A N S Y S Advantage Volumen 1 Issue 2 2007


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A N S Y S Advantage Volumen 1 Issue 2 2007

  2. 2. EDITOR’S NOTEThe Big QuestionWith engineering simulation becoming so widespread, the big questionnow for manufacturers is not if to use the technology but how. Andtheir answers will determine who gains the competitive edge. Companies are investing in CAE technology, the competitive edge isn’t necessarily engineering simulation at unprece- determined by which companies use simulation — most dented levels. According to the manufacturers now implement it in one way or another — latest statistics from market but rather how they uniquely apply the technology in their research and technology assess- organizations and integrate it into their product develop- ment firm Daratech, sales revenue ment processes. for computer-aided engineering To fully leverage a solution, many successful firms have (CAE) software and services grew initiatives for performing more upfront simulation to refine from $2.31 billion in 2005 to more designs early instead of trying to hurriedly fix problems than $2.43 billion in 2006. Daratech near the end of development. In most cases, this means forecasts a compound annual deploying appropriate tools beyond the ranks of dedicated growth rate of 13 percent through analysts to more rank-and-file engineers and designers for2010, when figures are expected to top $3.7 billion. routine use throughout development.Driving this expansion is the tremendous need for There is no cookie-cutter way to best implement suchcompanies to shorten time to market, lower costs, improve an approach. Rather, companies have found that they mustperformance and develop steady streams of knock-out, carefully evaluate their existing processes, skill sets,innovative products. With survival on the line in many organizational structures, product strategies and businesscases, manufacturers use simulation as a proven way of priorities to leverage simulation most effectively. Scheduling,addressing these issues. funding and performance reviews generally are adjusted to According to Daratech statistics, the number-one player allow for training; the approach also gives engineersin CAE is ANSYS, Inc. So a substantial portion of the broad and designers the time they need to perform analysis,range of simulation applications worldwide is based on the what-if simulations and optimizations in the early stages ofcompany’s suite of solutions. The breadth of applications is development rather than the usual rush to finalize computer-evidenced by the articles in this current issue of ANSYS aided design (CAD) models.Advantage on simulation projects involving the design of These and other necessary organizational changesproducts ranging from trucks and turbojet engines to con- require a significant investment in time and effort, ofsumer goods and healthcare equipment. The content also course, but the level of commitment defines howdemonstrates the vast range of company sizes, from the companies uniquely leverage simulation; it also determinesone-man design firm Stein Design in the story “No-Hassle which firms will most likely lag behind while othersKitchen Appliance” to the $70 billion global consumer reap the greatest business value from Simulation Drivenproduct giant Procter & Gamble Company in the article “The Product Development. ■Democratization of Engineering Analysis.” As these and other successful simulation users know,gaining market advantage now takes more than justutilizing analysis tools. Because of the ubiquitous use of John Krouse, Editorial DirectorFor ANSYS, Inc. sales information, call 1.866.267.9724, or visit www.ansys.com.To subscribe to ANSYS Advantage, go to www.ansys.com/subscribe.Editorial Director Editors Editorial Advisor About the Cover About the BiomedicalJohn Krouse Marty Mundy Kelly Wall Racing yachts competed this Spotlight Fran Hensler summer in the America’s Cup The biomedical industry isProduction Manager Erik Ferguson Circulation ManagersChris Reeves Richard LaRoche Elaine Travers competition in which all the emerging as a strategic user Thierry Marchal Sharon Everts leading teams employed computer of engineering simulation.Art Director simulation to gain an edge. See One research team has foundSusan Wheeler Ad Sales Manager Designers page 3. Cover photograph ©ACM that improvements in cochlear Beth Mazurak Miller Creative Group 2007/Photo: Carlo Borlenghi. implants might be possible Simulation courtesy Christos using shape memory alloys.Email: ansys-advantage@ansys.com Pashias, Team Shosholoza. See page s4.ANSYS Advantage is published for ANSYS, Inc. customers, partners and others interested in the field of design and analysis applications.Neither ANSYS, Inc. nor the editorial director nor Miller Creative Group guarantees or warrants accuracy or completeness of the material contained in this publication.ANSYS, ANSYS Workbench, CFX, AUTODYN, FLUENT, DesignModeler, ANSYS Mechanical, DesignSpace, ANSYS Structural, TGrid, GAMBIT and any and all ANSYS, Inc.brand, product, service, and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries located in the United Statesor other countries. ICEM CFD is a trademark licensed by ANSYS, Inc. All other brand, product, service and feature names or trademarks are the property of theirrespective owners.2 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com© 2007 ANSYS, Inc. All rights reserved.
