The production process of biofuels from plant-based materials poses significant economic barriers to widespread use. Despite the benefits of biofuels being renewable, clean-burning, and carbon-neutral, their availability is limited, particularly for vehicle use. As of 2014, only 2% of retail fueling stations in the U.S. offered ethanol-based fuel E85. The National Renewable Energy Laboratory (NREL) aims to overcome these barriers by gaining a better understanding of the physical processes behind biofuel conversion. Supported by the Computational Pyrolysis Consortium, NREL is developing computational models that accurately represent biomass particle geometry to improve reactor design and operation for mass production of biofuel.

Designing an electrohydraulic power steering (EHPS) system involves managing numerous interrelated components, where minor adjustments can significantly impact the system's function, efficiency, and reliability. The complexity of the system, which includes an electronic control unit (ECU), torque sensor, valve, and pipe system, requires a detailed understanding of how each part interacts. Traditional validation and physical testing methods are expensive and time-consuming, often taking up to six months. This slow process is not conducive to the fast-paced design cycles required in the automotive industry. Therefore, there is a need for a more efficient method to refine and optimize EHPS designs before moving to physical testing.

The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) is undergoing a conversion from highly enriched uranium (HEU) to low-enriched uranium (LEU) fuel to meet the Global Threat Reduction Initiative's requirements. This conversion presents a complex challenge due to the unique fuel and core design of the HFIR, as well as its high power density. The primary challenge is to ensure that the new LEU fuel can maintain the reactor's performance, safety, and reliability. Researchers need to evaluate the impact of the fuel change on various aspects such as neutron scattering, isotope production, irradiation experiments, and neutron activation analyses. Additionally, the HFIR will need to operate at a higher power level (100 MW) to maintain the same neutron flux, which increases the demands on the reactor's thermal margin and safety.

Engineers face daily technical challenges in hearing aid design, with feedback being a major issue that leads to high-pitched squealing or whistling, limiting the amount of gain the aid can provide. Feedback usually occurs when a hearing aid’s microphone picks up sound or vibration inadvertently diverted from what’s being channeled into the ear canal and sends it back through the amplifier, creating undesirable oscillations. The challenge is to design hearing aids that are compact and unobtrusive, yet still capable of providing a powerful sound output to overcome the user’s hearing loss. This makes solving the feedback issue more challenging, as engineers must cram all the hardware components into the smallest space possible without causing feedback instability.

Metamaterials, which are artificially structured materials, have the potential to revolutionize various fields by manipulating electromagnetic waves. However, the challenge lies in the high level of control required over their structure and the high ohmic loss due to the metal components. These materials derive their unique properties from their structure rather than their chemical composition, making the design and fabrication of complex structures a significant challenge. Additionally, precise knowledge of the response at each frequency of interest is needed, making accurate frequency-domain simulations a requirement. The high ohmic loss causes electromagnetic waves to be strongly attenuated, posing another challenge in the practical application of metamaterials.

Deep space and the human body present unique challenges for designing devices that can operate safely, reliably, and efficiently. Equipment used in extreme environments such as aqueous conditions, severe temperatures, and high pressure levels often struggle with stable and efficient power generation. The search for better power efficiency in devices like deep-space satellites and medical equipment has identified electron emission as a potential method for power generation. Electron emission occurs when a metal surface or electrode is subjected to an electrostatic field, heat, or incoming light, causing electrons to escape the metal and be collected for usable electricity. The Italian Institute of Technology (IIT) and the European Space Agency (ESA) are collaborating to develop systems based on electron emission for solar power collection on deep-space satellites. Researchers at IIT are also applying similar concepts to power nanoantennas for studying electrical signals in the brain.

The built environment, encompassing everything from large metropolitan areas to individual buildings, is continually impacted by physics-based processes such as heat transfer, air flow, and moisture transport. These processes can affect energy efficiency, health and safety, operating costs, durability, and historic preservation. Jos van Schijndel, founder of CompuToolAble and assistant professor at Eindhoven University of Technology, faces the challenge of making complex modeling and simulation concepts accessible to clients and students. His goal is to improve the built environment and preserve historic structures and artifacts through accurate modeling and simulation.

HARMAN, a market leader in connected car setups, faces the challenge of designing unique audio configurations for each vehicle model. The process involves accounting for various components and car acoustics, such as speaker placement, orientation, and packaging. Traditional methods of physical testing and in situ listening are time-consuming and costly. The need for a quicker, more efficient development process that can keep up with the rapid pace of vehicle design is paramount. Engineers at HARMAN sought a solution that would allow them to virtually 'tune' their audio systems before creating live prototypes, thereby saving time and resources.

