Commentary - Elements of Analysis, July 2006

By Jim Spann, Blue Ridge Numerics

It’s been called “CFD Lite” and some have said it is like giving guns to children.

The real name is Upfront CFD, and the only danger might be that all the rhetoric prevents design engineers from taking advantage of an opportunity to speed product development and improve quality without leaving their familiar MCAD environment.

Upfront CFD is not a subset of traditional computational fluid dynamics,  but a new category that is being defined by the marketplace. It refers to flow and thermal simulation integrated within an MCAD environment and used during early-stage product development. Upfront CFD customers report an average 65 percent reduction in project expenses. They are reclaiming as much as 70 percent of their project schedule—time that used to be set aside for basic design validation—to increase engineering quality and innovation.

The “CFD Lite” tag that is still perpetuated in some circles comes from watered-down teaser products designed to lure users into traditional full-scale CFD software. The “giving guns to children” business came from vendors who thought design engineers couldn’t assume CFD tasks.

True, Upfront CFD is anything but “lite.” An Upfront CFD package designed from the outset for design engineers provides the full spectrum of fluid-flow and heat-transfer analysis capabilities—it just does it in a very different way from traditional CFD offerings. Upfront CFD software should be tightly integrated with all major MCAD packages, and simple enough so that it can be used infrequently without any relearning curve. In many organizations, Upfront CFD complements traditional CFD.

The Upfront CFD process typically goes like this: A design engineer builds a simple, functional MCAD model, or uses an existing one, and conducts a first-pass simulation. Based on what is learned, more realistic geometric detail, material properties and operating conditions are added to create a set of candidate design variations for simulation. Design reviews are conducted with interactive 3D simulation results instead of bench test data. Ideas are tested, changes are made, and eventually a production-ready MCAD model is submitted for final validation at the lab.

Typical users of Upfront CFD know a lot about the products they engineer,  and are comfortable working with MCAD, but solving fluid-flow and heat-transfer problems might be only one of a dozen areas for which they are responsible. They typically have well-defined product performance questions and only a few days to get reliable answers. They don’t have time to be experts in fluid and thermal dynamics, much less subjects such as finite volume, finite elements, model meshing, and solver selection. The software has to provide that kind of expertise for them.

A key tenet of Upfront CFD is tight MCAD integration. All geometry changes are made in the familiar MCAD system; the Upfront CFD system instantaneously recognizes and adapts to design changes without loss of product data. There is no need to import or translate a product design into the analysis environment, and all associated design properties are automatically carried over from MCAD into the upfront CFD software.

Just as we have shed names and stereotypes that misrepresent people,  places, and things, so should we rethink our notions of relationships between CAD and analysis based on new technologies and processes.

Do we consider a hybrid car “lite” because savvy engineers have found a way to provide greater fuel efficiency for those who want and need it? True Upfront CFD has done something similar: provided new software with built-in intelligence that makes powerful CFD capabilities accessible to the everyday design engineer.

Far from giving a gun to a child, Upfront CFD gives a logically designed toolkit to a professional with specific skills and the need to save time and money in the design process.

Jim Spann is vice president of marketing for Blue Ridge Numerics, Inc. (Charlottesville, VA), maker of CFdesign software. Send your comments about this commentary through Send your comments about this article through e-mail by clicking here. Please reference “Truth About CFD, July 2006” in your message.