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Online COMSOL Conference 2020 is announced for October 7-8

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COMSOL-53-release-3-croppedCOMSOL has announced that the COMSOL Conference 2020 North America will be held on October 7–8, 2020 in a virtual format. The annual Conference, a meeting focusing on advancing skills and furthering collaboration among engineers and scientists in the area of multiphysics simulation, will for the first time run online. Participants, from the comfort of their own workstations, will be able to experience event highlights, including:

• Invited speakers from industry and academia sharing their experiences using multiphysics modeling and simulation apps
• COMSOL keynotes featuring news and software product announcements
• User presentations showcasing research achievements and innovative design projects
• Panel discussions on simulation apps, heat transfer modeling, and electromagnetics simulation
• Tech Cafés, interactive sessions where software developers and technical product managers take modeling questions directly form COMSOL users
• Minicourses offering learning opportunities for any level of simulation expertise, from introductory to advanced
• Virtual exhibition and poster session

“With recent travel restrictions and social distancing in mind, moving the conference online this year is clearly the best option,” said Lauren Sansone, marketing and events director at COMSOL Inc. “The COMSOL Conference North America will be easy to join online, without travel time or time away from home. We believe that the online conference will be attractive to many, as it will also be easier to fit with a busy schedule and other obligations. As we will miss out on in-person meetings, we will be placing extra emphasis on providing interactive, small group sessions, and one-on-one discussions. An added benefit is that we will also have access to COMSOL’s global pool of engineers, as it will be equally easy for them to join the conversations, from anywhere.”

For event details and registration, please visit: COMSOL Conference 2020 North America.

Abstract Submission for Posters and Papers
The Program Committee for the COMSOL Conference 2020 North America is now inviting abstract submissions for posters and papers on simulation work and applications from users of COMSOL Multiphysics to present at the conference.

The papers and posters accepted for presentation will later be shared with the community through the open-access Technical Papers and Presentations database Technical Papers and Presentations database, with a global reach.

The abstract submission deadlines for the COMSOL Conference 2020 North America are: Early Bird submission by July 17th; Final Abstract submission by August 21st. For information and guidelines for abstract submission, please visit: Call for Papers and Posters.

The conference presentations have a broad scope, and the call for papers includes topics such as:

• AC/DC electromagnetics
• Acoustics and vibrations
• Batteries, fuel cells, and electrochemical processes
• Bioscience and bioengineering
• Chemical reaction engineering
• Computational fluid dynamics
• Electromagnetic heating
• Geophysics and geomechanics
• Heat transfer and phase change
• MEMS and nanotechnology
• Metal Processing
• Microfluidics
• Multiphysics
• Optics, photonics, and semiconductors
• Optimization and inverse methods
• Particle tracing
• Piezoelectric devices
• Plasma physics
• Porous Media Flow
• RF and microwave engineering
• Simulation methods and teaching
• Structural mechanics and thermal stresses
• Transport phenomena

COMSOL
www.comsol.com

 

Look up in the sky, it’s CAD software

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A major CAD vendor is betting the modeling software’s future is in the cloud

By Jean Thilmany, Senior Editor

Onshape set off ripples across the computer-aided design community five years ago when it announced its computer-aided design software would exist completely in the cloud. Last fall, PTC acquired Onshape.

The purchase signals PTC’s conviction that engineering companies are ready to embrace CAD in the cloud. The SaaS model, while nascent in the CAD and PLM market, is rapidly becoming the industry’s best practice across most other software domains, said Jim Heppelman, PTC president and chief executive officer.

By bringing Onshape in-house, the software maker has placed itself ahead of the pack in what the engineering software maker sees as the inevitable industry transition to SaaS, Heppelmann said.

“Today, we see small and medium-sized CAD customers in the high-growth part of the CAD market shifting their interest toward SaaS delivery models, and we expect interest from larger customers to grow over time,” he said.

In the future, CAD sellers may reach unique arrangements with resellers to bring CAD in the cloud to a wider user base, according to one potential reseller.

But PTC isn’t going all-in with the cloud. It will continue to offer its on-premise CAD software, Creo.

With CAD in the cloud, designs reside on the software provider’s secure server —rather than on individual workstations. Because the software is accessed and managed online, engineers and designers can work on their models from any location and on any device. The SaaS refers to a provider’s capability to deliver everything needed to run CAD in the cloud—including the cloud infrastructure and the CAD software itself.

