Articles tagged with "heat-transfer"
Frontier supercomputer uncovers why worn turbine blades drain jet fuel
Researchers from the University of Melbourne, GE Aerospace, and Oak Ridge National Laboratory utilized the Frontier supercomputer—the world’s first exascale system for open science—to investigate how microscopic surface damage on high-pressure turbine (HPT) blades affects jet engine performance. Operating under extreme temperatures exceeding 3,600°F (2,000°C), turbine blades develop surface roughness from erosion, oxidation, and wear, which increases aerodynamic losses and heat transfer. This degradation reduces fuel efficiency, durability, and necessitates more frequent maintenance. The team conducted unprecedentedly detailed simulations with 10–20 billion grid points, revealing that traditional models of roughness effects based on simple geometries do not accurately capture the complex fluid dynamics in turbine blades. The study found that surface roughness accelerates the transition from laminar to turbulent flow on turbine blades, significantly increasing heat transfer and aerodynamic losses. These effects lead to reduced engine efficiency and shorter component lifespans, thereby increasing fuel consumption and maintenance needs. The researchers employed direct
energyturbine-bladesjet-engine-efficiencysupercomputer-simulationmaterials-degradationaerodynamicsheat-transferLiquid-based cooling beats limits of solid-state refrigeration
Researchers at the Chinese Academy of Sciences, led by Prof. Li Bing, have developed a novel refrigeration method based on the dissolution barocaloric effect that promises zero carbon emissions and improved cooling efficiency. Traditional refrigeration systems, which rely on vapor-compression, contribute significantly to global carbon emissions, while solid-state cooling—though environmentally friendlier—has been limited by poor heat transfer. The new approach overcomes this by integrating solid cooling effects with liquid flow, using the salt ammonium thiocyanate dissolved in water. Applying pressure causes the salt to precipitate, enabling a reversible cycle that produces continuous cooling with efficient heat transfer, combining refrigerant and heat-transfer medium in a single flowing liquid. Laboratory tests demonstrated remarkable performance, with temperature drops of nearly 30 kelvins in 20 seconds at room temperature and up to 54 kelvins at higher temperatures, surpassing existing solid-state barocaloric materials. Simulations indicated a cooling capacity of 67 joules per gram and an efficiency
energyrefrigerationcooling-technologybarocaloric-materialscarbon-emissions-reductionheat-transfersustainable-coolingMOCHI Blocks 90% Of Heat Transfer In Windows - CleanTechnica
Researchers at the University of Colorado Boulder have developed a new window coating called MOCHI (Mesoporous Optically Clear Heat Insulator) that significantly reduces heat transfer while maintaining transparency. This innovative material is a 5-millimeter-thick silicone gel embedded with millions of tiny air bubbles, allowing 99% of visible light to pass through but blocking 90% of heat transfer. MOCHI can be applied as thin sheets to existing windows, potentially reducing the energy demand for heating and cooling buildings, which currently accounts for about 40% of global energy use. The coating is durable, lasting up to 20 years, and aims to improve indoor comfort without increasing energy consumption. MOCHI differs from traditional insulating materials like aerogels by its highly controlled microscopic air pockets. Unlike aerogels, which scatter light and appear cloudy due to randomly distributed air bubbles, MOCHI’s air pockets are uniformly structured, resulting in near-complete transparency. The researchers achieved this by using surfactant molecules to
energymaterialsinsulationheat-transferMOCHItransparent-materialsenergy-efficiencyUS seeks inspiration from nature for next-gen nuclear fuel design
Scientists at Idaho National Laboratory (INL) are pioneering a novel approach to nuclear fuel design by drawing inspiration from nature’s mathematics, specifically triply periodic minimal surfaces (TPMS). These complex, repeating lattice structures, found naturally in butterfly wings and sea urchin shells, offer highly efficient geometries that can enhance heat transfer in nuclear fuel. INL’s concept, called the Intertwined Nuclear Fuel Lattice for Uprated heat eXchange (INFLUX), replaces traditional solid cylindrical fuel rods with a TPMS-based lattice. This design increases surface area contact with coolant, enabling more efficient heat removal and potentially leading to safer, more compact, and higher-performing nuclear reactors. Recent laboratory tests involving 3D-printed electrically conductive models of the INFLUX lattice demonstrated that the TPMS geometry transfers heat about three times more efficiently than conventional fuel rods. This improvement could allow for thinner fuel, lower operating temperatures, and reduced thermal stress, enhancing reactor performance and economics. Manufacturing challenges remain due
