Distributor Success with Sculptor

Optimal Solutions Software, LLC, is proud of its worldwide distributors and plans to highlight in its quarterly Sculptor e-Newsletter an outstanding Distributor for that quarter who has successfully sold the Sculptor product, utilized Sculptor to create optimal designs for its customer base and proactively marketed and spread the Sculptor name in the marketplace.

Located in Nantes, France, Sirehna signed its Distribution Agreement with Optimal Solutions on September 8, 2006, and has been successfully distributing Sculptor throughout France and Belgium, as well as speaking at conferences and trade shows about the technology and its attributes, ever since.

At the First International Conference on Multidisciplinary Design Optimisation and Applications (ASMDO) held in Besancon, France, from April 17-20, 2007, J.J. Maisonneuve, F. Pecot, and A. Pages from Sirehna jointly presented a paper entitled,

Comparison of Two Approaches for the Direct Optimisation of a Car Engine Intake Port.

Two optimization chains based on two alternative methods for the shape parametric deformation were compared by the Sirehna team:

  • Dassault Systémes' CAD-based deformation (Catia v5)
  • Optimal Solutions Software grid-morphing (Sculptor)

The work was performed within the Multidisciplinary Optimization project (OMD) Project, an initiative bringing together public laboratories and companies around the optimization of complex systems. This project is supported by the participants and the French "Agence Nationale de la Recherche" (National Agency of French Research) and the National Network of Software Technologies (ANR/RNTL). The test case and associated data were provided by Renault.

In the parametric grid-based optimization scheme:

  • Sculptor was utilized as the grid morphing tool;
  • Fluent, the CFD calculation method;
  • # post-processing, Fieldview and Matlab;
  • multi-objective optimisation environment performed by modeFRONTIER;

Results showed that there was "valuable design information provided" by the Sculptor team, as well as the Sculptor approach being "more robust in terms of ability to tolerate deformations...."

Remarks and Conclusions from the Sirehna team when comparing the two methods:

Shape Modification Based on CAD Parameters

  • requires strong modeling effort
  • leads to some limitations in terms of feasibility of the geometry (to compensate for this, have a preliminary analysis of the CAD generation robustness)
  • necessary to have optimisation environments and algorithms compatible with this lack of robustness
  • requires (for CFD application) to automatically create a mesh adapted to each shape (great difficulty for complex geometries)
  • expensive in grid-modeling time
  • modification of grid type and size — redefinition of the grid process
  • if the solutions are close to the unfeasible domain ¡V Pareto front can be affected
  • it is necessary to detect this to understand the behavior, and if necessary, to modify the model

Approach Based on Grid Deformations

  • no auto-adaptive mesh generation
  • deformations can exactly be applied at the desired locations
  • deformations remain valid whatever the grid used
  • deformation modeling time remains small
  • few restrictions in terms of parameter variations
  • some restrictions concerning the mesh quality can exist (use grid-quality criteria)
  • in practice, this approach is more robust — facilitates the optimization
  • some deformation can be difficult to model (large and combined variations)
  • another shortcoming: optimisation result is a mesh

Best results for both objectives:

  • mass flow rate +3.7% (variant A)
  • tumble +18.7% (variant C)
  • Valuable design information provided
  • more robust in terms of ability to tolerate deformations, even if some issues may occur