Though other CAD makers do offer some type of cloud capability, it’s generally the capability to check files into and out of an application on a cloud-based server; engineers don’t design directly with cloud-based software on other applications, said Jon Hirschtick, president of SaaS, PTC. Onshape differs in that its software exists fully in the cloud and can be used by multiple users in real-time, he added. (Hirschtick founded SolidWorks in 1993 and then went on to co-found Onshape with another former SolidWorks chief executive officer, John McEleny.)

The everyday cloud
You’re already using cloud technology. That’s almost certain. If you have an email account ending in gmail.com or yahoo.com, if you’ve checked a social media account from your desktop or mobile device, if you’ve streamed a movie via Netflix or Amazon or any other provider, you’re a cloud user. The email, social media, and streaming software exist on the software owner’s server (let’s say Google), as does your little piece of it—like your Gmail email address.

Though it’s been possible to run CAD as a SaaS for the past few years, CAD has always been slower than other large, graphic-intense and complex applications to pivot to new platforms, says Len Williams, content manager at designairspace, which gives engineering companies the capability to run any CAD system in the cloud.

“Last year’s acquisition is a very clear statement that vendors like PTC see cloud as a platform of the future for CAD and for all their other software,” Williams added, calling the acquisition a “Windows-level” move.

“CAD systems were originally based on UNIX running on silicon graphics workstations. Then Windows came along and people were laughing at the thought of using CAD on Windows,” he says. “Now most of the major CAD systems run only on Windows.”

Likewise, the way companies buy their CAD software has evolved, he said.

“We went from the old perpetual model, where you buy the software for a workstation, to today’s subscription-based model, where you rent the software,” Williams said. “The next step is when a CAD vendor is running it for you so don’t have to buy hardware or worry about upgrades.”

Large companies already run CAD in the cloud because of the benefits the delivery method offers, Williams added. The difference is, those companies—the French automotive manufacturer PSA Peugeot Citroen is one example—have the funds to build their own, private clouds. Designers, engineers, and suppliers at those companies can access CAD on the private cloud whatever their location: Tulle, France; Brussels, Detroit, or elsewhere.

Working remotely and sharing with suppliers
For the smaller guys, the cloud can bring the same benefits their larger counterparts already enjoy; mainly real-time working together and version management, Hirschtick said.

“Versioning” is built-in, which means file changes are tracked in a central database in real-time. Because any engineer with permission can access the software from any device with internet connection, engineers in different places can work together on a design, such as a power supply, for example. There’s only one power supply file; Onshape doesn’t copy it. But with cloud, everyone in the world accesses real-time single source of truth database. We’re not passing around copies all over the place, he added.

“If multiple engineers happen to be working on that file at the same time, it’s not a problem. If one engineer rounded a corner and another one drilled a hole, both changes get captured,” Hirschtick said. “If we’re both rounding a corner at the same time, you would see my hand there in real-time—at the same table—and a box around the corner would indicate that another engineer is editing that right now.”

The bigger the team is, the quicker the product development process, as everyone—even suppliers—has visibility into the real-time database rather than a copy of something emailed a week ago.

When the workflows are quicker, engineers have more design time and are more willing to innovate to try new things, he added.

Most cloud service providers automatically update their programs. Thus, IT staff can focus on other tasks and engineers know they are working with the latest version of the applications.

Also, engineers aren’t bound to their workstations. The software exists at one central server while engineers work from many. They can be globally dispersed and can work from home or other locations outside the office.

Smaller companies that scale their workforce and supplier base up and down as projects change also stand to benefit from SaaS CAD software. When suppliers move away from a project, the company can easily suspend their CAD license and use of the CAD system, Williams said.

When the coronavirus began making headlines in early 2020, engineering companies running one Onshape customer with offices in three major Chinese cities particularly welcomed the remote-work capability, Hirschtick said.

“Using Onshape analytics, they showed us where people were working before the virus situation in China,” Hirschtick said. As expected, employees worked at the offices in the three major cities.

“Then they showed a map of activity of first two weeks of virus quarantines and lockdowns in China,” he added. “This time there were 20 little circles in regions all over in China. They could see where their employees logged in remotely.

“It doesn’t matter if employees are caught at home with only an Android tablet, they can still do their work,” Hirschtick said. “Even with the phone they can even do some of their work.

