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DesignTool code has evolved into a com- (four-sided) cells to divide the Innovation Research (SBIR) mercial product known as flow field into discrete pieces g nder a Small Business contract with Lewis RAMPANT which is available instead of the six-sided cells TM, Research Center, Fluent Inc., on an annual lease basis. used in more traditional CFD Lebanon, New Hampshire Dr. Smith started work on codes. This approach provides developed a CFD (Computa- the SBIR project in 1987 with greater flexibility than the struc- tional Fluid Dynamics) software the goal of producing a CFD tured grid approach because it package for computing the flow code that was flexible, fast does not impose a fixed order around very complex shapes, and easy to use. To get flexi- on the layout of computational such as aircraft contours. bility, he used an innovative cells. RAMPANT also offers Developed by Fluent's unstructured grid approach. reduced cost of using CFD Dr. Wayne A. Smith, the CFD RAMPANT uses tetrahedral through a multigrid technique for getting flow solutions in minimal computer time. RAMPANT, says Dr. Smith, "is well suited for any problem that involves fluid flow and ASOFTWAREPACKAGE heat transfer around or inside complex geometries." The code's versatility was demon- FORFLOWCOMPUTA- strated in 1992 when it was employed to compute the flow TIONOFFERSABROAD of air around a Nordic ski jumper. Many of the jumpers in a competition had switched RANGEOFINDUSTRIAL to a new jumping technique called "V-style", a term that APPLICATIONS describes the shape the skis form while flying through the air with the ski tips spread far apart. Fluent made a compari- son of the flow over a V-style jumper (upper left) and a traditional jumper with parallel skis (lowerleft). RAMPANT's results showed that the longer distances V-style jumpers were getting was due to differences in aerodynamics caused by the change in ski positions. Transportation trucks, motorcycles, underhood and passenger compartment flows, and the flow through various engine components. At left is a RAMPANT computa- tion of the vortices (air whirl- pools) shed behind a moving auto of simple shape. In the turbomachinery industry, RAMPANT can predict the flow through axial and centrifu- gal turbines, inlet and exhaust ducts, and auxiliary cooling passages. The image below left shows the pressure contours on the surface of an axial flow compressor that was tested at Lewis Research Center. • TM RAMPANT is a trademark of Fluent Inc. RAMPANT, Smith adds, edge flaps. Knowledge of the "is especially applicable to characteristics of this flow is fluid flow problems in the essential to designing wings aerospace, automotive and with greater lift, which allow turbomachinery industries." lower (hence safer) speeds An example of an aerospace for aircraft landings and take- application that is easily offs. RAMPANT is able to handled by RAMPANT but predict accurately the maximum would be difficult to compute lift produced by airfoils with under the traditional structured multiple flaps. grid approach is prediction of In the automotive industry, the flow over an airfoil with RAMPANT can compute the leading edge and trailing external aerodynamics of cars, I Transportation