The primary challenge faced by the MIT Plasma Science and Fusion Center (PSFC) researchers was to design a compact nuclear fusion machine, the Advanced Divertor eXperiment (ADX), capable of sustaining reactor-level heat fluxes and magnetic fields. The ADX needed to simulate the conditions of a full-scale fusion reactor while being a research and development testbed. The design had to withstand high temperatures, magnetic fields, and plasma disruptions, which are significant sources of stress. Plasma disruptions, particularly vertical displacement events (VDE), pose a severe threat as they generate large eddy currents and Lorentz forces that can cause substantial stress and displacement in the vacuum vessel. The researchers needed to ensure that the ADX could survive these conditions without structural failure.

Anyone who has slept near an airport will know the sensation — an early morning flight wakes you from sleep, not only because the engine is noisy but also because everything around you seems to be shaking. Likewise, people living near wind turbines, military sites, or hospitals with helicopter landing pads often complain that windows rattle and everyday objects buzz when there is external noise. More puzzling for them is the fact that even when they can discern no sound, they may still notice irritating vibrations. If the response of the sound is 20 vibrations per second (20 Hz) or less, it is described as infrasound, meaning that the original sound is not usually audible to the human ear. The effects, however, are very easy to detect. As waves hit windows, spread to the floor, and affect internal walls, they induce a noticeable indoor vibration. Low-frequency sound waves are notorious for their potential to create annoying disturbances. Noise is part of modern life and there are formal standards that use sound pressure level measurements to recognize high-frequency sound waves at levels of sensitivity, intrusion, and danger for humans. According to Finn Løvholt of the Norwegian Geotechnical Institute (NGI), the generation of building vibration due to infrasound is an area of research that has not been explored extensively. For this reason, NGI, an international center for research and consulting within the geosciences, has been running investigative programs for several years on behalf of the Norwegian Defence Estate Agency.

Routine natural gas maintenance often requires digging into main roads, causing significant disruptions. GTI aimed to investigate the industry standards for squeeze-off length in gas pipelines to make the process more efficient and less invasive. The current ASTM standard requires a squeeze-off distance of either three pipe diameters or twelve inches from the next pipe fitting, whichever is greater. This large length requirement leads to more digging, rerouted roads, and increased time and costs. GTI researchers sought to determine if the twelve-inch distance is necessary for smaller pipes, aiming to reduce the minimum required distance without exceeding industry-accepted levels of strain and stress concentration.

Graphene, a single-atom-thick film of graphite, has shown immense potential in various applications since its discovery in 2004. While its electrical and thermal conductivity made it attractive for electronics, its optoelectronic capabilities were initially overlooked. However, it soon became clear that graphene could serve as a transparent conducting electrode, offering comparable or better performance than indium tin oxide (ITO). Despite its potential, fabricating high-quality, large-area graphene films remains a challenge. This has hindered the practical application of graphene in optoelectronics and photonics, particularly in the field of plasmonics, which deals with the efficient excitation, control, and use of plasmons. The diffraction limit of light poses a fundamental challenge in photonics, but plasmonics helps address this by enabling light confinement at the nanoscale. Researchers at Purdue University, led by Alexander V. Kildishev, are leveraging simulation tools to overcome these challenges and bring graphene closer to practical applications.

The primary challenge faced by FUJIFILM Dimatix was to design unimorph diaphragm actuators for their newest ink deposition products. These actuators needed to be miniaturized to reduce costs while maximizing deflection and matching the actuator's impedance to the flow channels and nozzle. The goal was to generate a droplet meeting a target mass at a given velocity with a target maximum firing frequency for the available voltage. The complexity of the design required a deep understanding of the interactions between the piezoelectric materials and the surrounding components, necessitating a robust simulation approach to optimize the design parameters.

Physicians rate predictability as their number one concern with ablation performance. The higher the level of predictability, the easier it is for a physician to plan a treatment procedure that will be safer, more effective, and less time-consuming. RF ablation procedures face challenges due to varying electrical conductivities of tissues and the rapid decrease in electrical conductivity as tissue temperature approaches 100°C. This makes it difficult to generate temperatures high enough to cause cell breakdown. MW ablation technology attempts to overcome these limitations by using an EM field radiated into the tissue. However, tissue type and vaporization of water during ablation cause the size and shape of the EM field to vary, affecting predictability.

