Article
Energy & Fuels
Ariff Magdoom Mahuthannan, Yedhu Krishna, Gaetano Magnotti, William L. Roberts, Deanna A. Lacoste
Summary: This study conducted time resolved thermometry of flame quenching events in a specific geometry to mimic a flame arrester, using high-speed filtered Rayleigh scattering and dynamic pressure measurements. The results showed that systematic quenching occurred when the flame temperature dropped below 1600K, and the integral of the temperature profile across the flame front could predict quenching events. Heat transfer analysis provided explanations for these findings.
Review
Chemistry, Physical
Christophe Lucchesi, Rodolphe Vaillon, Pierre-Olivier Chapuis
Summary: Energy transport theories are revisited at the nanoscale, with significant increase in radiative heat transfer observed in recent years. Nanotechnology has allowed for experimental verifications and advancements in this field, while challenges remain in applying single-wavelength approaches to broadband thermal emitters. The potential of thermal nanophotonics is promising, with molecular and chemical viewpoints yet to be fully addressed.
NANOSCALE HORIZONS
(2021)
Article
Engineering, Chemical
M. Sajedi, A. Safavinejad, M. Atashafrooz
Summary: This paper investigates the entropy generation in combined convection-radiation heat transfer between two parallel isothermal plates filled with a homogeneous and uniform porous medium. The study considers the contributions of fluid friction, conductive heat transfer, and radiative heat transfer to the entropy generation. Different boundary conditions and parameters are examined to analyze their effects on total entropy generation. The results demonstrate the significant impact of radiative heat transfer on entropy generation rates and reveal higher entropy generation numbers for cold walls compared to hot walls.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Nanoscience & Nanotechnology
Pei Zeng, Zhiwen Shu, Shi Zhang, Huikang Liang, Yuting Zhou, Dedong Ba, Zhanzu Feng, Mengjie Zheng, Jianhui Wu, Yiqin Chen, Huigao Duan
Summary: This study successfully demonstrates an effective approach for forming ultrasmall metallic nanogaps based on the spontaneous nanoscale dewetting effect during metal deposition. By adjusting the initial opening size of the exposed resist template, tiny metallic nanogaps can be obtained. The method is effective for fabricating sub-10 nm silver nanostructure gaps and even sub-5 nm metallic gaps.
Article
Thermodynamics
Alexandre Coulombe, Mouna Rahal, Hachimi Fellouah, Sebastien Poncet
Summary: In this study, a 1D frost formation model is improved and validated using experimental data. It is found that larger plate spacing is less affected by frost growth, and the heat recovery efficiency decreases from 87% to 77% for a 2.5 mm spacing after 25 minutes.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Ulrich Hohenester, Gerhard Unger
Summary: In this paper, the authors introduced a theoretical framework for nanoscale electromagnetism based on Feibelman parameters and demonstrated how to implement mesoscopic boundary conditions in a boundary element method approach. The simulation results showed perfect agreement with Mie theory.
Article
Physics, Fluids & Plasmas
Alexandros Tsimpoukis, Steryios Naris, Dimitris Valougeorgis
Summary: This study computationally investigates the flow of pressure-driven binary gas mixtures between parallel plates in a wide range of gas rarefaction and oscillation frequency, finding that heavier species are more drastically affected and that the flow rate amplitudes of species tend to the inverse of their molecular mass ratio at very high frequencies. The mixture flow rate amplitude is larger than single gas, and both the amplitude and phase angle vary nonmonotonically with the molar fraction.
Article
Mechanics
R. Ayats, F. Marques, A. Meseguer, P. D. Weidman
Summary: The study investigates Navier-Stokes equilibrium solutions of a viscous fluid confined between two infinite parallel plates, revealing the existence of both two-dimensional and three-dimensional solutions, as well as the disappearance, creation, and annihilation of solutions at different stretching or shrinking rates. Additionally, new families of equilibria are observed near cuspidal codimension-2 bifurcation points when both plates are simultaneously stretching or shrinking at higher rates, exhibiting behavior similar to other planar and cylindrical self-similar flows.
Article
Mechanics
Eric Bird, Zhi Liang
Summary: The aggregation of fine or ultrafine particles in liquid due to the nanobubble bridging capillary force is a critical process in many industrial applications. This study uses molecular dynamics simulations to verify the accuracy of a capillary force model in predicting the geometry and force of nanobubble bridges. The results show that the model gives good predictions for both concave and convex bridges.
Article
Thermodynamics
Ming-Qian Yuan, Yong Zhang, Shui-Hua Yang, Hong-Liang Yi
Summary: The study focuses on the near-field radiative heat transfer (NFRHT) between charged metallic plates under an external electric field, showing that copper plates have the largest NFRHT. The p-wave heat flux is greatly amplified by the perpendicular electric field, leading to rapid increase in heat flux between copper plates. The external electric field can be used to control NFRHT, which has various applications in thermal nano-devices.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Mubashar Arshad, Ali Hassan, Qusain Haider, Fahad M. Alharbi, Najah Alsubaie, Abdullah Alhushaybari, Diana-Petronela Burduhos-Nergis, Ahmed M. Galal
Summary: This research investigates the flow of two different hybrid nanofluids between two parallel plates placed at different heights. The study shows that oxide nanoparticles hybrid nanofluid performs better in heat transfer.