energynuclear-fueladditive-manufacturingheat-transfertriply-periodic-minimal-surfacesreactor-technologymaterials-scienceMIT's Asegun Henry is designing energy systems to outlast fossil fuels
Asegun Henry, a mechanical engineering professor at MIT and head of the Atomistic Simulation & Energy (ASE) Research Group, is focused on designing energy systems that can decarbonize the planet without compromising reliability. His career has spanned roles at Georgia Tech, Oak Ridge National Lab, Northwestern, and the Department of Energy’s ARPA-E, where he contributed to groundbreaking research including a liquid metal pump operating above 1,473 kelvins—earning a Guinness World Record—and a thermophotovoltaic cell achieving over 40% efficiency, recognized as a top breakthrough by Physics World in 2022. Henry’s work bridges atomic-level heat transport simulations and large-scale engineering innovations aimed at advancing clean energy technologies. Henry’s interest in mechanical engineering evolved from an initial focus on civil engineering, inspired by his early research on building vibrations during earthquakes and a curiosity about the nature of temperature and heat transfer. His academic journey was profoundly shaped by mentorship from MIT’s Gang Chen and experiences across several
energyclean-energythermophotovoltaicheat-transferdecarbonizationrenewable-energyenergy-systemsScientists discover boron arsenide beats diamond in heat transfer
Researchers at the University of Houston have discovered that boron arsenide (BAs), a synthetic crystal, surpasses diamond in thermal conductivity, achieving values above 2,100 W/mK at room temperature. This finding challenges the long-held belief that diamond is the best isotropic heat conductor and suggests that existing theoretical models need revision, as previous calculations—factoring in four-phonon scattering—had capped BAs’s conductivity at 1,360 W/mK. The breakthrough was made possible by producing ultra-pure BAs crystals through refined synthesis techniques, overcoming limitations caused by impurities in earlier samples. Beyond its record-breaking heat conduction, boron arsenide also exhibits promising semiconductor properties, including a wider band gap, higher carrier mobility, and compatibility with chip integration due to its thermal expansion coefficient. These combined attributes make BAs a strong candidate to outperform silicon in electronics, offering potential improvements in thermal management for devices ranging from smartphones to data centers and high-performance computing systems. Supported by a National
materialsboron-arsenidethermal-conductivitysemiconductor-materialsheat-transferelectronics-coolingadvanced-materialsPhysicists see heat move as a wave after 90 years of theory
Physicists at MIT have, for the first time, directly observed and filmed the quantum phenomenon known as "second sound," a theory predicted in 1938 but never before visually confirmed. Unlike normal heat diffusion, second sound occurs in superfluid states where heat propagates as a wave, similar to sound, with the surrounding fluid remaining stationary. The team overcame significant experimental challenges by cooling gases to near absolute zero and using lithium-6 atoms, whose resonance frequency shifts with temperature, allowing them to track heat movement via radio wave-induced resonance. This breakthrough enabled real-time visualization of heat waves in a superfluid, marking a major advance in studying quantum states of matter. The ability to observe second sound has important scientific and technological implications. It offers new insights into extreme states of matter such as those found in neutron stars, potentially improving astrophysical models. On Earth, the findings could advance research into high-temperature superconductors, which are crucial for energy-efficient technologies like lossless power transmission and magnetic levitation.
energyquantum-physicssuperfluidityheat-transfersuperconductivitythermal-imagingMIT-researchAre Those Viral ‘Cooling Blankets’ for Real?
The article examines the popular concept of "cooling blankets" circulating on social media, clarifying that most marketed products do not truly cool the body. While these blankets may be more breathable and less heat-retentive than traditional blankets, they do not actively lower body temperature; in fact, simply having no blanket is generally cooler. The article explains the physics behind temperature and heat transfer, emphasizing that heat flows from warmer to cooler objects until equilibrium is reached, and that "coolness" cannot be transferred. Blankets function primarily as insulators, slowing heat exchange between the body and the environment. When a person is hot and uses a blanket, it usually traps heat and makes them feel warmer unless the surrounding air is hotter than body temperature. However, a blanket initially cooler than the body can absorb some thermal energy, providing a brief cooling effect until temperatures equalize. The article suggests that an effective cooling blanket would need a high mass and specific heat capacity to absorb more body heat and maintain a cooler temperature
energythermal-energyheat-transferspecific-heat-capacityinsulationcooling-technologymaterials-science