  3. 3. CONTENTS Contents Feature 3 SPORTS 3 The Simulation Race for America’s Cup Yacht designers used engineering simulation in a variety of applications to edge out the competition. Applications 7 MATERIALS/PARTNERSHIPS 7 Plying the Composite Trade ESAComp software overcomes challenges in designing with composites. 10 CONSUMER PRODUCTS Hair Today Product developers in the cosmetics industry can put simulation to use in performing hierarchical analyses of hair care product performance. 12 AUTOMOTIVE Heavy-Duty Lightweight An innovative aluminum design gives a truck-body manufacturer the 10 competitive edge in the worldwide construction industry. 14 POWER GENERATION Gassing Up with Coal A two-fluid multiphase model allows for more accurate simulation of coal gasification. 12 16 PROCESS EQUIPMENT Chopping Away at Solids CFD simulation provides a pump company with a virtual test facility. 14 20 CONSUMER PRODUCTS No-Hassle Kitchen Appliance Finite element analysis helps redesign a countertop water filter. 22 AEROSPACE Overcoming Big Challenges for Small Turbojet Engines 16 Engineers used FEA to develop an impeller for a microjet turbine engine for unmanned drone aircraft. 24 POWER GENERATION Keeping It Cool Modeling fluid flow and heat transfer throughout a nuclear fuel assembly helps prevent reactor burnout. 20 26 PROCESS EQUIPMENT The Greening of Gas Burner Design Simulation assists in developing efficient and environmentally friendly recuperative burners used in heat-treating applications.22 (Continued on next page) 24 26 www.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 1
  4. 4. CONTENTS 19Departments 19 TRENDS & PRACTICES Managing Engineering Knowledge Web-based solution is aimed at hosting and integrating simulation data, processes and tools for more effective Simulation Driven Product Development. 28 THOUGHT LEADERS The Democratization of Engineering Analysis 28 To compete successfully in today’s business climate, Procter & Gamble makes analysis tools available to rank-and-file engineers as well as to analysts and advanced simulation experts. 31 31 ANALYSIS TOOLS Rotordynamic Capabilities in ANSYS Mechanical Useful features are available to study vibration behavior in rotating parts. 34 TIPS & TRICKS Submodeling in ANSYS Workbench To obtain accurate stress in a local region, submodeling separates local analysis from the global model. 34Spotlight on Engineering Simulation in theBiomedical Industry s2s2 Making Life Longer and Better s4 The biomedical industry is emerging as a strategic user of engineering simulation.s4 Turning Up the Volume The use of shape memory alloys offers the promise of better functioning in cochlear implants.s6 Hip to Simulation Evaluation of designs for a hip replacement prosthesis overcomes physical and scientific limitations.s7 Walking Pain Free s6 New insoles designed with the ANSYS mechanical suite relieve pain from foot disease.s8 Engineering Solutions for Infection Control s7 Simulation assists in designing a hospital ward to reduce the airborne transmission of disease.s10 Standing Up Right ANSYS Multiphysics sheds light on the wonders of the s8 human spine and how to fix it.s12 Designing with Heart s10 CFD-based design optimization for a pediatric implant can shave years off the development cycle. s12s14 Going with the Flow Functional biomedical imaging through CFD provides a new way of looking at pathological lungs.s15 Battle of the Bulge Rapid prototyping results in a new surgical tool to treat back pain. s14 s152 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  5. 5. SPORTS Emirates Team New Zealand used CFD to predict the effect of design alternatives on yacht performance.The Simulation Racefor America’s CupYacht designers used engineering simulation in a varietyof applications to edge out the competition. The America’s Cup is the most famous sailing regatta in team would challenge Alinghi for the trophy in 2007, anthe world and also the oldest active trophy in international ambitious schedule of regattas was held, commencing insport. The trophy, originally known as the Royal Yacht 2004 and culminating with the Louis Vuitton Cup this pastSquadron Cup, was first awarded in 1851 when the New spring. The America’s Cup match series was held in lateYork Yacht Club schooner America defeated 15 Royal Yacht June and early July, with Alinghi the winner in the closestSquadron challengers in a race around the Isle of Wight in Cup in recent history.England. In honor of America’s victory in the first competi- The racing syndicates that compete for the cuption, and the subsequent dominance of American boats for are composed of the best sailors, designers, sailmakers,over a century, the trophy officially became known as the nautical engineers and boat builders in the world. The topAmerica’s Cup. teams expend more than 150,000 labor hours to optimize Despite its name, it is truly an international competition. the designs of their boats. All of the leading teams employIn 2003, the Swiss challenger Alinghi defeated Team New computer simulation to determine the power generated byZealand to win sailing’s grand prize; Alinghi successfully the sails, the drag produced by the boat’s hull and the airdefended this summer at the 32nd America’s Cup in resistance of the deck. Four of the top teams, includingValencia, Spain. The boat sizes and designs have varied BMW ORACLE Racing from the United States, Souththrough the years, ranging from the 130-foot J-class yachts Africa’s Team Shosholoza, Emirates Team New Zealandof the 1930s to a 60-foot catamaran in 1988. Since 1992 (ETNZ) and defending champion Alinghi from Switzerland,though, the teams have sailed an International America’s use computational fluid dynamics (CFD) software fromCup Class (IACC) sloop, a monohull boat that has an ANSYS, Inc. to predict the effect of design alternatives onaverage length of about 75 feet. To determine which yacht performance down to the smallest details.www.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 3
  6. 6. SPORTS CFD simulates the wind flowing over the deck and cockpit of the Alinghi boat. Note the vortex that formed in the bow where the wind wraps around on the deck. The two most critical aspects of yacht performance are position of the winches, and they also looked at the shapethe sail aerodynamics and the hydrodynamics of the hull of underwater components, such as the ballast bulb.and appendages. Picture this analogy: A racing yacht is like “Our new simulation methods make it possible to modela plane floating on its side with one wing sticking up in the the most complex problems down to the finest details in aair and the other down into the water. The art of yacht day or two,” said Ian Burns, design team coordinator fordesign is to extract drive force because the two fluids (air BMW ORACLE Racing. “We now can determine the effectand water) have different speeds and directions. The curva- of the smallest changes, such as the shape of the deck orture of the sails generates lift in a manner similar to an small hardware components on the mast. Some of theseairplane wing, while the keel of the boat generates lift in the changes can have a significant impact on performance andopposite direction — like the opposite wing of the airplane are helping us make significant performance improvements.