There are cases where running CAD in the cloud just doesn’t make sense. Some companies may use CAD only a small amount of time and will do better essentially renting a CAD program, perhaps through the cloud, Williams said.

With cloud-based systems, issues of total cost of ownership and return on investment are generally murky because companies want to see how cloud applications compare to traditional on-site infrastructure.

“But there are so many intangibles wrapped up in the cloud that it makes it hard to put calculations on it,” said Andrew Sroka, CEO at Fischer International Systems, which helps companies manage identities for on-premise and cloud-based applications. “It’s important to factor in expenses like utility costs and power requirements.”

If you can’t buy, rent
With CAD in the cloud being not if, but when, designairspace has new ways to bring benefit to users and CAD makers; reselling vendor software in the cloud. The company would offer customers workstations with major CAD vendor’s programs already installed. Designairspace can track use, which allows the vendors to charge based on time spent using the programs.

“It would be just like mobile phone plans back in the day, where you buy a plan based on minutes. We can do this with CAD in the cloud,” Williams says. “Let’s say you buy a plan with 500 minutes. If you need it for only one or two days a week, you can buy it in a small, affordable plan that’s a small portion of what it would cost you to buy the software.

“Why limit CAD-in-the-cloud to large companies? In the olden days, only big companies could afford 3-D CAD systems. We want small companies to have cloud benefits,” he added. “They would still need to buy their own licenses, but at least they can run it in the cloud, like the big guys.”

The pricing model would benefit companies with project managers or suppliers who don’t design in CAD but log onto the program intermittently.

“These people use the software only a little bit at a time, so we can price it so it’s not so expensive for them,” Williams said. “This is a whole new market for major vendors.”

Becoming a CAD-in-the-cloud reseller and offering online training in those CAD programs is the “next step” for designairspace, he added. With the business model, potential customers can also receive on-the-spot, specialized training if needed and can test the software to see if it’s right for their needs before buying a priced plan, he said.

Or, engineering companies might choose to run hybrid CAD, in which they host some CAD systems at workstations on-premise and buy CAD in the cloud subscriptions for intermittent users, Williams said.

“That way you can gradually move more and more users to the cloud. You can move one or two and see if it works and if it does move more to the cloud,” Williams said. “The heavy users will never move to the cloud.”

That brings up another point. Workstations that run CAD will always be with us, he added.
Companies that do work for the defense department or for the military must do their engineering work on company workstations. They cannot work remotely, Williams said.
For his part, Hirschtick is dreaming big. He expects widespread cloud adoption for CAD as users begin to see the advantages.

“People think cloud tools don’t have the power or speed but that’s an old fable. Cloud tools have more advantage and speed, it’s not a fair fight,” he said. “With desktop tools, you have one CPU sitting on the desktop. With the cloud, we’re able to use unlimited amounts of CPUs. I gave a demo and opened up ten models with thousands of thousands of parts on Macbook in Chrome on a web browser. There’s no CAD workstation that could open them that fast, even the best desktop configuration.

“In a few years, people will be saying ‘how did you ever do CAD on a desktop. How was it fast enough?’” Hirschtick says.

While the future remains cloudy, PTC is backing clearing skies for CAD in the cloud. With a large CAD maker backing SaaS, expect to see a flurry of news and updates. In other words, don’t delete your desktop program.

PTC
www.ptc.com

Designairspace
www.designairspace.com

Additive manufacturing used for local PPE solution in Belgium

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Bruce Jenkins | Ora Research

“Over the last month or so, the Coronavirus or COVID-19 pandemic has captured our collective consciousness across the globe and forced us to rethink every aspect of our professional and personal lives,” says Kaustubh Nande, Global Marketing Director at Hexagon’s| MSC Software. “Hexagon too has taken some concrete steps to protect our workforce and to minimize risk to the supply of our products and our services to our customers. For instance, we put in place a work from home program to use our smart manufacturing software packages and put together additional online learning options for manufacturing professionals.

“One interesting project undertaken by our team in Belgium was about using in-house knowledge and available material and tools to solve a specific issue posed by the COVID-19 outbreak. Across the globe, there have been several reports of hospital workers suffering from shortages in Personal Protective Equipment (PPE), due to the unprecedented demand across the world.”