Companies developing new and improved power transformer equipment incur costs for prototyping and testing as they work to reduce transformer hum. At ABB, a team of engineers develops multiphysics simulations and custom-built applications to offer insight into their designs. Transformer noise often comes from several sources, such as vibrations in the transformer core or auxiliary fans and pumps used in the cooling system. Each of these sources needs to be addressed differently to reduce noise. ABB’s transformers comprise a metal core with coils of wire wound around different sections, an enclosure or tank to protect these components, and an insulating oil inside the tank. Passing alternating current through the windings of one coil creates a magnetic flux that induces current in an adjacent coil. The voltage adjustment is achieved through different numbers of coil turns. Because the core is made of steel, a magnetostrictive material, these magnetic fluxes — which alternate direction — cause mechanical strains. This generates vibrations from the quick growing and shrinking of the metal. These vibrations travel to the tank walls through the oil and the clamping points that hold the inner core in place, creating an audible hum known as core noise. In addition to the core noise, the alternating current in the coil produces Lorentz forces in the individual windings, causing vibrations known as load noise that add to the mechanical energy transferred to the tank.

The multiphysics nature of plasmas presents enormous challenges for numerical simulations; analysis of the CCP process presents added difficulty due to the existence of a plasma sheath, the dynamic behavior of the plasma, and the large number of RF cycles required to reach a periodic steady state. Power deposition into the plasma is highly non-linear and the strong gradient of the electric field in the plasma sheath may lead to numerical instabilities unless a sufficiently fine mesh is applied. Typical CCP reactors may also contain sharp geometric corners that can cause a substantial local electric field that provide unphysical ion fluxes.

The furniture industry requires rigorous testing to ensure products meet safety and quality standards. This process is costly and time-consuming, often resulting in significant expenses for manufacturers when designs fail. An independent test house aimed to reduce this burden by providing a virtual testing tool to predict whether chair designs would pass or fail before physical testing.

Other options for wireless energy transfer require precise device positioning on a pad or holder, very close proximity to the charging source, and the source can only charge a single device with a single coil. WiTricity engineers aimed to overcome these limitations by leveraging magnetic resonance to enable more flexible and efficient wireless power transfer. They needed to design a system that could charge multiple devices simultaneously, over distances, and through various materials, while maintaining high efficiency and low power losses. Additionally, they faced the challenge of making the technology scalable for a wide range of devices, from smartphones to electric vehicles, and ensuring that the system met safety regulations for electromagnetic fields.

Ensuring the consistency and quality of chocolate bars, wafers, and cereals is a significant challenge for Nestlé. For chocolate bars, the flow rate and pressure of the chocolate exiting each nozzle must be consistent to ensure uniform weight and nutritional content. For wafers, uneven heating during baking can cause different moisture concentrations, affecting texture and potentially causing spontaneous snapping. For cereals, the high-temperature extruder must maintain consistent pressure and friction to cook the dough evenly, and the viscometer housing must withstand high pressure to ensure consistent dough quality.

The semiconductor industry relies heavily on silicon wafers, which are also crucial for photovoltaic (PV) applications. However, the cost per unit of power generated by solar cells needs to be reduced to make solar energy competitive with fossil fuels. EMIX's challenge was to optimize their continuous cold crucible casting (4C) process to produce high-purity silicon efficiently. This process involves numerous variables, including cooling methods, pull rates, and electromagnetic fields, which need to be optimized to improve production efficiency and reduce costs.

Given the long development cycle for vehicles, automobile manufacturers must plan their upcoming lines far in advance. With growing emission regulations and the rising cost of gas, full electric and hybrid vehicles are becoming more attractive and growing in market share. At the Fiat Research Center in Orbassano, the focus is on developing electric and hybrid vehicles using lithium and lead-acid batteries as well as supercapacitors. Fiat currently has several light trucks that run on electric drives, and the next application will be an electric version of the Fiat 500, which has been announced for the US market. The challenge lies in combining as many as 100 lithium-ion battery pouch cells into battery packs that generate the 350V needed while providing sufficient cooling and keeping the packs as small and light as possible. The maximum temperature differential among all the cells in a pack must not exceed 5 °C. If the temperature of the pack is too low, it limits the charge you can extract; if it is too high, it risks thermal runaway, leading to electrolyte emission, smoke, or fire.

Anisotropic materials behave differently depending on the direction they are loaded, but current methods of material production offer limited control over anisotropy. This limitation makes it difficult to exploit the advantages of anisotropic materials for product design. Researchers at TNO aimed to develop a procedure for designing manufacturable anisotropic structures using stiffness and topology optimization techniques. They sought to create materials with specific properties, such as twice the stiffness in one planar direction compared to another, and to extend these capabilities to multimaterial structures. The challenge was to optimize the local distribution and orientation of materials at the microlevel and then scale these optimizations to larger devices while maintaining feasible computation times.

