Article
Engineering, Aerospace
Dai Jian, Zuo Qiuru, Huang Chao
Summary: The study found that the grooved configuration significantly improves supersonic mixing in the scramjet combustor, enhancing fuel uniformity in the downstream region.
Article
Chemistry, Physical
Chaolong Li, Likun Ma, Zhixun Xia, Binbin Chen, Yunchao Feng, Yifan Duan
Summary: This paper investigates the mixing process of a fuel jet in a supersonic crossflow using orthogonal analysis. The study considers the influences of various parameters on the mixing process and proposes two new dimensionless numbers, BS and LJ. The results show that several parameters have a significant impact on the penetration depth and total pressure recovery, and the dimensionless numbers have a positive correlation with mixing efficiency. The findings provide guidance for the optimization design of supersonic combustors.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Aerospace
Jian Dai, Chao Huang
Summary: The study discusses the effects of the secondary fuel jet on flow field structure and mixing enhancement performance by changing the angle and spacing of multiple rows of jet holes. It is found that different angles of the fuel jet affect penetration depth and mixing performance differently. The spacing of jet holes also influences the mixing coefficient fluctuation.
Article
Engineering, Aerospace
Gautam Choubey, Pabbala Monish Yadav, Yuvarajan Devarajan, Wei Huang
Summary: The research results indicate that the flame holding capacity of a hydrogen-fuelled supersonic combustor is better than an ethylene-fuelled combustor. The introduction of a shock generator can enhance the mixing of fuel with supersonic airflow.
Article
Instruments & Instrumentation
Alexander A. Ryabin, Dmitry Pelegov
Summary: This study investigates the application of micro-Raman spectroscopy in powder samples with irregular shapes and sizes close to the wavelength of the probing laser. The results show that the vertical resolution should be described qualitatively rather than quantitatively for such samples. Additionally, Raman probing can be used for both multilayer and superficial analysis.
APPLIED SPECTROSCOPY
(2022)
Article
Chemistry, Physical
Z. Li, Gautam Choubey, Hosam A. Saad, Awad Musa, Yuelei Zhang, Chenggang Hu
Summary: This article investigates the impact of fuel injection systems in the combustion chamber on the overall thrust efficiency of high-speed vehicles. It reveals that the 3-lobe nozzle is more efficient than other styles and the circular jet has a higher mixing productivity compared to other cases.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Physics, Multidisciplinary
Liu Jun, Wang Pei, Sun Zhi-Yuan, Zhang Feng-Guo, He An-Min
Summary: This paper theoretically analyzes the phenomenon of gas penetrating the metal micro spallation zone, and provides calculation formulas for the maximum penetration depth, sealing time, and maximum mass of the gas. The analysis is conducted under quasi-static and semi-dynamic conditions to determine the upper and lower limits of gas penetration. The study emphasizes the need for further in-depth research based on experimental and simulation confirmation.
ACTA PHYSICA SINICA
(2021)
Article
Pharmacology & Pharmacy
Kiyoon Kwon, Youngmin Hwang, Junyoung Jung, Giyoong Tae
Summary: Mixing with adenosine tetraphosphate (ATP) greatly enhances the transport and permeation of a polymeric nanocarrier across the retina via intravitreal administration, showing potential for a new method of drug delivery to the retina.
Article
Energy & Fuels
Zhifei Zhang, Tie Li, Run Chen, Ning Wang, Yijie Wei, Dawei Wu
Summary: The study investigates the direct injection of gaseous ammonia as a fuel for engines, focusing on injection characteristics, fuel-air mixing processes, and the influence of pressure on ammonia jet development. Results show that ammonia jets have similar tip penetrations and jet angles to methane jets, but significantly lower equivalence ratios.
Article
Engineering, Aerospace
Dai Jian, Huang Chao, Zuo Qiuru, Xu Fei
Summary: This study investigates the effects of different supersonic airflow conditions on the flow field by using simulations. The results show that the shear layer gradually slopes downward with increasing Mach number, and the bow shock induced by the jet develops and cuts off the shear layer vortex. Moreover, an increase in total pressure of the airflow leads to a sharp increase in penetration depth and mixing efficiency.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Construction & Building Technology
Rui Zhong, Fengling Zhang
Summary: This experimental study evaluated the effectiveness of passive and active strategies in improving the projectile impact resistance of cementitious matrices. The results showed that modifying the bond structure and aggravating projectile damage can significantly reduce penetration depth and crack formation.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Engineering, Biomedical
Yang Zhu, Can Kang, Wei Cai, Chao Huang
Summary: The present study aims to investigate the operational characteristics of the needle-free injector and the effects of operating parameters on injection performance. The results show that the peak stagnation pressure increases with driving pressure, and the injection process consists of two distinct stages - penetration and dispersion. The nozzle diameter significantly affects the penetration ability.
MEDICAL ENGINEERING & PHYSICS
(2022)
Article
Optics
I. Gnilitskyi, W. Alnusirat, M. Sorgato, L. Orazi, G. Lucchetta
Summary: In this study, the influence of two different types of laser-induced periodic surface structures on the flow length in micro injection molding was evaluated. The performance of an untreated cavity surface was compared with surfaces modified by LIPSS. The phenomenon was investigated by localizing the weld lines created by the polymer flow in different surface treatments.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Automation & Control Systems
Julio Coroado, Supriyo Ganguly, Wojciech Suder, Stewart Williams, Sonia Meco, Goncalo Pardal
Summary: The digital control of the latest nanosecond pulsed wave fibre lasers enables high precision and flexibility in energy application during welding processes, leading to reduced heat input and improved welding quality. By studying parameters like peak power, pulse energy, and width, different pulse shapes and spatial profiles can be chosen to achieve specific welding depths independent of beam diameter. Research also shows that maintaining a constant balance between pulse power factor and interaction time allows for obtaining identical penetration depth but varied weld metal profiles with different system parameters.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Rachel Honnert, Valery Masson, Christine Lac, Tim Nagel
Summary: A new mixing length adapted to the constraints of the hectometric-scale gray zone of turbulence for neutral and convective boundary layers is proposed, combining lengths from mesoscale simulations and Large-Eddy Simulations. This method allows for the right proportion between subgrid and resolved turbulent exchanges in Large Eddy Simulations, opening up the possibility of using a single mixing length regardless of the atmospheric model's grid mesh or boundary layer depth.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)