The Hexagon | e-Xstream team at Belgium “heard about a requirement for PPE, specifically face shield holders, in a nearby hospital. The team decided to chip in and do its bit by conceptualizing an additive manufacturing solution to the problem. The team had access to a 3D printer and suitable material within the office. The team first found an open CAD model that was available online and plugged it into the 3D printer and used the design to 3D print some face shield holders right at the Hexagon office.”

The company says that, “backed by a thorough understanding of additive manufacturing techniques and knowledge about the use of Digimat and e-Xstream in plastic printing, the team was able to think smart and deliver on what the doctors required. In the coming weeks we will also be increasing the production count. The finished product met the need for equipment that could protect hospital staff. The key thing is these plastic PPE liners can be disinfected easily and reused by the hospital. Depending on material available you can print in various colors for easy identification.”

MSC concludes, “This gesture by our Belgium team stands out as a great example of how the right hardware and software tools combined with the proper knowledge can bring in quick, practical solutions to solve real-life issues quickly and effectively.”

Work-from-home information

MSC adds: “Our customers, employees, and partners are at the heart of what we do. Our concerns and well wishes go out to all those directly and indirectly affected by the COVID-19 pandemic. We are taking the threat very seriously by protecting our workforce and minimizing the risk to the supply of our products and services to you during this time. Across the globe, the measures being put in place to reduce the spread of COVID-19 means that many companies are asking their employees to work from home.

“Our goal is to offer the level of responsiveness and support that you have come to expect from MSC. If there is anything we can help you with, please do not hesitate to contact us. Please visit mscsoftware.com/work-from-home/assistance-programs for complete details on our current assistance programs, as well as check back for additional announcements in the coming days.”

Kaustubh Nande

Hexagon’s COVID-19 information page

Reduce overall simulation time

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Siemens Digital Industries Software announces the latest release of its Simcenter FLOEFD software, a CAD-embedded computational fluid dynamics (CFD) tool. Simcenter FLOEFD is part of the Simcenter portfolio of simulation and test solutions that help engineers simulate fluid flow and thermal problems quickly and accurately within their preferred CAD environment. The latest version offers new modules and improvements that can improve accuracy and solve rates.

The software helps users frontload CFD simulation early into the design process to understand the behavior of their concepts and eliminate the less attractive options. The software can reduce overall simulation time by as much as 65-75% and offers up to 40 times user productivity enhancement. Part of the Xcelerator portfolio, Simcenter FLOEFD also helps design engineers contribute to the creation of a highly accurate digital twin.

The new Electronics Cooling Center module combines existing best electronics-specific capabilities and integrates new ones from Simcenter Flotherm software inside the CAD-embedded interface to enhance electronics cooling functionality. A second new module helps users create a compact Reduced Order Model (ROM) that solves at a faster rate, while still maintaining a high level of accuracy. The Power Electrification module can now simulate an electrical device as an electro-thermal compact model, which can save significant user and computational time.

Siemens Digital Industries Software
www.sw.siemens.com

Predict how materials and manufacturing methods affect design

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e-Xstream engineering, part of Hexagon’s Manufacturing Intelligence division, unveiled a new 10X Integrated Computational Material Engineering (ICME) Solution that applies academic research with leading software and inspection solutions to accelerate innovation by enabling manufacturers to design, engineer and test components virtually through simulation.

With ICME, designers can work with materials such as carbon fibre composites and use them to their full potential through material simulations with better data and modelling. 10X ICME leverages the full potential of ICME. Using 10X ICME, it is possible to predict how combinations of materials such as composites and manufacturing methods from injection molding to 3D printing will affect everything from the speed to the sustainability of future designs, such as aircraft and cars. It reduces the amount of materials testing required and correlates measurement with simulation so manufacturers can more easily validate simulations. In addition, because materials data are made readily available, engineers can apply accurate values to make optimal designs rather than relying on approximations.

The digital integration of end-to-end supply chains will also cut material waste by reducing dependence on extensive real-world prototyping and over-design. A single material-centric ‘digital twin’ of the entire manufacturing line from material development to final part performance helps organizations predict the performance of end products at concept stage. It also presents opportunities for data-driven customization of materials for specific purposes such as recyclability or energy-efficiency.

10X ICME helps new technologies such as lightweight blended wing airliners or ultra-quiet electric vehicles be developed faster. The solution is already being used by a major aerospace and automotive original equipment manufacturers (OEMs) to accelerate the rate at which new designs can be brought from concept to reality. Initial customer projects using this new approach are being completed in half the time and at a third of the cost.