Article
Thermodynamics
Qingwen Dai, Sangqiu Chen, Wei Huang, Xiaolei Wang, Steffen Hardt
Summary: This work investigates the thermocapillary migration of liquid bridges and air bubbles between parallel plates, discussing factors such as thermal gradient, volume, and tilt angle. A critical tilt angle is found where migration is suspended, and a two-dimensional theoretical model is formulated to predict this angle. The application potential lies in tribological systems for replenishing liquid lubricant.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Multidisciplinary
Muhammad Danish Ikram, Muhammad Imran Asjad, Ali Akgul, Dumitru Baleanu
Summary: This paper discusses the fractional model of Brinkman type fluid (BTF) holding hybrid nanoparticles, solving the governing equations using Laplace transform method. The tested outcomes show that the constant proportional Caputo fractional operator (CPC) exhibits better memory effect than Caputo-Fabrizio fractional operator (CF).
ALEXANDRIA ENGINEERING JOURNAL
(2021)
Article
Thermodynamics
Chengshuai Su, Ceji Fu
Summary: In this study, near-field radiative heat transfer between two semi-infinite alpha-quartz plates was theoretically investigated using the fluctuation-dissipation theorem. By comparing with SiC and hBN cases and considering the influence of optic axis orientation, it was found that the near-field radiative heat flux between the two alpha-quartz plates can surpass that of SiC and hBN. This enhanced heat transfer is attributed to the excitation of phonon polaritons in alpha-quartz, particularly in the hyperbolic and double-negative-permittivity bands. The research also revealed that surface phonon polaritons in the double-negative-permittivity bands contribute more than half of the total near-field radiative heat flux for alpha-quartz.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Waqas Ashraf, Adnan
Summary: Investigation of nanofluids heat transport under hydrogen bonding is crucial for their applications in applied thermal and chemical engineering. Hybrid and ternary nanofluids with enhanced heat transport characteristics have been introduced to overcome the limitations of conventional fluids in engineering processes.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Chemistry, Multidisciplinary
Amin Reihani, Ju Won Lim, David K. Fork, Edgar Meyhofer, Pramod Reddy
Summary: The calorimetry of reactions involving nanomaterials is a current research focus, requiring high-resolution heat flow measurements and long-term thermal stability, especially at elevated reaction pressures and temperatures. An instrument for measuring the enthalpy of reactions between gas-phase reactants and milligram scale nanomaterial samples has been developed, with high calorimetric resolution and stability demonstrated through experiments involving H2 absorption on Pd nanoparticles. This study establishes the feasibility of performing high resolution calorimetry on milligram scale nanomaterials for future studies on catalysis, phase transformations, and thermochemical energy storage.
Article
Physics, Applied
Amin Reihani, Shen Yan, Yuxuan Luan, Rohith Mittapally, Edgar Meyhofer, Pramod Reddy
Summary: This study presents a custom-fabricated scanning thermal probe (STP) that can accurately measure the temperature of microdevices at elevated temperatures. By introducing a modulated heat input and analyzing the different components of the STP temperature, the tip-to-sample thermal resistance and microdevice surface temperature can be simultaneously deduced.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Shenzhen Xu, Bai Song
Summary: The study investigates the possibility of using surface-functionalized boron arsenide as a photocathode for solar-driven CO2 reduction, finding that Pyridine-functionalized BAs is a promising candidate due to its favorable catalytic activity and kinetics.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Multidisciplinary Sciences
Rohith Mittapally, Byungjun Lee, Linxiao Zhu, Amin Reihani, Ju Won Lim, Dejiu Fan, Stephen R. Forrest, Pramod Reddy, Edgar Meyhofer
Summary: This study demonstrates high-efficiency energy conversion in thermophotovoltaic devices at high power density by developing novel emitter devices and placing them in the near-field of photovoltaic cells, representing a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Amin Reihani, Yuxuan Luan, Shen Yan, Ju Won Lim, Edgar Meyhofer, Pramod Reddy
Summary: The quantitative mapping of temperature fields with nanometric resolution is crucial in various scientific research areas and emerging technologies. Recent advances in scanning thermal microscopy (SThM) have enabled simultaneous quantification of tip-sample thermal resistance and topography, allowing for quantitative thermometry even in situations where the temperature field is modulated. The introduction of a modulated heat input to the scanning thermal probe (STP) allows for the mapping of unmodulated temperature fields with high spatial and temperature resolution, facilitating temperature mapping of microdevices under practical operating conditions.
