Article
Thermodynamics
Luiz Otavio Ferrao Teixeira Alves, Jorge R. Henriquez, Jose Angelo P. da Costa, Vagner Abramchuk
Summary: In this study, a comparative analysis of engine coolant type was conducted using a conjugate heat transfer simulation. The addition of Al2O3 and CuO nanoparticles improved the cooling capacity but had a negative effect on the flow velocity.
Article
Energy & Fuels
Sean Moser, K. Dean Edwards, Tobias Schoeffler, Zoran Filipi
Summary: Thermal barrier coatings (TBCs) play a crucial role in mixing controlled combustion, with material properties and structure affecting efficacy, and the study aims to provide design guidance and address obstacles. By coupling CFD modeling and FEA simulation, spatial and temporal thermal boundary conditions in combustion processes can be resolved.
Article
Physics, Multidisciplinary
Luc Potier, Florent Duchaine, Benedicte Cuenot, Didier Saucereau, Julien Pichillou
Summary: Although significant progress has been made in understanding and mastering the major physics of cryogenic rocket engines, the injection system and wall heat transfer still pose critical challenges. Simulating the atomization process remains a practical limitation in industrial systems. The injection model has a crucial impact on flame stabilization and wall heat fluxes, which are vital for wall-cooling systems. The proposed methodology in this study utilizes advanced numerical simulations to predict flame topology and associated heat fluxes, considering factors such as liquid injection, combustion, and wall treatment.
Article
Thermodynamics
Michael J. Tess, Vamshi Korivi, Eric Gingrich, Peter Schihl
Summary: Simultaneous measurements of global engine heat transfer and subsurface piston temperatures were used to evaluate the potential of prolonged combustion duration to minimize heat rejection in a diesel engine. The results suggest that the duration of the spray and combustion processes did not greatly influence gross indicated thermal efficiency (ITEg) or global heat transfer from the engine, except for extremely long combustion durations. Analysis of the piston temperature measurements revealed that smaller orifice diameter injectors increased piston temperatures locally, while lower injection pressures decreased piston temperatures on the bowl rim.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2023)
Article
Energy & Fuels
Faisal Mehmood, Hussain Ahmed Tariq, Muhammad Anwar, Hassan Elahi, Muhammad Raheel Bhutta, Talha Irfan Khan, Asif Israr, Muhammad Umer, Usama Waleed Qazi, Usman Ghafoor
Summary: A study was conducted to reduce the peak temperature at the top dead center (TDC) of a spark ignition engine cylinder using square pin fins. The results showed that using 4x4x4 mm fins with a spacing of 2 mm significantly reduced the peak temperature at TDC, and the heat transfer effectiveness was calculated as 3.32.
Article
Thermodynamics
Abhishek L. Pillai, Reo Kai, Takuya Murata, Takato Ikedo, Ryo Masuda, Ryoichi Kurose
Summary: This study investigates the heat transfer mechanism between impinging spray flame and wall under CI engine-like conditions using 3-Dimensional numerical simulations. The results show that the wall heat flux is highest in the stagnation zone where the spray flame directly impacts the wall surface, and the radiative heat flux increases with the distance from this zone. Additionally, the influence of fuel injection velocity on the radiative heat flow rate at the wall surface is small.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
P. Olmeda, X. Margot, P. Quintero, J. Escalona
Summary: The paper presents an analytical solution to determine the wall temperature of surfaces coated with multi-layer coatings and compares it with another methodology to address the 3D conjugate heat transfer problem.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Henrique L. Castro, Marcelo M. Ganzarolli, Andre D. Rocha
Summary: This work presents an experimental and numerical study of turbulent conjugate natural convection heat transfer in a plate with protruding heat sources, considering thermal radiation effects. The results show that heat loss by radiation is significant, heat transfer efficiency decreases with increasing downward angle, and there is a jump in the average Nusselt number due to plume detachment in the upward cases. A correlation for the Nusselt number is developed.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Wandong Zhao, Ruijie Li, Hailing Li, Ying Zhang, Songgang Qiu
Summary: This study conducted a comprehensive 3D modeling of the fluid dynamics and heat transfer in an advanced free-piston Stirling engine, investigating the accuracy of different turbulent CFD models and finding that the k-epsilon turbulence model with improved wall treatment yields reasonable accuracy and stable convergence. Results also indicate that the temperature, pressure, and density inside the regenerator exhibit non-uniform distribution during operation.
