How to Define the CAD Geometry for a Turbo Inlet Duct

When you design high per­for­mance engines in the field of motors sports, you can find a variety of complex duct geome­tries, air intake man­i­folds and other weird-shaped com­po­nents. In order to increase the horse power of the engine, you can try to find the optimal shape of these geome­tries. For the advanced design of e.g. high flow turbo inlet ducts, a flexible and variable CAD geometry can dras­ti­cally speed up the overall process. With a set of design vari­ables, auto­mated opti­miza­tion strate­gies are able to change the geometry shape such that your objec­tives are min­i­mized or met (pressure losses, uni­for­mity, targeted flow char­ac­ter­is­tics etc.). At the same time, it is impor­tant not to violate the given space constraints. 

Geometry Setup for the Turbo Inlet Duct

For this article, we have created a simple demo model in CAESES® that shows the basic steps to set up the variable geometry. You first start with a path curve which in our model is a simple bspline curve. The control vertices of the curve can be con­trolled by design vari­ables. These vari­ables are changed manually by the user, or they are changed fully-auto­mated by para­me­ter study strate­gies or opti­miza­tion algo­rithms.

Besides a variable path curve, the shape of the duct shall also be variable while sweeping along the path: For instance, the shape changes from a circular shape to an ellipse shape at certain regions that can be defined. A function graph controls where to smoothly intro­duce the ellipse shape. Typ­i­cally, this is a feature that helps to improve the flow in highly curved regions. Below you can find some ani­ma­tions that illus­trate this behavior. 

Vari­a­tion of the Model

Once your geometry is ready, it can be con­nected to a sim­u­la­tion software (typ­i­cally CFD), to receive the relevant flow quan­ti­ties that actually shape your design. The gen­er­ated variants can be assessed in the design viewer of CAESES®:

In order to give you a better idea of the possible changes, take a look at the fol­low­ing animations:

Video

Finally, check out this short video which gives you an idea of how it looks when playing with this model in CAESES®:

More Infor­ma­tion

You want to learn more about CAESES® for auto­mo­tive appli­ca­tions? Then check out the product pages for more details.