The worldwide 1997 Fluent Users' Group Meetings featured outstanding presentations by users of FLUENT, FLUENT/UNS, FIDAP, RAMPANT, NEKTON, and POLYFLOW and attendance was high at meetings in the USA, UK, Korea, Japan, Sweden, Germany, and France. Feedback from the user community made the meetings extremely valuable to Fluent, and important information on product directions was received by the attendees. Highlights of selected presentations at the USA and UK meetings held in June are noted below.

The 1997 meetings brought FIDAP users together with Fluent software suite users in a first-ever information exchange.

Design of Rockets and Ramjets

Rocket engine designers at GenCorp Aerojet are using Fluent software to study combustion performance, combustion stability, thermal loads, and nozzle performance, and this presentation included a summary of several interesting CFD studies conducted to date. Results included FLUENT predictions characterizing secondary flows (longitudinal vortices) in gas generator piping, performance of round-to-square converging-diverging nozzles, plume flows of underexpanded jets, and ramjet/scramjet combustion (see figure 1.). Aerojet scientists also confirmed through transient simulations and comparisons with exact analytical solutions that FLUENT can correctly predict the shape of the first tangential acoustic mode in a cylinder. The presentation showed results from FLUENT/UNS that were used to design new, innovative fuel injector elements for H₂ - O₂ combustion.

Figure 1. Effects of fuel injection velocity on temperature contours in a ramjet combustor. Courtesy of GenCorp Aerojet.

CFD for Turbine Film Cooling

Professor James Leylek at Clemson University presented results of his research efforts using FLUENT/UNS to study film cooling. Film cooling is routinely used in gas turbine engines to cool engine components in the hot-gas flowpath, and involves design tradeoffs between structural integrity and engine efficiency. Today's design practice employs experimental data and field experience, which may not be adequate when significant changes are made to film-cooled parts. In order to establish the possible use of CFD for film-cooling design, researchers at Clemson are trying to improve the understanding of the turbulent mixing and vortex generation that occur as the cooling film interacts with the hot gas stream. Their initial results for the mixing process in flow over a flat plate were presented at the Fluent meeting, as well as at the 1996 and 1997 International Gas Turbine Institute conferences.

Figure 2. FLUENT/UNS closely matched the measured film effectiveness in this benchmark study of film cooling. Courtesy of Clemson University.

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