— to prevent the boat from moving sideways. The keel can We have analyzed and improved nearly every detail of thebe proportionately much smaller than the sails because boat with ANSYS CFX software.”it operates in a fluid 800 times denser than air. As inaircraft design, improving performance of a racing yacht isbasically a question of maximizing lift and minimizing drag.Small changes in geometry often make the differencebetween a competitive boat and an also-ran.BMW ORACLE Racing: It’s In the Details In the 2003 competition, BMW ORACLE Racing used apublic-domain CFD code to simulate the performance oftheir boat. However, they found that meshing and solutiontimes were so long that they were forced to simplify theirmodels to the extent that they could not distinguishbetween small design changes. For the 2007 race, the teamused ANSYS CFX software. BMW ORACLE Racing ranmodels with 10 to 15 million cells on large computerclusters that can resolve the performance impact of thesmallest design changes. The team’s designers simulatedthe performance of large numbers of different sail shapesand trims to understand performance under a variety ofconditions. They evaluated the aerodynamic effects of the An upwind aerodynamic simulation of the Team Shosholoza yacht clearly shows the tipdeck, such as the shape of edges and corners and the vortices. Induced drag reduction is important for sails operating near their maximum lift.4 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  7. 7. SPORTSTeam Shosholoza: Big Things from Small Packages and site-specific changes, such as optimizing the bulb Team Shosholoza, South Africa’s first America’s Cup design for the expected conditions off Valencia.entrant, was one of the smaller teams in this year’s compe- “We developed a genetic algorithm that works bytition. Unlike some of the larger teams, Shosholoza has only defining the geometry of the bulb with control points whoseone boat, so it can’t rely on running two boats against each coordinates and weighting are considered to be genes,”other to evaluate design changes. Therefore, CFD simula- said Nick Holroyd, designer for ETNZ. “Then the populationtion is critical to the team, which has built a 42-node cluster was seeded with a range of candidates, and mutationsthat places it near the top in terms of computing capabilities were introduced into each generation to adequately spreadamong the smaller entrants. Shosholoza used computer- the population across the design space. Each candidateaided design (CAD) tools to develop a parametric model of was simulated with ANSYS CFX software using the laminar-the boat and then read the model into the ANSYS ICEM to-turbulent transition model to provide a drag value.CFD Hexa meshing tool, which quickly generates a series This value is factored against the stability contribution ofof models by varying a key design variable over a defined the shape to provide a fitness score for the design. Werange. Shosholoza then solved the models with ANSYS developed a family of new bulb shapes with a betterCFX software, and designers used the results for force anddrag to predict the velocity. “To date, the area where we have made the greatestimprovements is in the shape of the sails,” said ChristosPashias, fluid dynamicist for Shosholoza. “We are trying toget as much power out of the sails as possible because thewinds in Valencia are so light. We set up a parametric modelto automatically generate sail models. This enabled us tohave a quick turnaround and study more shapes. Being anew team, initially we made improvements of between5 and 10 percent in driving force. A 1 percent improvementin driving force typically increases the speed of the boatby about 0.1 percent. We have tested boats with thenew designs and discovered that they actually do providethe performance improvements that ANSYS CFX predicts.Since we made those initial big gains, we have mademany other improvements that have provided smallergains, typically in the area of 1 percent, which is what mostteams are after. Testing already has shown that thesepredictions are accurate, so we trust them to makemore improvements.” Shosholoza also used FLUENT CFD software to betterunderstand the flow of water around the yacht. The rankingof candidate hull shapes by FLUENT software agreed wellwith experimental results.Emirates Team New Zealand: Location, Location, Location ETNZ has been focused on improving the ballast bulbat the bottom of the boat. At about 21 tons, this torpedo-shaped lead component makes up nearly 80 percent of theboat’s mass and provides the craft with the stability tobalance a very large sail area. Choosing a bulb shape with alower center of gravity increases the boat’s righting momentand enables the sail to provide a larger driving force. On theother hand, moving to a lower drag force wastes less of theavailable driving force and increases the speed of the yacht.In preparing for the 2003 race, the New Zealand designerswere able to lower the center of gravity substantially without Simulations were conducted under a wide variety of conditions to determine performance. Velocity magnitude contours around the hull and sails of theany increase in drag. With these major improvements under BMW ORACLE Racing boat are shown (windward above and leeward below)its belt, the team’s goal for 2007 was to make more subtle with plane cuts that are perpendicular to the boat track.www.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 5
  8. 8. SPORTSBMW ORACLE Racing has analyzed and improved nearly every detail of the boat, Team Shosholozaincluding the keel–ballast bulb juncture.drag/stability trade-off for the racing conditions expected at calibrated its results,” said Jim Bungener, CFD engineer forValencia. This approach made it possible to evaluate the Alinghi. “The main areas where we have made performancedesign space with much less time than would have been improvements have been in the winglets on the ballastrequired manually.” bulbs and the downwind sails or spinnakers. We also have made smaller gains in areas such as winch placements andAlinghi: Defending Its Honor pillar shapes. These improvements have significantly Winner and defending champion Alinghi used CFD to increased the speed of the boat. When considered as aevaluate every portion of the boat, including the sails, the whole, the results that we have achieved with CFD aided usunderwater portion of the hull and deck details. Alinghi considerably in defending the America’s Cup.” Bungenerdesigners spent more than a year evaluating CFD results also used ANSYS Structural software to identify the com-compared to wind tunnel testing and scientific papers. posite laminar structure that withstands the loads on the“We gained confidence in the ANSYS CFX software and hull while minimizing weight. Steady Wins the Race Computer simulation has played a crucial role in the boat design process for many of the top racing syndicates. With all entrants now using CFD to optimize the performance of their boats, different design groups have arrived at generally the same conclusions and made substantial performance improvements. As a result, the boats are closer together in terms of performance, making tiny improvements that much more important. The teams now are all creating finer and finer meshes using larger clusters of computers so they can evaluate the effects of smaller design changes on yacht performance. The America’s Cup is thus becoming a showcase, not only for the world’s fastest yachts but also for its most powerful simulation tools. ■ This article was written through contributions from Alinghi, BMW ORACLE Racing, Emirates Team New Zealand and Team Shosholoza.Alinghi simulation of typical downwind sail geometry illustrates the way air flowsover the sails. A large vortex is created behind the spinnaker, a billowing sail usedwhen the wind is behind the boat.6 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  9. 