Article
Thermodynamics
Makiko Ando, Atsushi Okamoto, Hiroki Nagai
Summary: This study investigates the effect of flow resistance of floating-type check valves on the heat transfer characteristics of an oscillating heat pipe with check valves (CVOHP). The results show that the thermal resistance of the CVOHP increases with the flow resistance of the check valves, while it does not significantly affect the startup characteristics. Additionally, the higher the heat input, the more the flow resistance of the check valves impacts the thermal resistance. It is necessary to control the flow resistance of the floating-type check valves at a low level for the high thermal performance of a CVOHP.
ASME JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Makiko Ando, Atsushi Okamoto, Hiroki Nagai
Summary: The study investigated the effects of check valve layout on the start-up and heat transfer characteristics of an Oscillating Heat Pipe with Check Valves (CVOHP), finding that locating all the check valves near the condenser or in an alternate arrangement can improve start-up characteristics, with no significant difference in steady-state thermal performance depending on the check valve layout. The optimal check valve layout could help achieve high start-up reliability and high steady-state thermal performance for the CVOHP.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Armando Di Meglio, Elio Di Giulio, Raffaele Dragonetti, Nicola Massarotti
Summary: This paper investigates the heat transfer between an oscillating compressible fluid and solid, considering the influence of finite thermal capacity. Through simulations on various simplified geometries of porous materials, a new physical interpretation is validated, and a complex dimensionless parameter is proposed to describe this phenomenon.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
C. Ozalp, D. B. Saydam, C. Polat, M. Soyler, E. Hurdogan
Summary: This study experimentally investigated the effect of a clockwise and counter-clockwise oscillating cylinder on the flow structure and heat transfer of a heated cylinder placed downstream. It was found that oscillating speed and amplitude can prevent boundary layer separation and improve heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2022)
Article
Thermodynamics
Guangyi Xie, Jilin Lei, Xiwen Deng, Dewen Jia, Wei Deng, Xiangsen Jiang, Jun Wen
Summary: The uneven temperature distribution of the piston is a significant cause of piston fatigue failure. This study investigates the effect of inclination angle on the flow and heat transfer characteristics of piston cooling galleries. It reveals that the inclination angle can influence the oil accumulation and circumferential heat transfer performance of the piston cooling galleries, resulting in adjustments to the average steady heat transfer coefficient.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Florian Schwarz, Shabhrish Reddy Uddehal, Alexander Lodermeyer, Eman Mohamadi Bagheri, Brigitte Forster-Heinlein, Stefan Becker
Summary: This study quantifies the thermal performance and flow behavior of oscillating heat pipes with a centrally located hot spot heater, revealing a strong interrelation between flow velocity values and resulting thermal resistance. The results show that higher flow velocity leads to lower thermal resistance, indicating a significant correlation between flow pattern and heat transfer in OHPs.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Ge-Yu Zhong, Peng-Fan Chen, Fa-Zhu Liu, Ying-Wen Liu
Summary: This study focuses on the unsteady characteristics of heat transfer process in wavy channels under oscillating flow, with findings on the factors influencing heat transfer performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Huaiji Bi, Jiayao Yang, Chunlin Chen, Baojun Luo
Summary: In this study, the heat transfer and flow characteristics of intermittent oscillating flow in a tube were numerically investigated. The results showed that compared to sinusoidal oscillating flow, the total heat transfer coefficient was 14.6% lower and the pressure drop was 0.83% higher in intermittent oscillating flow. The pressure drop curves were similar in both flows, and the velocity distributions were also comparable.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Environmental
Zhongyi Yan, Chengyan Lu, Junjie Zhuang, Tianming Chen, Huidong Zheng, Zuoyi Yan
Summary: In this study, the floating and heat transfer characteristics of catalyst particles in an oscillating flow reactor were investigated using experiments and mathematical models. The results showed a strong correlation between oscillatory force and solid volume fraction, as well as variations in heat transfer coefficient with oscillatory intensity and solid volume fraction. Overall, the research findings provide valuable data and theoretical support for the industrial application of oscillating flow reactors.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Mechanics
Wenzhe Hong, Yongsheng Wu, LiBiao Hu, Pengcheng Miao, Huajun Liu, Fang Liu, Yi Shi
Summary: Multi-phase flow hydrodynamics is crucial for modernizing engineering. This study comprehensively analyzes the flow state and heat transfer characteristics during the boiling process of liquid helium, with a focus on the retention of helium bubbles in high-field superconducting magnets. The analysis reveals the challenges faced by superconducting magnets operating at high magnetic fields and high temperatures.
Article
Engineering, Marine
Ussama Ali, M. D. Islam, Isam Janajreh
Summary: The impact of heat transfer and cylinder rotation on induced forces due to vortex shedding is numerically studied, and the results are presented in this work.
Article
Engineering, Chemical
Stefan Heidinger, Simon Unz, Michael Beckmann
Summary: The study investigates the heat and mass transfer to solid particles in one-dimensional oscillating flows. A meta-correlation for calculating the Nusselt number (Sherwood number) is derived by comparing 33 correlations and data point sets. These models are unified by their dependencies on the amplitude parameter 10(-3) <= epsilon <= 10(3) and the Reynolds number 10(-1) <= Re <= 10(6), and the epsilon-Re plane is used as a framework for graphical display.
Article
Thermodynamics
Jia-Jia Yu, Li Huang, Shouli Sun, Jin Yu, You-Rong Li
Summary: This paper presents a series of three-dimensional numerical simulations on the flow and heat transfer characteristics of RP-3 aviation kerosene in a horizontal tube under altered gravity levels at the supercritical pressure. The results show that the gravity level significantly affects the secondary flow pattern and heat transfer, while the heat flux has a smaller impact on the secondary flow pattern and heat transfer differences.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Kitti Nilpueng, Mehrdad Mesgarpour, Lazarus Godson Asirvatham, Ho Seon Ahn, Omid Mahian, Somchai Wongwises, Ahmet Selim Dalkilic
Summary: The study investigated the effects of different shapes, orientations, and distances on the air flow and heat transfer characteristics inside plate pin fin heat sinks. Results showed that under the same area, square pin fin heat sinks had higher heat transfer coefficient and pressure drop compared to circular pin fin heat sinks, while decreasing the distance led to an increase in heat transfer coefficient and pressure drop.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Xiao Sun, Sizhuo Li, Bo Wang, Bo Jiao, John Pfotenhauer, Franklin Miller, Zhihua Gan
Summary: A one-dimensional numerical model based on slug flow is developed to predict the thermal performance of cryogenic PHPs, demonstrating good predictive ability. The study shows that the response time of the hydrogen PHP to heat load changes is less than 5 s, and the vapor bubbles in the evaporator can be in a superheated state with similar proportions of sensible heat and latent heat in heat transfer.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
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)