For Ed Williams, simulation software is so fundamental to design that his conviction inspired a company, a computational fluid dynamics (CFD) solution, and the software's name -- CFdesign. Williams says he co-founded Blue Ridge Numerics Inc., Charlottesville, Va., to demonstrate why CFD analysis software should be used by product designers instead of off-line specialists. "The initial challenge for CFdesign was ease of use," says Williams, president. "We wanted to offer an alternative to conventional CFD software and counter its reputation for being difficult to master, time-consuming, and prohibitively expensive. Just hearing the words 'computational fluid dynamics' is usually enough to send shudders down the spines of most product-development engineers. The mention of CFD still tends to conjure up images of stern-looking men in white lab coats conducting experiments in NASA test cells." Version 5.0 facilitates the simulation of fluid flow and heat transfer within or around products -- cars, electronics devices, medical equipment, valves, or HVAC systems. Because of CFD's formidable reputation, however, only 6% of product engineers use it, says Williams. "The complexity [of conventional solutions] tends to discourage its use, and engineers soon forget how to use the tool." Williams says the new release can be integrated closely with leading CAD systems, enabling the user -- for the first time -- to incorporate fluid flow simulation into the design process. "It eliminates the need to perform actual physical prototype testing. As assemblies of parts are being designed, engineers can perform simulations directly on the geometry created in their CAD systems." Engineers quickly can perform multiple design changes -- all the "what-if" iterations needed to achieve the best possible design. Williams says that in the past, multiple "what-if" scenarios were seldom undertaken because of the time required to create another model on which to conduct the analysis. CFdesign's ease of use gives the non-specialist easy entry to the simulation solution, he adds. With conventional solutions, each change to the model required a new model be built with geometry import and clean-up, mesh generation, and application of boundary conditions. Start-to-finish analysis times were generally measured in terms of weeks or months of efforts, Williams says. "Discouraged, many design engineers turned to physical testing as a substitute. Unfortunately that only produces 'go/no-go' answers instead of the analytical insight the software approach can provide," Williams emphasizes. One customer, Rocket Development Corp., Los Alamitos, Calif., uses the software to validate rocket fuel injection systems prior to prototype testing. The simulation quickly identifies problems that could be dangerous during prototype testing.