9. MATERIALS/PARTNERSHIPS Dialog boxes in the ESAComp ply specification tool enable users to readily enter various input data.Plying the Composite TradeCoupled with technology from ANSYS, Inc., ESAComp By Harri Katajisto Componeering Inc.software overcomes challenges in designing with composites, Helsinki, Finlandenabling engineers to evaluate part designs and better usethese versatile materials to their full advantage. Carbon-fiber reinforced plastics When designing with laminated Concerned about the inefficiencyand other composite materials are composites, engineers must take into and lack of consistency between theused in a wide range of applications account these and many other con- wide range of in-house codes used inbecause of their high strength- siderations in establishing important the aerospace industry, the Europeanto-weight ratios. High-performance design variables, including selection Space Agency (ESA) initiated a projectcomposites made of continuous fibers of material types, layer orientation in the early 1990s to standardize thebound with thermoset resins can be and thickness, number of layers, and analysis approach with a single soft-used in making extremely efficient stacking sequence. Compounding the ware platform combining various toolsstructures, and laminated composites difficulty, complete material property under a unified user interface. ESA,are well suited for lightweight parts data cannot always be found from the with headquarters in France andwith complex surface contours. supplier data sheets. consisting of 17 member states, is in Composites present some com- charge of shaping the developmentplex challenges in utilizing these Composite Analysis and Design of Europe’s space capability andmaterials to their best advantage, High-performance composites are ensuring that investment in space con-however. Material properties are used extensively in the aerospace tinues to deliver benefits to the citizensanisotropic — that is, they are direc- industry, where engineers rely on of Europe. By coordinating membertionally dependent on the orientation in-house tools developed specifically resources, the agency can undertakeof the reinforcing fibers. Differences in for composite analysis. These pro- programs and activities far beyond thethermal expansion of the matrix and grams require considerable resources scope of any single European country.reinforcing materials cause residual to develop and maintain, however. ESA also works closely with spacestresses, and asymmetric structures Engineers need extensive training to organizations outside Europe.especially can yield unexpected understand the specialized command- Development work for the com-responses to temperature variations. based interfaces and numerical posite project was conducted byMoreover, sandwich structures exhibit outputs. In addition, users often have Helsinki University of Technology incomplex behavior because of large to transfer data manually between Finland, and the first version ofdifferences in strength and stiffness multiple programs for modeling and ESAComp software was released inbetween layers. analyzing components. 1998. Development responsibility laterwww.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 7
  10. 10. MATERIALS/PARTNERSHIPS Layer charts indicate the effect of layer orientations on interlaminar shear stress distribution in a short beam test sample. can study constitutive relations and The software includes a material hygrothermal behavior of laminates, for database of fibers and matrix example, and compare laminate lay- materials, adhesives, sandwich core ups with respect to strength and other materials, and reinforced material design requirements. Input checks systems from commercial suppliers. help guarantee that analyses are not A ply specification tool in ESA-was transferred to the spin-off Finland- performed with inadequate data. Comp is particularly valuable in settingbased company Componeering Inc., Users can run preliminary design up the input data for various materialwhich now distributes and supports checks to ensure that columns do not configurations, such as a curedthe software. Although the software buckle, plates withstand applied loads fiber-matrix system or a honeycomboriginated in the aerospace industry, it without deflecting excessively, pres- core material. Since ply behavior ishas been developed as a general tool sure vessels carry specified internal typically between isotropic and fullyfor engineers in other applications pressures, joint configurations are anisotropic, the ply specification tooldesigning with high-performance com- efficient for load transfer, holes in utilizes material symmetry rules to helpposites, including automotive, marine, plates do not cause severe stress in defining the data. Ply data also canconstruction, machinery, rail trans- concentrations, and scatter in material be derived from fiber and matrix dataportation, sports and wind energy. properties does not cause unexpected with micromechanics analyses. The software has analysis and problems. The initial solution obtained With the laminate lay-up tool, lami-design capabilities for solid–sandwich gives a starting point and benchmark nates can be created and editedlaminates and micromechanical when going to finite element analysis efficiently. The user has a wide range ofanalyses. It further includes analysis (FEA) of the full structure, after which options for performing analyses as welltools for structural elements: plates, post-processing of the results helps as selecting and combining result data.stiffened panels, beams and columns, survey the numerous failure mech- For example, several laminates,and bonded and mechanical joints. anism possibilities. laminate orientations or failure criteriaESAComp focuses on the conceptualand preliminary design of compositestructures as well as detailed productevaluation using ANSYS Mechanicaland other analysis software. EngineersANSYS, Inc. software and ESAComp were instrumental in the design The esaplot viewing utility gives quick insight into the overall safety performance of the yachtof the 75-foot Wally-class racing yacht. design. For each composite element, a safety factor determined by the most critical layer of the section is given. Options provide detailed data on the laminate failure mode and the most criticalImage courtesy Johannes Schlieben, University of Applied Sciences of layer, with this information overlaid on each element. Here, for example, cs indicates core shearNorthwestern Switzerland. failure, and w(n) denotes wrinkling of the face sheet. The second option characterizes the most critical layer: the stacking number and the orientation.8 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  11. 