There are 10 pillars within the 10X ICME solution, which combine the different ICME technologies from the ecosystem to address specific use cases. Manufacturers can choose the pillars most pertinent to them today and mold their solution to their needs as the disciplines and processes evolve.

10X ICME draws on cutting-edge material science research, Hexagon’s metrology, software and e-Xstream engineering material simulation technologies. It integrates the supply chain of materials suppliers, software tools, manufacturing equipment and metrology.

Hexagon | e-Xstream engineering
e-Xstream.com
hexagon.com

MSC pivots business model so engineers can continue innovating anytime and anywhere during COVID-19

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MSC Software Corporation (MSC), a global leader in Computer-Aided Engineering (CAE) simulation software and services and part of Hexagon’s Manufacturing Intelligence division, has announced that it will provide its customers with free offline licensing and remote access options to help them remain productive while working from home as COVID-19 closes customers offices globally.

In the past, remote working has posed a challenge for the manufacturing industry, with many of its tools and processes being rooted in old-fashioned workflows. The COVID-19 mitigation measures, which have led to vast swaths of the engineering workforce forced out of the factories and offices, have driven the need for a more flexible, distributed mode of operations.

Computer-Aided Engineering and simulation tools can support this evolution, and MSC’s customer-centric move to flip their licensing model to allow for use in the home is proof in point.
Roger Assaker, Chief Customer Engagement Officer of MSC Software, said: “We are adapting to the needs of our customers, and are also adding a helping hand to support their business continuity so they can continue to design, engineer and perform virtual testing outside their place of work. We are facilitating the access to our software, knowledge base and support to enable the creation of even more value with our tools, helping companies to maintain productivity and innovation when many manufacturing lines are down.

“We appreciate that these are very challenging times for many of our customers, and we can guarantee that we will be supporting them to the best of our ability, every step of the way.”

The offering from MSC Software includes:
• Extension of licences for work-from-home support or alternative access options for MSC Software CAE solutions
• Free access to online learning for MSC Software solutions

Hexagon | MSC Software
mscsoftware.com

Improve simulation time and accuracy

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The latest release of Simcenter™ STAR-CCM+ software, part of the Simcenter portfolio of simulation and test solutions for optimizing design, includes improvements to simulation time and accuracy, and enhanced collaboration. These features give customers a comprehensive digital twin to drive predictive simulations. In this release, Siemens is introducing a new parallel polyhedral mesher for faster, more effective meshing, as well as a model-driven adaptive mesh refinement (AMR) solution. The latest release also includes automatic coupled solver control for reduced set up time. Convergence speed is improved through a collaborative virtual reality (VR) feature in a CFD code for enhanced team collaboration on simulation results.

The fully-rewritten parallel polyhedral mesher builds meshes up to 30 times faster than in serial, for a consistent mesh regardless of the cores used and a more effective mesh distribution with the same accuracy and robustness. New adaptive mesh refinement (AMR) technology intelligently refines the mesh based on the physics. This can lead to less user interaction as well as computational overhead and reduces overall mesh size.

Collaborative VR in Simcenter STAR-CCM+ allows teams across the globe to interact in the same immersive virtual environment in real time, enhancing communication and decision-making. Multiple VR clients can now be connected and synchronized to the same simulation, with avatars showing the location of other users and providing the ability to tether users to get the same experience.

Simcenter STAR-CCM+ is an integrated solution for computational fluid dynamics (CFD) and multiphysics simulation that brings automated design exploration and optimization within the grasp of all simulation engineers. Simcenter and Simcenter STAR-CCM+ are part of Xcelerator portfolio, Siemens’ integrated portfolio of software, services and application development platform.

Siemens Digital Industries Software
www.sw.siemens.com

Multiphysics for IronCAD 2020 released

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IronCAD, a leading provider of design productivity solutions, announced the immediate availability of the latest version of its fully integrated Multiphysics for IronCAD (MPIC).

Since the unveiling of Multiphysics for IronCAD, the usability and robustness of MPIC have been appreciated by many IronCAD users. Each year, additional improvements and refinement have been added to further increase the ease of use as well as the functionalities that sets it apart from the competition. Most of these new features are based on user feedback and requests to speed up the design cycle, simplify analysis setup, and reduce analysis times.