APPLIED THERMAL ENGINEERING
(2021)
Article
Multidisciplinary Sciences
Decang Lou, Mengjun Wang, Jinhua Liang, Jun Zeng, Xiaoyang Huang, Along Chen
Summary: This study proposes an optimization method based on the sensitivity of global and local geometric parameters to improve the cooling efficiency of the E3 engine nozzle guide vane. By ranking the sensitivity of 29 geometric parameters and selecting influential variables, the maximum surface temperature of the vane is effectively reduced. Furthermore, the introduction of a new duck-paw type film cooling hole helps to further reduce local temperatures.
Article
Thermodynamics
Francesco Nasuti, Andrea Torricelli, Sergio Pirozzoli
Summary: A computational study was conducted on conjugate heat transfer in liquid propellant rocket engines, showing that reduced solid thermal conductivity leads to decreased overall thermal efficiency. While the RANS/Fourier solver accurately estimates pressure drop, predictions of thermal effects generally have larger differences.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Minlin Yang, Elaine Low, Chung Lim Law, Jie-Chao Chen, Pau Loke Show, Si-Min Huang
Summary: The study focuses on the performance of a membrane-based absorption heat pump in recovering low-temperature waste heat from used cooling water. By optimizing the design of the air gap width, the solution temperature can be significantly increased, leading to improved efficiency and performance of the heat pump.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
P. W. Agostinelli, D. Laera, I. Boxx, L. Gicquel, T. Poinsot
Summary: The study shows that thermal wall boundary conditions have a significant impact on the accuracy and stability of flame prediction, and adopting the full Conjugate Heat Transfer method can achieve more stable results.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
J. W. Elliott, M. T. Lebon, A. J. Robinson
Summary: Increasing power densities in modern CPUs have led to high temperature regions on the semiconductor die, affecting performance and reliability. A study on imposing a non-uniform heat transfer coefficient profile on the CPU's heat spreader surface showed that multi-objective optimization achieved the best heat transfer coefficient distribution, resulting in reduced temperature and temperature gradient across the heat source.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Kizuku Kurose, Takuya Kawasuso, Kazushi Miyata, Yoshinori Hamamoto
Summary: A novel simulation model was developed in this study to predict the heat transfer characteristics and flow maldistribution of refrigerants flowing in parallel mini-channels with different heat fluxes or wall temperatures among channels. The model successfully predicted the flow maldistribution and various heat transfer parameters. It was found that the mean heat transfer rate of the channels decreased significantly with increasing difference in wall temperature between the channels.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Hai Zhao, Puzhen Gao, Xiaochang Li, Ruifeng Tian, Hongyang Wei, Sichao Tan
Summary: This study numerically investigates the interaction between flow-induced vibration and forced convection heat transfer in a tube bundle. The results show that the impact of flow-induced vibration on heat transfer varies in different flow velocity regions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Rohit Chintala, Jon Winkler, Sugirdhalakshmi Ramaraj, Xin Jin
Summary: The current state of fault detection and diagnosis for residential air-conditioning systems is expensive and not suitable for widespread implementation. This paper proposes a cost-effective solution by introducing an automated fault detection algorithm as a screening step before more expensive tests can be conducted. The algorithm uses home thermostats and local weather information to identify thermodynamic parameters and detect high-impact air-conditioning faults.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
A. Azimi, N. Basiri, M. Eslami
Summary: This paper presents a novel optimization algorithm for improving the water-film cooling system of photovoltaic panels, resulting in a significant increase in net energy generation.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Duc-Thuan Phung, Chin-Hsiang Cheng
Summary: In this study, a novel CFDMD model is used to analyze and investigate the behavior of thermal-lag engines (TLE). The study shows that the CFDMD model effectively captures the thermodynamic behavior of the working gas and the dynamic behavior of the engine mechanism. Additionally, the study explores the temporal evolution of engine speed and the influence of various parameters on shaft power and brake thermal efficiency. The research also reveals the existence of a thermal-lag phenomenon in TLE.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Haiying Yang, Yinjie Shen, Lin Li, Yichen Pan, Ping Yang
Summary: The purpose of this article is to find a measure to improve the interfacial thermal transfer of graphene/silicon heterojunction. Through molecular dynamics simulation, it is found that surface modification can significantly reduce the thermal resistance, thereby improving the thermal conductivity of the graphene/silicon interface.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Qiong Wu, Yancheng Wang, Haonan Zhou, Xingye Qiu, Deqing Mei
Summary: This article introduces a visible methanol steam reforming microreactor, which uses an optical crystal as an observation window and measures the reaction temperature in real-time using infrared thermography. The results show that under lower oxygen to carbon ratio conditions, the microreactor has a higher heating rate and a stable gradient in temperature distribution.