11. MATERIALS/PARTNERSHIPS Analysis determined criticality of the interlaminar shear strength for the trailer tank structure during deceleration. Margin to safety is indicated with contours, and results of the failure analysis are overlaid on the elements.A liquid-hauling tank and associated structures of the truck were analyzed. The truck’stank was made of filament-wound composites and sandwich structures.can be selected for different types laminate definitions from an ESAComp driver; simulation tools were critical inof analyses. The results display FE export file. When the geometry optimizing the lay-ups and certifyingoptions include numeric tables, line is imported as surfaces, ANSYS the laminates of heavily loaded compo-and bar charts, failure envelopes, and Workbench automatically uses shell nents, such as the chain plates and thecontour plots. 181 elements. After elements have junction between the keel box floor and been updated to correspond to the the hull.Integration with Software from ANSYS, Inc. correct laminate definitions, the model Another application involved a ESAComp is fully integrated with is solved and post-processed. design project for a truck with a liquid-ANSYS Mechanical software. ESA- Integration of ESAComp post- hauling tank made of filament-woundComp FE export supports ANSYS processing with ANSYS has been composites and sandwich structures.pre-processing. Also, the program can realized with the versatile ANSYS Advanced contact features andbe launched from the ANSYS interface Parametric Design Language (APDL) automatic meshing capabilities in theto perform detailed stress analysis and and is used through two commands: ANSYS Workbench environment werepost-processing. ANSYS Mechanical esapost and esaplot. The most rele- used to transform the CAD geometry ofsoftware allows defining FE model vant data can be combined in a single the tank support structure to the FEinput files in text format using specific ANSYS contour plot showing safety model. ANSYS parametric modelingcommands, which is, in many cases, margins for the most critical failure features and interfacing capabilitiesthe best way to set up models; the mode, including layer failure, inter- with ESAComp were further used toESAComp FE export capability fits in laminar shear, or sandwich core shear optimize the design. Finally, ANSYSthis scheme. The ANSYS Workbench and wrinkling. Text labels on elements Mechanical software was used forplatform supports these text format provide additional information on validating the design against the cer-laminate definitions as well. For each the failure modes or critical layers. tification authority’s requirements.part in the model tree, the user can Through this procedure, the user Processing indicated how interlaminargive ANSYS commands through quickly identifies design-driving areas, shear (ILS) strength of the laminateANSYS Workbench command objects. since all relevant failure modes are structure is a dominant design factor inLaminates can be defined with considered automatically and clearly the discontinuity location while theESAComp FE export, and the defini- displayed. truck is decelerating.tions override the default material ANSYS, Inc. technology and ESA- The ANSYS ESAComp post-definitions. Comp are complementary tools used processing utility indicates to designers Currently, the best way to simulate routinely in developing products made the weakest point of the structure,complex composites structures is to of high-performance composites. The the weakest ply in that location andimport computer-aided design (CAD) technologies were instrumental in the the most likely mechanism of plygeometry in ANSYS Workbench as design of the 75-foot Wally-class failure. This information gives userssurface bodies and use enhanced racing yacht, for example, which valuable insight for making informedcontact features, automated meshing features a unique canting keel for decisions on refining the design ofand environment commands. Then, balancing the moments produced by the structure. ■open the simulation model in ANSYS the sails. In this application, the weightMechanical software and read in all of the boat was a dominant designwww.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 9
  12. 12. CONSUMER PRODUCTSHair TodayProduct developers in the cosmeticsindustry can put simulation to use inperforming hierarchical analyses of haircare product performance.By Aniruddha Mukhopadhyay, ANSYS, Inc. Simulation of water flow rinsing process using head-scale modeling In the consumer-driven world of associated with surface tension,cosmetics, consumer experience and greasiness with viscosity and resultingexpectations are anything but an exact glossiness with optical reflectance. Asscience. Qualitative performance simulation progresses and correlationstesting, to gather information such as are developed, product developers“Does this product increase hair’s also need to understand how and whatshine?” or “Does this product spread to model on various scales.through the hair well?” usually is Consistency in simulation is onlyachieved through subjective testing. as reliable as the details of physicsAs an alternative to such testing, and chemistry in the models. Within aproduct developers and researchers predefined scope, simulation providescan use computational fluid dynamics controlled test conditions. For exam-(CFD) coupled with appropriate ple, a simulation-driven test proceduresurface science and emulsion decom- could be set up to begin with a knownposition mechanisms for virtual testing test subject, possibly developed withinof hair care products. a “hair library” in the simulation soft- ware, of specified morphology, age, Simulation of shampoo concentration contours pore size, moisture absorption proper- using head-scale modeling ties, temperature, and grease in and on the hair. The researcher then could define the environment around the test material (a sample hair assembly or tress) and apply the product making various assumptions, such as the choice to define application such that it yields approximately a uniform layer on the head. More detailed options include an applicator or a fingertip for studying the spreading and coating.Illustration of subjective test results representation for Varying size and scope of thetwo hair care systems CFD model can provide insight for In order to mimic the subjective behaviors that are best observed ontest procedure, a standard (baseline) various scales. Product applicationhair with the standard (baseline) and spreading can be accuratelyproduct can be simulated at the outset modeled on a relatively large “head-to establish quantitative correlations scale,” while functions such as glosserbetween subjective characteristics and binding, which actually occur at thechemical or fluid properties. Examples hair surfaces, are best modeled at a Simulation of water velocity contours using head-scale modelinginclude the measurement of tackiness much smaller “hair-scale.” An effective10 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  13. 