Blog

Published November 1, 2016

Time-Savers in CONVERGE Studio

Author:
Sarang Vijayraghavan

Senior Research Engineer

Local coordinates

Modern fuel-injected engines are geometrically complex, and such complexity makes every aspect of computational analysis more challenging. You might have passed off CAD duty to a colleague, and you can avoid discretizing the volume with CONVERGE’s automatic meshing and cut-cell capabilities, but there’s still the matter of injector configuration and setup. CONVERGE allows you to rapidly set up a local coordinate system (LCS) for each injector, avoiding the tedium and bookkeeping of manual coordinate transformations.

Consider the port fuel injected engine intake pictured here. The injectors (green) are not aligned with the global x, y, or z axes, nor are they aligned with each other. We will set up an LCS for each injector.

converge-port-fuel-injected-engine

First, we use CONVERGE to calculate the spray axis by measuring the normal of the injector face and saving it to the Coordinate Cache. We also measure and save the centroid of the injector face. Then we go to Create > Coordinates and copy the cached normal vector, saving it as a new LCS.

converge-spray-axis-1
converge-spray-axis-2

Next we open the nozzle configuration editor and change the coordinate system from Global to your new LCS. The spray plume is now oriented along one of the axes of the LCS, and any edits or adjustments are clean and simple.

converge-spray-plume

Surface refinement

CONVERGE has no trouble with surfaces that are discretized with very high aspect ratio triangles, but some other computational packages aren’t so forgiving. CONVERGE Studio provides a quick and easy tool to coarsen or refine a surface discretization, providing a triangulation that is nearly isotropic.

This process is as simple as selecting the triangles you want to replace and then going to Geometry > Create > Triangle. Select the Refine Triangles option and choose your target edge length. With but a moment’s work, you can create a nearly isotropic surface triangulation suitable for export to the most demanding third party software.

converge-surface-refinement-2
converge-surface-refinement-1