MPIC 2020, includes several new and improved key technologies designed specifically for CAD design analysis. IronCAD’s focus was on general CAD designers and users who want to adopt design analysis earlier in the digital prototyping cycle and aim to provide accurate, realistic and quick analysis. As such, most of these improvements are in the assembly analysis functionalities.

Some of MPIC 2020 new technologies and features include:

• New tolerance assembly analysis technology is implemented with respect to how parts are assembled and meshed for analysis. This new option uses parts’ discrete boundary surface facets to smartly unite parts together for design analysis. This technology enables the healing of CAD assembly models with intentional or unintentional gaps so they can be glued together for quick design analysis.

• New drag-and-drop user interface has been implemented in the part tree of materials, boundary condition constraints, and load areas. Users can select the part’s tree node and drag it to a different material tree to quickly assign it to a different material. In boundary condition constraints and loading, the sequence of the priority of the constraint can also be changed by selecting the condition and drag it up/down to change the priority of the boundary condition.

• MPIC model is now upgraded to XMD 2.2 model and compatible with all AMPS product lines. It can be opened, modified, and analyzed by any AMPS XMD application if additional features/capabilities are needed.

Multiphysics for IronCAD offers basic to advance versions that include non-linear, fluid, dynamics, and rigid body kinematics. Once installed, users have access to the full functionality limited to 2000 mesh nodes that can be used to get started with the analysis application. You can access the latest Multiphysics for IronCAD 2020.

“This new release with new tolerance assembly analysis technology will streamline the design analysis for design engineering beyond anything in the market today” stated Cary O’Connor, V.P. of Marketing of IronCAD. “Users will be able to quickly design products and assemblies with accurate design simulation easily without having to struggle with gaps and inaccuracies often found in CAD designs that don’t fully model manufacturing processes such as welds and fixturing. Overall, users can improve designs and design-to-product times with this new functionality” he continued.

Dr. Ted Lin of AMPS Technologies, developers of MPIC, and meshing technology partner Dr. Mark Beall, President of Simmetrix Inc. says, “For more than three years of development and testing, our team has taken on this task to resolve this well-known problem in CAD models. This new technology gives the user more control over gluing together parts in assembly models with intentional or unintentional gaps for quick design analysis that virtually eliminates the CAD modeling inaccuracy issues that users struggled to resolve in the past.”

IronCAD
www.ironcad.com

Latest Simcenter 3D enhancements deliver better insight into product performance

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Siemens Digital Industries Software announced the latest version of Simcenter 3D software, part of the Simcenter portfolio of simulation and test solutions. Simcenter 3D helps product engineering teams be more productive and produce consistent simulation results with a unified, easy-to-use shared platform covering most simulation disciplines. The latest version delivers the most comprehensive, fully-integrated CAE solution on the market today, to help optimize design and deliver innovations faster and with greater confidence.

The latest release of Simcenter 3D includes many improvements in four key areas:

Multidiscipline Integration: Simcenter 3D offers new simulation methods that increase realism and deliver better insight into product performance. Industrially validated rotor dynamics simulation capabilities have been extended, to include nonlinear connection elements, for example, allowing engineers to minimize rotational unbalance and unnecessary external forces in applications such as aircraft engines, gas turbines, automotive engines, industrial equipment, and even electronics, for example when computer disk drives spin at high rates.

Improved Simcenter 3D rotor dynamics simulation solutions allow you to minimize rotational unbalance and unnecessary external forces in applications such as aircraft engines, gas turbines, automotive engines, industrial equipment, and even electronics.

Faster CAE Processes: New Noise Vibration and Harshness (NVH) composer tool helps engineers quickly create system-level finite-element (FE) models, starting from subassembly models such as an automotive body-in-white, door, suspension, and more. Automating the full-vehicle FE model increases process speed and helps reduce human error.

Ties to the Digital Thread: The seamless integration with data management from Simcenter is extended to enhanced ties to the physical testing group. Deeper test/analysis correlation capabilities from Simcenter 3D, such as new pre-test planning for determining sensor locations, can help determine the best methods to use for physical testing and increase confidence that simulations are accurately predicting real-world results.

Open and Scalable: Simcenter 3D is an open environment where engineers and designers can gain the benefits of faster CAE processes by using Simcenter 3D in connection with other CAE solvers. Added support for cyclic symmetry can help engineers simplify the modeling and simulation process for components when using the Abaqus solver.

Simcenter 3D and the Simcenter portfolio are part of the Xcelerator portfolio, Siemens’ integrated portfolio of software, services and application development platform.