13. CONSUMER PRODUCTSSpread of a complex oil droplet over a pair of cross-hairs: on the left, initial state in which ingredients suspended in the product’s emulsion are represented as sub-droplets in thelarger drop; on the right, the state after spreading has occurredoverall modeling approach involves chemical potential, temperature and dissolution kinetics, pretreated hairs ascoupling external flow with micro- phase-equilibrium of different immis- well as conditioner ingredients greatlyphenomena near the hair surface. With cible and dissolving ingredients pose affect surface forces on the productthis method, based on the large-scale the design challenges to product drop that is being decomposed andflow conditions, the model is used to developers. To understand the product spread.extract useful hydrodynamics data breakdown process that occurs during The embedded constituents candown to microscopic fluid volumes application, a hair-scale simulation be further defined to have their ownnear a single hair and locally evaluate is required. specific material properties. For exam-performance of various agents. This To examine the emulsion decom- ple, they could be defined as wettable,would enable gathering detailed position process, a complex, multi- which means they stick to the hair,information about the effectiveness of phase simulation is performed. A drop thereby serving as active depositionfactors such as grease removal rate of the specified product is deposited at sites for various ingredients. In aor product decomposition, which is a location at which two hairs cross. case involving ingredients that arerelatively difficult, if not impossible, to The drop being modeled is about three responsible for “hold” qualities, theconsistently observe through tress- times the hair diameter and includes sub-droplets could be defined asbased tests. suspended sub-droplets intended to polymers that will undergo glass tran- Hair care products usually are represent the elemental ingredients in sition, leading to a firmer film at roompackaged as emulsions, multi-liquid the emulsion. The simulation demon- temperature. This film structure willdispersions with suspended ingredi- strates the capillary effects of the provide added elastic strength for theents that don’t segregate while stored. cross-hair assembly and provides the hair strand and evolve as a holdThey are designed to dilute and break product designer with information on quality. One complexity for these filmsdown when applied to the head with the state of decomposition and spread is that they will neither be exactlyeither fingers or a stream of shower. of the product that will occur on such homogeneous in content nor haveVariations in properties such as cross-hair configurations. Due to a isotropic properties for factors such asdensity, rheology, surface energy, variety of governing physics and the elasticity, smoothness or thickness. It is possible to set up a range of simulations for different starting compositions, sizes, temperatures and environmental dilutions and then to observe the final state for each distinct model. Although each simulation will predict a single resulting state, as though the product is in fact homogeneous and isotropic, a heuristic compilation of multiple simulations can together provide a more realistic statistical representation and charac- terization of the relative performancesDynamic simulation of long hairs in a liquid stream of various formulations. ■www.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 11
  14. 14. AUTOMOTIVEThis Volvo hauler truck is equipped with a lightweight aluminum Alutip tipperbed that tilts back to unload vehicle contents. The unique semicircular bed isdesigned by Axis Developments Ltd.Heavy-Duty LightweightAn innovative aluminum design gives a truck-body manufacturer thecompetitive edge in the worldwide construction industry.By Mauritz Coetzee In developing hauler trucks, every and there is the additional desire toAxis Developments Ltd. extra pound of vehicle weight increases get new designs released quicklyPretoria, South Africa manufacturing costs, lowers fuel without numerous physical prototype efficiency and reduces vehicle payload testing cycles. capacity. So Axis Developments Ltd. In redesigning an existing tipper had an idea for making one of the body having a capacity of 15 cubic largest parts of the vehicle out of light- meters, Axis addressed these issues weight aluminum: the tipper body bed upfront in the design cycle with software that tilts back to unload soil, rock, from ANSYS, Inc. by readily evaluating debris or other contents. stress levels for different configurations. A designer and manufacturer of Geometry of the existing design was trailers and truck bodies for the world- imported from Autodesk Inventor, a wide highway transportation and computer-aided design (CAD) package, construction industries, South Africa– into ANSYS DesignModeler software, based Axis is known for its Alutip series which has functions for preparing design of aluminum tipper beds, which weigh models specifically for simulation. The considerably less than comparable engineering team used a mid-surface steel bodies. Developing these struc- extraction tool in ANSYS DesignModeler tures is an engineering challenge, to convert the solid model of the tipper however, since body strength must be body’s 10-mm-thick plates to a simpler maintained with aluminum material, surface representation. This simplifi- which has different properties than cation enabled the software to model the steel; the amount of material must be structure with a minimal number of shell minimized as much as possible for elements for greater solution speed further reduction in weight and cost; while still retaining information on plate12 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  15. 15. AUTOMOTIVE strength needed for higher payload capacities — a benefit for customers and, thus, a definite competitive advantage for Alutip in the hauler truck market. The material cost savings paid for the company’s software investment within only 10 truck bodies. Axis Developments’ engineers had no previous experience with finite element analysis, yet they were pro- ductive after only two hours of training. The tipper body design was completed in less than two days, which would have been unfeasible using conven- tional hand calculations. Moreover, the design was refined with fewer hardware prototypes. Reduction inUsing aluminum materials saves weight but presents a new set of challenges. The first step in redesigning the tipper prototype testing was a huge benefit,body was importing existing geometry into ANSYS DesignModeler software. Axis Developments’ engineers modeledthe truck body with shell elements and parameterized so models could be readily modified by changing a few key since these large structures areparameters, instead of rebuilding the entire model from scratch. extremely time-consuming and expen- sive