid-Structure Interactions Problems. Trieste, Italy (2015).

A. Scardigli, R. Arpa, H. Telib. POD-based reduced-order modelling for large-scale aerodynamic shape optimization. Reduced Basis Summer School. Allensback-Hegne, Germany (2015).

A. Scardigli, H. Telib. Shape Optimization of Large-Scale Aerodynamic Problems using Reduced Order Modelling. Seminar @ University of Konstanz. Konstanz, Germany (2015).

A. Scardigli, R. Arpa, A. Chiarini, H. Telib. Enabling of Large Scale Aerodynamic Shape Optimization through POD-based Reduced-Order Modelling and Free Form Deformation. EUROGEN 2015. Glasgow, Scotland (2015).

H. Telib, R. Arpa, A. Scardigli, E. Dini, A. Torluccio. A framework for aerodynamic shpae optimization using free form deformation and domain decomposition. Aerovehicles 1 Conference. Bordeaux, France (2014).

A. Scardigli. POD Reduced-Order Modelling Applied to Aerodynamic Shape Optimization. YS3 INDAM Young Scientists Seminars Series on Reduced Order Modelling. Trieste, Italy (2014).