Siemens Digital Industries Software
www.sw.siemens.com

How to combine 1D and 3D thermal simulation for modeling aircraft fuel systems

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Leveraging advanced 3D CAD-embedded CFD capabilities can add robustness and fidelity to a 1D system model.

By Mike Croegaert, Siemens Digital Industries Software

A common issue with modeling complex 1D systems is adding the required detail for complex components that cannot easily be represented through correlations or empirical data. To get the data for these types of components, engineers have two options: physical testing and 3D computational fluid dynamics (CFD) simulation and analysis. Physical testing can be costly and obtaining the data can be difficult for all possible operating scenarios. Whereas, 3D CFD can be time-consuming and often requires an expert to get reliable results.

Fortunately, we now have the option to use advanced 3D CAD-embedded CFD solutions in conjunction with 1D CFD tools to quickly and accurately characterize complex components without the need for a specialist, while providing an added level of robustness to a complex system model.

The basic fuel system: solving pump limitations
To illustrate the effectiveness of using this combination, a simple passenger aircraft fuel system example will be used. Figure 1 shows a 1D system model drawn on top of the basic fuel system schematic image. It includes source components for the boundary conditions and extra loss components for items such as filters and couplings. The thin link lines represent a direct connection between adjacent components, but they are not pipes themselves. Nodes sit in the middle of the links and serve as convenient points to enter elevation data and interrogate flow results of temperature and total pressure.

Figure 1: Basic aircraft fuel system schematic. The three large blue sections represent the wing and the center fuel tanks, the white boxes represent pumps, and the fuel feed and transfer plumbing is represented in green. The refueling lines are represented in dark blue. Shut-off valves are depicted throughout the model as the circular symbols, indicating normally open or closed.

During normal operation, the fuel is drawn from the tanks with mechanical fuel pumps. However, most mechanical pumps must be fully wetted to function properly. This means sometimes unusable fuel is left in the bottom of the tank. To extract the residual fuel, jet pumps can be added with the suction side connected to the lowest sump point on the inner wing tank. This pump feeds the collector cell by using the motive energy provided by a small amount of high-pressure fuel bled directly from the mechanical fuel pumps. For this example, the jet pumps are placed in the lowest portion of the tank.

In contrast to most other components, this jet pump does not come pre-supplied with performance data. That leaves the designer with two options to define performance. The first method is to enter detailed geometry for the pump and the 1D CFD tool can apply a built-in empirical correlation for jet pump behavior. The second option is a more rigorous databased approach. The pump requires a curve of flow ratio versus head ratio and a curve of motive flow rate versus pressure difference between the motive and suction arms. This data can come from many sources, including the vendor of the pump, physical testing, or 3D CFD characterization and analysis.

3D-1D characterization
Sophisticated 3D CAD-embedded CFD programs have key technologies that facilitate 1D data generation. These tools can be used by the typical engineer as well as seasoned CFD analysts. They apply automated modified wall functions to capture boundary layer effects properly, regardless of the density of the mesh in the boundary layer. They also have an automated solver to determine the flow regime between laminar, turbulent, or transitional without intervention. The most advanced 3D CAD-embedded CFD software has a unique and automated mesher that is geometry aware. If the CAD geometry changes, the mesh changes automatically, updating as the problem solves, intelligently putting more mesh where it is needed. Because these tools are completely CAD-embedded, the designer can run parametric studies, by not only varying flow conditions, but also changing the actual geometry over the course of a study, feeding data back to the 1D CFD software as seamlessly as possible.

Using an intuitive graphical interface, the designer inputs the key variables—choosing the units, the physics to consider in the simulation (including heat transfer, gravity effects and rotation), the fluids to use in the simulation, and lastly, the initial conditions such as temperature, pressure, and initial velocity. The 3D software then calculates a computational domain surrounding the relevant fluid geometry. The design engineer can resize the domain area or even slice the volume in half and do an axisymmetric simulation to save computational resources. The mesh (Figure 2), although highly automated, can be manually driven to add grid cells where needed and manually refined by selecting specific geometry, adding optional control planes, or even disabled bodies into the CAD model to serve as the mesh structure.

Figure 2: 3D CAD-embedded CFD adaptive mesh.