to build and test. With the success of this tipper body redesign, Axis Developments now uses a simulation-thickness throughout the simulation. traditional support beam configuration based product development approachAdditionally, the model was parameter- could be replaced with a more effec- in which all new design concepts areized so engineers could quickly modify tive semicircular design having a evaluated, “what-if” scenarios arethe geometry of the model by reinforced rib structure and end plate studied, problems are fixed andchanging only a few key parameters, for additional stiffness. As the only designs are refined before detailedinstead of having to rebuild the entire manufacturer employing this unique CAD work is started. ■model from scratch. design shape, the Axis bodies are Next, design geometry passed easily recognizable on the road and The authors would like to acknowledge thefrom ANSYS DesignModeler to ANSYS quickly are becoming the company’s efforts of SolidCad (www.solidcad.co.za), aProfessional software for structural trademark. Body weight was reduced South Africa reseller of ANSYS, Inc. productsanalysis. Since the two modules both 25 percent yet provided the additional that provides software and training.operate on the ANSYS Workbenchplatform, transfer of data occurredwith a menu pick, allowing switchingbetween design and analysis withouthaving to open and close differentapplications. In this way, Axis Develop-ments’ engineers quickly developed amesh and performed stress analysis inANSYS Professional software; theythen were able to appropriately modifythe geometry in ANSYS DesignModelerand immediately perform anotheranalysis to ensure that stress concen-trations were eliminated. Using this approach, engineersquickly arrived at an optimal designby performing three iterations, with atotal solution time of only five minutesper iteration. By experimenting withdifferent types of designs, AxisDevelopments determined that the Stress distribution contours (from ANSYS Professional software) plotted on the Axis tipper body structurewww.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 13
  16. 16. POWER GENERATIONGassing Up with CoalA two-fluid multiphase model allows for moreaccurate simulation of coal gasification.By Christopher Guenther, U.S. Department ofEnergy, National Energy Technology LaboratoryWest Virginia, U.S.A., and Shaoping Shi andStefano Orsino, ANSYS, Inc. Riser The technology of coal gasification Mixing zonehas existed since the early 19th century.Prior to the discovery of natural gas, Coal Sorbentcoal was used to produce so-called Air“town gas” for lighting and heat in cities Steamacross the United States and Europe. StandpipeSpecifically, the gasification process is Coalused to convert any carbon-containingmaterial into a synthesis gas, or syngas. Recycling solids AirSyngas contains mostly carbonmonoxide (CO), carbon dioxide (CO2) Air/O2 steam Air/steam/O2and hydrogen (H2) and can be used as afuel to generate electricity or as a basic PSDF gasifier schematics (left) and an exploded view of the mixing zone (right) colored by contours of CO fractionchemical building block for a large num-ber of applications in the petrochemical fluid dynamics (CFD) using the generation industries for years. However,and refining industries. Gasification Euler–Lagrange, or discrete phase, new reactor designs to improve per-thus adds value to low-rank coal model approach [1]. For fluidized-bed formance, reliability and safety havefeedstocks by converting them into gasifiers however, Eulerian–Eulerian been slow to emerge due primarily to themarketable fuels and products. Due to (E-E), or two-fluid multiphase, model is lack of understanding of the complexmore recent technological advances, the most appropriate approach. The hydrodynamics of the gas and solidgasification offers one of the most effi- E-E model treats the solid phase as phases.cient and cleanest ways to convert the a distinct interpenetrating granular The idea of describing fluidized bedsenergy content of coal into electricity, “fluid” and is the most general- and CFBs with two-fluid hydrodynamichydrogen, methanol and other usable purpose multi-fluid model. models has existed since the earlyforms. Transport gasifiers are based on 1960s [2]. Even with today’s powerful Based on the mode of conveyance circulating fluidized–bed (CFB) reactor computers, numerical solutions of large-of the coal and the gasifying medium, technology and have the ability to scale CFBs are rarely found in thegasifiers can be classified into fixed- achieve higher throughput, better literature, and even fewer that consideror moving-bed, fluidized-bed, and mixing, and increased heat and 3-D solutions [3]. Fortunately, the E-Eentrained-flow reactors. Entrained-flow mass transfer rates compared to modeling approach is one that can helpgasifiers are normally dilute-flow with other conventional technologies. CFB researchers understand the complexsmall particle sizes and have been suc- reactors have been an established interactions between the gas and solidcessfully modeled with computational technology in the chemical and power phases and aid engineers in the design of new reactors. This approach can pro- vide detailed 3-D transient information inside the reactor that otherwise could not be obtained through experiments due to the large scale, high pressures and high temperatures involved. To gain more insight into the process phenomena, ANSYS teamed with the U.S. Department of Energy’s National Energy Technology Laboratory (NETL) toVisualizations of the flow in the mixing zone of the PSDF gasifier for a case with air-blown and steam-enhanced lignitefuel. Included are flow pathlines colored by CO fraction (left); velocity vectors on isosurfaces of solid fraction of 0.2 and develop different CFD models for simu-0.3, in which the formation of particle clusters can be seen (center); and contours of carbon reaction rate (right). lating coal gasification applications.14 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  17. 17. POWER GENERATION -29 -34 -39 -44 Mass flux at outlet (kg/s) -49 inlet -54 The basic design of the PSDF -59 transport gasifier included a mixing zone, -64 which kept the recycling solids present long enough for the carbon left in the -69 outlet particles to react with the incoming gas -74 (O2, steam or CO2). Visualizations of the -79 system interior showed that the flow was 260 270 280 290 300 recirculating and mixing in the mixing zone t (s) before it moved up into the riser section, Fluctuations of the mass flux (including both solid and gas) at the gasifier outlet. The negative value represents the outgoing flow at the outlet. The magnitude of these fluctuations can deviate and also that local conditions were very by as much as 70 percent around the mean of – 47.12 kg/s. chaotic and turbulent. At the bottom of the mixing zone, combustion of the carbon present in the recycle material depleted the available O2. Further combustion occurred as the solids moved up higher into the mixing zone. At the same time, Model other reactions such as CO and H2 Height Exp. combustion were competing for the O2. These exothermic reactions generated the