Acoustic CAE tools will aid in the electrification of vehicles.
Vehicle Electrification on the Rise
When Coherent Market Insights (CMI) published its report on vehicle electrification, it estimated that the global market would reach $140 billion by the end of 2027. This statistic includes fully electric vehicles (EVs) and hybrids and forecasts growth in every continent. Trends noted in the report include a new focus on safety and comfort beyond the need for the sustainable benefits that EVs provide. Shutdown systems to stop and start the engine during heavy traffic, demand in developing countries where infrastructure in roads and electricity is improving, and partnerships between automotive companies and suppliers were all metrics that CMI showed to be on the rise over the next decade.
The International Energy Agency released its Global EV Outlook 2019 report with predictions pushed all the way out to 2030. The agency took the side of optimism and the Clean Energy Ministry’s EV 30@30 campaign, calling for 30 percent of the world’s vehicle production to be electric by 2030. If this target is hit, then 44 million EVs will be sold in 2030. Big ideas from the report revolve around emissions, policy and the private sector. Fuel economy standards and purchase incentives from the world’s governments have the potential to boost the public’s purchase and adoption of EVs. Private companies are already hurrying to produce technologically advanced batteries, charging points and transmission systems. The report also indicates that over the life of the vehicle, full electric or hybrid vehicles will emit less carbon dioxide than their internal combustion gasoline counterparts. However, in countries where emissions are primarily coal based, hybrids produce less emissions than EVs, and in places where lower carbon energy is produced, EVs will have the advantage. Where the CMI report focuses on general trends and the state of vehicle electrification, the International Energy report centers on using less energy, reducing emissions, and increasing overall sustainability.
Now that the world seems to be in some agreement that we’re moving toward electrification, the idea of comfort comes into play. Some customers might be interested in saving money with an EV and others might be happy to help reduce their carbon footprint and drive sustainably, but automakers are facing increasing pressure to deliver high-end EV experiences. Engine noise and road noise change when the vehicle is electric, and that presents engineers with yet another new set of challenges. Cristian Tangemann from Automotive IQ says that electric vehicle powertrains have fewer parts and much less engine noise, so different vibrations and buzzes around the vehicle now have the potential to be noticed when they were masked before by the internal combustion hum. Engineers might now need to work on road noise but also figuring out ways to mask gears whining or rattling, and different frequencies resonating together.
Hexagon’s Manufacturing Intelligence Division illustrated the partnership trend mentioned in the CMI report, as the sensor and software company recently announced a venture with Autoneum to enhance vehicle acoustic design. Free Field Technologies is the arm of Hexagon known for acoustical and thermal management that will work with Autoneum.
FFT’s Acoustic Transmission Software
FFT’s current software for acoustic simulation is Actran (ACoustic TRANsmission) and its 2021 release boasted a redesigned graphic user interface. The Acoustics module is the stand-alone tool for the software, but additional modules for VibroAcoustics, AeroAcoustics, Trimmed Body and SNGR for turbulent flow are also available. A case study from 2018 titled “Predicting the Acoustic Signature of Electric Vehicle Powertrains” outlined the ways in which the software helped address gear rattle and whine in a gear reducer using multibody dynamics. Another great case study from 2019, “Sustainable Engineering is Good Business Sense: Computer-Aided Engineering Can Solve Global Environmental Challenges” laid out several opportunities for computer-aided engineering (CAE) software to help guide engineering changes, and by extension, reduce the cost and environmental impact of vehicles. Battery thermal analysis can increase fuel efficiency and electric powertrain noise, vibration and harshness (NVH) studies can reduce environmental noise. Optimization to lightweight vehicle body structures aids in fuel efficiency, and advanced driver assistance systems (ADAS) simulation can help optimize traffic flow patterns.
Autoneum’s SILVER and GOLD
Autoneum also focuses on vibroacoustics, in the concept phase, in an effort to reduce time to market. Its GOLD software works with NASTRAN finite element analysis to simulate damping material added to vehicle body panels. Users can instruct GOLD to add beading, ribs and soap films to the model and see FE outputs updated in real time. One example showed 11 variables for the position and thickness of dampening patches, 27 design variables for shape modifications, and the optimized dampening for the vehicle’s flooring reduced by 20 percent.
The SILVER software is the companion module that predicts the shape and ideal location of dampeners in the vehicle body based on finite element single vibration analysis. The software uses a ranking system to show which components can be modified to make the biggest impact and is the choice for doing side-by-side comparisons between two options. SILVER also provides a ranking of the different components to show which changes will have the most immediate impact on design performance.
The Autoneum software suite also includes TREASURI2 for porous materials in the low and mid frequency ranges, REVAMP for studying parts in the passenger compartment using statistical energy analysis (SEA), and VisualSISAB for determining acoustic impacts of components with complex geometries and a variety of different materials.
Putting the Two Together
Both Autoneum and Hexagon issued press releases highlighting the benefits of this new partnership. Davide Caprioli, head of Acoustic and Thermal Management at Autoneum, said that “Autoneum’s simulation tools for vehicle acoustics are already being used successfully by manufacturers and suppliers worldwide. By working with FFT and integrating our know-how into the Actran software, our methodology will now be even more widely and readily available, thus making it the global standard in NVH engineering.”
Meanwhile Diego Copiello, product manager at FFT, added “Hexagon offers market-leading CAE solutions that help identify noise sources and mitigate their harshness. Our collaboration with Autoneum will provide new tools to industry engineers to help them optimize the acoustic design of their vehicles and provide their customers with a quiet and comfortable driving experience.”
Taking two different software suites that both build off NASTRAN and forming a new product feels like a solid idea. While we, as end users, wait for the eventual end product, the heavy lifting is being done internally by the software engineers working to integrate the two systems. These first press releases make it seem like Autoneum’s software will be mapped into the current Actran software. Most of the work here looks at the idea that new noises and vibrations will be dissatisfying to the end customer, but the potential for vibration damage to the vehicle system also needs to be considered. The new software product that will emerge from this partnership doesn’t seem to have a name yet, but Autoneum reports that it will be presented at the 2021 HxGN Live Design and Engineering Event. I’m looking forward to seeing what this new solution can do.