Once the model is prepared, the boundary conditions set, and goals determined, the simulation is ready to run launching the solver. The solver is the only aspect of 3D CAD-embedded CFD that does not operate directly in the CAD environment. Instead, a second window is launched to monitor the progress of the solution. Custom-defined preview plots for parameters such as pressure, velocity, and even the mesh can be created. Goals can also be plotted to have a real-time monitor on current value and their trend toward convergence. Parametric studies can also be performed on multiple machines at once to improve performance.

Once complete, the results are loaded back into the CAD interface, the first example of a result is a cut plot that shows the contours of velocity with overlaid streamlines (Figure 3). The cut plane can be manually adjusted with a live preview. 3D CAD-embedded CFD can also generate three dimensional flow trajectories inside of the fluid region.

Figure 3: Sample results from 3D CAD-embedded CFD.

Typically, for characterizing a component using 1D CFD software, multiple simulations are needed to generate data over a range of flow conditions. Once the study is complete, the results can be saved to a file that acts as a raw record of the flow conditions at each boundary at each experiment point. Each point contains data for flow rate, pressure, temperature, density, viscosity, enthalpy, and heat capacity. From this data, non-dimensional curves can be created so that the software can extrapolate performance of the part over a range of fluids, temperature, and pressures.

After the curves are created, they can be imported into the 1D CFD tool either as an individual data curve or as a complete component. The software will parse the data and automatically determine what type of component to create. Once this step is done, the 1D CFD software adds the component to the catalog and automatically populates it with the data just generated.

Before using the component in the fuel system model, it will first be verified in a unit test. Unlike most components, components sourced from the 3D CAD-embedded CFD program require no further data to use because relevant data such as the curves are pre-applied. All that is required to run a unit test is to add boundary conditions and run an analysis, and the component should perform exactly as the software predicted during the characterization step. After the unit test has verified the component was created correctly, the jet pump can be added to the fuel system model (Figure 4), and the designer can run a series of analyses.

Figure 4: Adding the characterized jet pump to the system model.

In this example, two transient simulation scenarios will be examined. In the first simulation, the jet pump has been included but blocked the motive flow, so the tanks will only feed into the collector cell via gravity. The connection between each section of the tanks is through a series of holes in the ribs that separate each compartment. These holes span almost the entire height of the tank, but the bottom 2-in. of the tank is blocked by structure.

As shown in Figure 5a with the blue line, the outer tank is draining briefly into the inner tank marked in red. The outer tank stops flowing as the level of fuel drops below the holes in the rib. Rendering the remaining 2-in. of fuel in that tank unusable. The inner tank in red, and the collector cell in green both drain together. The collector cell is drained via the mechanical fuel pumps, and the inner tank drains via gravity into the cell until it too reaches about 2 in. of height and can no longer drain. The tank is exhausted of all usable fuel in about 125 seconds.

Figure 5a: Scenario 1 – Jet pump inactive.
Figure 5b: Scenario 2 – Jet pump active.

The second case shown in Figure5b has the jet pump enabled. Here, the jet pump is moving fuel from the inner tank to the collector cell at a rate of about 10 gal per minute. In this case, the inner tank drains much faster, but that fuel is being transferred to the collector cell to feed the pumps. Because the suction inlet to the jet pump can be placed at the lowest point in the tank, it can drain almost all of the fuel out of it before it stops providing flow. At this point, the fuel level in the collector cell starts to drop quickly until it is completely exhausted. In this case, because more fuel is available, the tank does not drain for 320 seconds, a significant improvement.

Leveraging advanced 3D CAD-embedded CFD capabilities can add robustness and fidelity to a 1D system model. The 3D CFD solution does this by characterizing complex components within the CAD environment and then automatically importing the results into the 1D model. Here, a common issue with 1D system models of aircraft fuel systems was examined: how to add the required detail to the model for complex components that cannot easily be represented through correlations or empirical data. Siemens 3D CFD software, Simcenter FLOEFD, runs inside of several CAD packages including Siemens NX and Solid Edge, CATIA V5, PTC Creo, and a standalone version. This example also uses Siemens Flomaster 1D CFD software for the system simulation.

Until recently, designers had to choose between costly physical testing and time-consuming 3D CFD that usually requires an expert to obtain reliable results. This approach that combines 3D CAD-embedded CFD and 1D CFD can be used to quickly and accurately characterize complex components without the need for a CFD analyst and provide an added level of robustness to complex models such as the aircraft fuel system.

Siemens Digital Industries Software
www.sw.siemens.com