necessary heat for the endothermic reactions, including steam gasification and CO2 gasification of carbon. The research team validated the over- all computational results against PSDF 1300 1350 1400 1450 1500 1550 1600 Temperature (F) experimental data for both bituminous Time-averaged temperature distribution along the PSDF center line as compared to experiment and sub-bituminous coals under both air-blown and oxygen-blown conditions. The computational difference between theTheir objective was to illustrate how CFD In the FLUENT simulation of the mass flux at the inlet and average masscan be used for complex large-scale PSDF, 11 species were included in the flux at the outlet was only 0.1 percent,geometry with detailed physics and gas phase while four species were which meant that the mass was balancedchemistry. Using FLUENT software, the assumed to be in the solid phase. well from the simulation standpoint. Theteam developed a 3-D transient model of A total of 16 reactions, both homo- team drew the same conclusion for theKBR, Inc.’s Power Systems Development geneous (involving only gas phase heat balance. For the temperature profile,Facility (PSDF) transport gasifier. KBR is a species) and heterogeneous (involving the difference between the simulation andglobal engineering, construction and species in both gas and solid phases), measurement was due mainly to theservices company that has partnered were used to model the coal gasifi- location of the probes relative to the centerwith other companies to build a com- cation chemistry. The gas combustion line. Despite the finding of very unevenmercial transport gasification unit, based reactions were simulated with a finite- temperature distributions at any givenon the technology developed from the rate combustion model. The coal cross section, the overall trends ofPSDF, at a 285-MW power generation reactions, including moisture releasing, the temperature profiles were in goodfacility in Florida that promises to be the devolatilization, char combustion, char agreement with the measured data. ■cleanest coal-fueled plant in the world. gasification, tar cracking and water– gas shift reactions, were modeled with References 20 a heterogeneous reaction scheme and [1] Shi, S.; Zitney, S.; Shahnam, M.; Syamlal, M.; 18 a set of user-defined functions. The Rogers, W., Modeling Coal Gasification with CFD 16 and the Discrete Phase Method, 4th International Model geometry was meshed with 70,000 Conference on Computational Heat and Mass 14 Exp. cells, and each simulation case was Transfer, May 2005, Paris. 12 run in parallel on an eight-processor [2] Davidson, J., Symposium on Fluidization —% 10 8 machine. Post-processing the data Discussion, Trans. Inst. Chem. Eng., 1961, 39, 6 was done once the solution reached a pp. 230-232. 4 pseudo-steady state, which required [3] Guenther, C.; Syamlal, M.; Shadle, L.; 2 Ludlow, C., A Numerical Investigation of an running the simulation until it gener- Industrial Scale Gas–Solids CFB, Circulating 0 CO H2 CH4 CO2 H2O ated physical data representing about Fluidized Bed Technology VII; Grace, J.; Zhu, J.;Outlet gas composition for the PSDF transport gasifier 40 seconds of time. de Lasa, H., Eds.; CSCHE, Ottawa, 2002, pp.as compared to experiment 483-488. www.ansys.com ANSYS Advantage • Volume I, Issue 2, 2007 15
  18. 18. PROCESS EQUIPMENTChopping Awayat SolidsCFD simulation provides a pumpcompany with a virtual test facility.By Glenn Dorsch and Kent Keeran Geometry of a typical casing, impeller and cutter bar assemblyVaughan Company Inc., Washington, U.S.A. Chopper pumps utilize a pumped liquid contains solids that need to pass through the chopping action between pump without clogging or plugging. the impeller and the suction The benefit of a Vaughan chopper pump over a typical plate to break down solids non-clog or slurry pump is that it reduces the solids size of that pass through the pump material passing through the pump. The unique chopping into smaller pieces. Vaughan requirements and suction arrangement of these pumps Company, an established make it difficult to apply standard impeller design practices pump manufacturer in in order to evaluate hydraulic performance. As energy costs Washington, U.S.A., designs continue to rise, developing more efficient pumps becomesIn a Vaughan chopper pump, the main and manufactures a line of increasingly critical for all pump manufacturers. Vaughanimpeller vanes extend all the way to the centrifugal chopper pumps. Company found that simulation was an effective andcenter hub of the impeller, and the suctionplate includes two stationary fingers that These pumps originally were efficient way to approach the optimization of pump design.protrude to the center of the suction designed in the 1960s for use Vaughan Company’s simulation process begins byopening. As the main vanes pass by thestationary fingers, a chopping action in the local dairy industry to importing computer-aided design (CAD) models fromresults, which macerates any solids transport manure to and from Pro/ENGINEER® into ANSYS DesignModeler software. Theentering the pump. storage tanks. Since then, impeller domain and casing domain are meshed separatelyVaughan chopper pumps have been refined continually and and assembled within the CFX pre-processor in whichawarded a number of patents; the company has earned wide boundary conditions are applied. The ANSYS CFX solveracceptance for many applications that require solids performs the required calculations; then, results arehandling. Today, Vaughan chopper pumps are used in viewed and pump performance is calculated in the compu-various phases of municipal and industrial sewage treatment, tational fluid dynamics (CFD) post-processor. The ANSYSfood processing, and pulp and paper industries, in which the Workbench platform facilitates the entire simulation process, from geometry import through visualization. ACTUAL 6U VERSUS SIMULATED 6U @1750 RPM; 11.8 DIA IMPELLER SIMULATED 6U VERSUS SIMULATED 6U @1750 RPM; 11.8 DIA IMPELLER 130 130 120 120 TDH (FEET), POWER (HP), EFFICIENCY (%) TDH (FEET), POWER (HP), EFFICIENCY (%) 110 110 100 100 90 90 80 80 70 70 60 60 50 50 1100 1300 1500 1700 1900 2100 2300 1100 1300 1500 1700 1900 2100 2300 GPM GPMPerformance curve for a recently redesigned 6-inch pump. The simulation slightly Comparison between the simulated existing impeller and the simulated redesignedunderpredicts TDH because the geometry for the impeller and casing had to be impeller ensured that the redesigned impeller had TDH characteristics that were asreverse-engineered, and there were likely some differences between the model good as the original impeller. The new design achieved an approximately 8-pointand the actual parts. increase in efficiency over most of the flow range.16 ANSYS Advantage • Volume I, Issue 2, 2007 www.ansys.com
  19. 19. ADVANTAGE Spotlight on Engineering Simulation in theBiomedical Industry s2 Making Life Longer and Better s10 Standing Up Right s4 Turning Up the Volume s12 Designing with Heart s6 Hip to Simulation s14 Going with the Flow s7 Walking Pain Free s15 Battle of the Bulge s8 Engineering Solutions for Infection Control SWEET SOUNDS FROM SIMULATION COCHLEAR IMPLANTS