One of the challenges of shaped metal deposition (SMD) is that thermal expansion of the molten metal can deform the cladding as it cools, resulting in a final product that is different than what was anticipated. To predict the outcome of a proposed design, it is necessary to either minimize the deformations or alter the design to account for them. This requires solving a time-dependent coupled thermomechanical analysis that predicts residual thermal stresses and deformation, which arise from SMD thermal cycles.

In extreme climates, moisture and temperature changes can damage building foundations. Vahanen Group, a company specializing in building services, analyzes the potential for frost damage in buildings being considered for renovation. Their work is especially vital in cases where renovations are necessary due to existing damage, such as when heating systems and pipes need to be replaced. The challenge is to determine whether certain renovations to foundations or heating systems would require adding external frost insulation, which, if added unnecessarily, would waste valuable money, time, and work.

Food companies face the challenge of achieving the right moisture and texture in puffed snacks to ensure customer satisfaction. The process of puffing rice involves complex physics, including mass, momentum, and energy transport, rapid water evaporation, material phase transition, pressure buildup, and plastic deformation. Companies need to optimize processing conditions to ensure consistent texture, flavor, moisture content, and food safety. The research team at Cornell University, led by Prof. Ashim Datta, aimed to model the dynamics and material behavior during the puffing of parboiled rice to address these challenges.

The performance and durability of lithium-ion (Li-ion) batteries are heavily influenced by their operating temperature. Their performance decreases at low temperatures while the battery degrades quickly at high temperatures. This means that overall reliability is compromised, creating a potential safety issue. Industry research has led to standards regulating the ability of a battery to withstand fluctuations in temperature when it is in operation. In contrast, there has been much less focus on the temperatures that batteries are exposed to during the manufacturing process, which includes plasma pretreatment, UV curing, laser welding, ultrasonic joining, hot stacking, and hot gluing. A Li-ion battery may contain thousands of individual cells, which have to be stacked together. This is typically done through an assembling procedure that may involve various heat treatments, some of which can be extremely intense and expose the casing or other parts to high temperatures for short times. Gerd Liebig of NEXT ENERGY EWE Research Centre for Energy Technology at the University of Oldenburg, Germany, explained, “It is already well known that certain processes such as welding greatly increase the temperature within a battery. What is not known is the extent to which such elevated temperatures could propagate within and compromise a cell.”

OLEDs, despite their advantages, suffer from significant light loss and energy inefficiency. Researchers at Konica Minolta are working to address these issues by understanding and mitigating the complex plasmon coupling phenomenon, which accounts for 40% of the light lost in OLEDs. This phenomenon involves the interaction of light with surface plasmons at the interface between the cathode and the organic material, leading to energy dissipation as heat. The challenge is to find ways to reduce these losses and improve the overall efficiency and brightness of OLEDs.

Simulation consultants are using custom applications as an effective way to communicate their work to clients. Instead of delivering a static report, they can now deploy a product that contains the intricacy of an unabridged mathematical model, with the clarity and usability of an app. This lets clients run their simulations independently. At BE CAE & Test, we have created such an app to simulate a surface-mount device (SMD). Whether devices use or convert energy, they must properly manage heat so that they continue to operate in a designated temperature range. An SMD is an example of one electronic system that clients ask us to model. We make use of COMSOL Multiphysics® software to investigate these systems due to the wide range of physics that can be taken into account and the ease with which one can couple them.

Oil spills are urgent and unexpected events that cause significant damage to aquatic environments and marine life. Current methods for containing and recovering spilled oil, such as booms and skimmers, are often costly and only partially effective. These methods need to be deployed quickly to be effective, and even then, they often fail to recover most of the oil, which can sink to the sea floor. The collected oil-water mixture is often only partially usable, leading to further environmental concerns and wasted oil.

The development of a device meant to assist or completely replace the functioning of the heart is undeniably complex. This design process involves immense challenges, from supplying power to the device to ensuring it does not interfere with normal biological functioning. Researchers at St. Jude Medical use multiphysics simulation to engineer LVADs, Left Ventricular Assist Devices, in an ongoing effort to improve the outlook and quality of life of patients with heart failure. The condition typically begins with the left side of the heart, as the left ventricle is responsible for pumping oxygen-rich blood throughout the body, a greater distance than the right ventricle, which pumps blood through the lungs. Often, in patients with a poorly functioning left ventricle, an LVAD can provide mechanical circulatory support. The ventricle assist device is one of the most complex machines ever implanted in a human being. An LVAD must circulate the entire human blood stream and support life, as well as be compatible with the internal environment of the human body. Thoratec, now part of St. Jude Medical, brought LVADs to a wide market in 2010, after years of clinical trials.