APPLIED THERMAL ENGINEERING
(2024)
Review
Thermodynamics
Giulia Manco, Umberto Tesio, Elisa Guelpa, Vittorio Verda
Summary: In the past decade, there has been a growing interest in studying energy systems for the combined management of power vectors. Most of the published works focus on finding the optimal design and operations of Multi Energy Systems (MES). However, for newcomers to this field, understanding how to achieve the desired optimization details while controlling computational expenses can be challenging and time-consuming. This paper presents a novel approach to analyzing the existing literature on MES, with the aim of guiding practical development of MES optimization. Through the discussion of six case studies, the authors provide a mathematical formulation as a reference for building the model and emphasize the impact of different aspects on the problem nature and solver selection. In addition, the paper also discusses the different approaches used in the literature for incorporating thermal networks and storage in the optimization of multi-energy systems.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xuepeng Yuan, Caiman Yan, Yunxian Huang, Yong Tang, Shiwei Zhang, Gong Chen
Summary: In this study, a multi-scale microgroove wick (MSMGW) was developed by laser irradiation, which demonstrated superior capillary performance. The surface morphology and performance of the wick were affected by laser scan pitch, laser power, repetition frequency, and scanning speed. The MSMGW showed optimal capillary performance in alumina material and DI water as the working fluid.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Maofei Mei, Feng Hu, Chong Han
Summary: This paper proposes an effective local search method based on detection of droplet boundaries for understanding the dynamic process of droplet growth during dropwise condensation. The method is validated by comparing with experimental data. The present simulation provides an effective approach to more accurately predict the nucleation site density in future studies.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Rahul Kumar Sharma, Ashish Kumar, Dibakar Rakshit
Summary: The study explores the use of phase change materials (PCM) as a retrofit with Heating Ventilation and Air-conditioning systems (HVAC) to reduce energy consumption and improve air quality. By incorporating PCM with specific thickness and fin configurations, significant energy savings can be achieved in comparison to standard HVAC systems utilizing R134a. This research provides policymakers with energy-efficient and sustainable solutions for HVAC systems to combat climate change.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Zhenhua Ren, Xiangjin Meng, Xingang Qi, Hui Jin, Yunan Chen, Bin Chen, Liejin Guo
Summary: This paper investigates the heat transfer mechanism and factors influencing thermal radiation in the process of supercritical water gasification (SCWG) of coal, and proposes a comprehensive numerical model to simulate the process. Experimental validation results show that thermal radiation accounts for a significant proportion of the total heat exchange in the reactor and a large amount of radiant energy exists in the important spectral range of supercritical water. Enhancing radiative heat transfer can effectively increase the temperature of the reaction medium and the gasification rate.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Mauro Abela, Mauro Mameli, Sauro Filippeschi, Brent S. Taft
Summary: Pulsating Heat Pipes (PHP) are passive two-phase heat transfer devices with a simple structure and high heat transfer capabilities. The actual unpredictability of their dynamic behavior during startup and thermal crisis hinders their large-scale application. An experimental apparatus is designed to investigate these phenomena systematically. The results show that increasing the number of evaporator sections and condenser temperature improves the performance of PHP. The condenser temperature also affects the initial liquid phase distribution and startup time.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Ke Gan, Ruilian Li, Yi Zheng, Hui Xu, Ying Gao, Jiajie Qian, Ziming Wei, Bin Kong, Hong Zhang
Summary: A 3-dimensional enhanced heat pipe radiator has been developed to improve heat dissipation and temperature uniformity in cooling high-power electronic components. Experimental results show that the radiator has superior heat transfer performance compared to a conventional aluminum fin radiator under different heating powers and wind speed conditions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xinyi Zhang, Shuzhong Wang, Daihui Jiang, Zhiqiang Wu
Summary: This study focuses on recovering waste heat from blast furnace slag using dry centrifugal pelletizing technology. A comprehensive two-dimensional model was developed to analyze heat transfer dynamics and investigate factors influencing heat exchange efficiency. The findings have important implications for optimizing waste heat recovery and ensuring safe operations.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xincheng Wu, An Zou, Qiang Zhang, Zhaoguang Wang
Summary: The boosting heat generation rate of high-performance processors is challenging traditional cooling techniques. This study proposes a combined design of active jet intermittency and passive surface modification to enhance heat transfer.
APPLIED THERMAL ENGINEERING
(2024)