Article
Multidisciplinary Sciences
Zhiwei Ding, Ke Chen, Bai Song, Jungwoo Shin, Alexei A. Maznev, Keith A. Nelson, Gang Chen
Summary: In this study, the authors reported the direct observation of temperature wave (second sound) in graphite at a record-high temperature of over 200 K. They used experimental techniques and simulations to explain the role of thermal zero sound and the interplay among different groups of phonons.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Te-Huan Liu, Jiawei Zhou, Qian Xu, Xin Qian, Bai Song, Ronggui Yang
Summary: The study shows that long-range electron-phonon interaction can significantly suppress thermal conductivity in certain polar semiconductors by scattering acoustic phonons. The breaking of centrosymmetry has different effects on phonon transport in different crystal structures.
MATERIALS TODAY PHYSICS
(2022)
Editorial Material
Physics, Multidisciplinary
A. A. Maznev, Bai Song
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Qizhang Li, Qun Chen, Bai Song
Summary: This study achieves giant rectification ratios in thermal diodes by leveraging near field radiative thermal transport. Rational design of terminal materials and structural configurations enables excellent performance across different parameter ranges.
MATERIALS TODAY PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Fuwei Yang, Bai Song
Summary: Twisted bilayer graphene (TBLG) is a versatile platform for studying various transport phenomena. In this study, it is found that thermal flow is suppressed near the magic angle, with greater suppression at lower temperatures and larger gaps. When the chemical potential lies in the energy gap, over 100-fold heat-flow variation can be achieved within a small twist angle. By reducing the electron scattering rate, the radiation spectrum near the magic angle dramatically narrows, leading to over 10,000-fold suppression.
MATERIALS TODAY PHYSICS
(2022)
Article
Optics
Amin Reihani, Edgar Meyhofer, Pramod Reddy
Summary: Ultrahigh-resolution thermometry is crucial for various fields including bio-calorimetry, sensitive bolometry, and probing dissipation in electronic, optoelectronic, and quantum devices. However, achieving high-resolution measurements from microscale devices at room temperature remains challenging. This study presents a band-edge microthermometer based on the temperature-dependent optical properties of GaAs, enabling high-resolution measurements.
Article
Physics, Multidisciplinary
Laura Rincon-Garcia, Dakotah Thompson, Rohith Mittapally, Nicolas Agrait, Edgar Meyhofer, Pramod Reddy
Summary: This article investigates the near-field radiative heat transfer phenomenon between metallic surfaces and finds that the heat transfer rate can exceed the far-field rate by over a thousand times at small gaps. The authors also show that the heat transfer rate saturates due to the dominant contributions from transverse electric evanescent modes at small gaps.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Rohith Mittapally, Ju Won Lim, Lang Zhang, Owen D. Miller, Pramod Reddy, Edgar Meyhofer
Summary: Recent experiments have revealed that near-field radiative heat transfer (NFRHT) between objects separated by nanoscale gaps can significantly enhance heat transfer rates. Silicon dioxide (SiO2) surfaces, which support surface phonon polaritons (SPhP), demonstrate the most prominent enhancements. However, theoretical analysis suggests that SPhPs in SiO2 occur at frequencies much higher than optimal. In this study, we demonstrate theoretically that NFRHT mediated by SPhPs can be 5-fold larger for materials supporting SPhPs closer to the optimal frequency of 67 meV at room temperature. Furthermore, we experimentally show that MgF2 and Al2O3 closely approach this limit, with near-field thermal conductance between MgF2 plates separated by 50 nm reaching nearly 50% of the global SPhP bound. These findings lay the foundation for exploring the limits of radiative heat transfer rates at the nanoscale.
Article
Nanoscience & Nanotechnology
Ayan Majumder, Dakotah Thompson, Rohith Mittapally, Pramod Reddy, Edgar Meyhofer
Summary: Control of nanoscale thermal transport is crucial for various applications. Previous studies have suggested that enhanced heat transfer in planar membranes with nanoscale thickness is due to directional and spatially confined in-plane heat transfer. However, experimental evidence for this confinement is lacking. This study directly quantifies the spatial extent of heat transfer and provides detailed explanations for the observations, potentially leading to new approaches for active control of nanoscale heat flow.
Article
Nanoscience & Nanotechnology
Rohith Mittapally, Ju Won Lim, Edgar Meyhofer, Pramod Reddy, Bai Song
Summary: Recent measurements have shown that near-field radiative heat transfer (NFRHT) at the nanoscale is significantly different from far-field thermal radiation and can exceed the blackbody radiation limit by orders of magnitude. In this study, the thickness-dependence of NFRHT between planar nanofilms of magnesium fluoride was directly measured, demonstrating for the first time that nanofilms can enhance thermal radiation up to 800 times above the blackbody limit. Fluctuational electrodynamics calculations showed good agreement with the measured gap-size dependence, providing physical insight into the observed enhancement. These findings pave the way for exploring novel thin films in near-field thermal and energy systems.