First-Pass CFD Analyses: Part 1

By Pamela J. Waterman

This pressure regulator model is part of amulti-component digital prototype where Blue Ridge Numeric’s CFdesign was used to evaluate system performance during the early engineering phase of a firefighting pumper truck. The tank, pump, pressure regulator, flow control valve, and nozzle were included in the simulation, illustrating a wide range of applications ideally suited forfirst-pass CFD. Image courtesy Blue Ridge Numerics.

Turbulent water, cooling air, viscous oil, liquid plastic — regardless of its specific type, the impact of fluid flow on successful part or assembly performance can range from modest to critical. Many mechanical engineers come to this analysis task with minimal experience, yet need to make quick decisions about heading down the “best” design path before spending a large portion of the design cycle on refinements.

How are today’s engineers honing in on these first-pass, upfront evaluations? They’re doing it with computational fluid dynamics (CFD) software that pays crisp attention to their operational needs.

The driving factor seems to be ease-of-use, defined by a short learning curve, intuitive user operations, and clear tutorial examples. Flexibility in changing parameters for quick, multiple what-if runs ranks next, and third is some level of automation. Lastly, good support through phone or online help is crucial; the latter particularly so because many users fall into the occasional-use category.

Products that often come to mind for upfront CFD include STAR-Works from CD-adapco, EFD.Pro from Flomerics, CFdesign from Blue Ridge Numerics, COSMOSFlow from SolidWorks, and FloWizard from ANSYS/Fluent. However, many users find equal success with such classics as CFX from ANSYS, 3D-Fluid from Cranes Software, PowerFLOW from Exa, Flow3D from Flow Science, Algor from Algor, NX Flow from Siemens PLM, COMSOL from COMSOL, PHOENICS from Concentration Heat and Momentum Ltd (CHAM), and PORFLOW from ACRi — the list goes on (for an extensive CFD listing and directory click