Article
Thermodynamics
Alisan Gonul, Abdulkerim Okbaz, Nurullah Kayaci, Ahmet Selim Dalkilic
Summary: In this study, the effects of delta winglet-type vortex generators on the heat transfer enhancement and pressure loss in microchannels were investigated numerically. It was found that vortex generators significantly improve heat transfer performance with a corresponding increase in pressure loss. Multi-objective optimization and sensitivity analysis were conducted to determine the most optimum design parameters and propose practical correlations for Nusselt number and friction factor.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Seyed Mahdi Ekrani, Shayan Ganjehzadeh, Javad Abolfazli Esfahani
Summary: The present study improves the thermal-hydraulic performance of a circular tube equipped with a delta winglet vortex generator by using a numerical model, investigating two additional parameters, and developing a support vector regression (SVR) for prediction and optimization. The presence of delta winglets disrupts the boundary layer and creates swirling flow, leading to enhanced heat transfer but also increased pressure drop. The addition of SiO2 as a nanofluid further enhances heat transfer. The results of this study provide insights into the best arrangement of delta winglets for a tubular heat exchanger.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Green & Sustainable Science & Technology
Yahya Sheikhnejad, Seyed Abdolreza Gandjalikhan Nassab
Summary: The study aims to enhance the performance of planar solar chimneys by using vortex generation technique to convert more solar radiation into air enthalpy, with a passive vortex generator employed for heat transfer enhancement. Numerical results show that the natural vibration of elastic vortex generator induces moving vortices into the flow field, leading to improved natural convection heat transfer and significantly enhancing the performance of the air heater.
Article
Thermodynamics
Ahmet Umit Tepe
Summary: This study investigated the effect of a newly proposed punched triangular ramp vortex generator on heat transfer performance for a fin-tube heat exchanger through numerical simulations. The results showed that the ramp angle had a more significant influence on thermo-hydraulic performance compared to ramp height.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Mehmet Dogan, Atila Abir Igci
Summary: Vortex generators (VGs) play a crucial role in enhancing heat transfer. An experimental comparison between a novel type of vortex generator (NTVG) producing longitudinal vortex (LV) and delta winglet pair (DWP) showed that the NTVG achieved higher thermal enhancement, indicating its effectiveness in improving heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Muhammed Zafar Ali Khan, Haider Ali Khan, Muhammad Aziz
Summary: This study proposes and develops a machine learning-based approach for predicting the heat transfer performance of a heat exchanger that employs delta-wing tape inserts. By building an artificial neural network (ANN) model and training it with a large dataset, the parameters Nu, f, and eta are successfully predicted. The results show that the proposed method can accurately predict the heat transfer characteristics and provide valuable guidance for practical applications.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Changgui Xie, Gongxing Yan, Qiong Ma, Yasser Elmasry, Pradeep Kumar Singh, A. M. Algelany, Makatar Wae-hayee
Summary: This study proposes a method using response surface methodology (RSM) and artificial neural network (ANN) to optimize the design of fin-tube heat exchangers (FTHEs) with vortex generators (VGs). The results show that ANN outperforms RSM in predicting the Nusselt number and the friction factor.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
Junjie Zhao, Bin Zhang, Xiaoli Fu, Shenglin Yan
Summary: This study focuses on the impact and optimization of vortex generators in radiators on the ends of motor coils, concluding that a 45-degree attack angle generator is most effective. Results show that FD with a longitudinal distance of 4 h performs well at Reynolds numbers below 4000, while FU-4 h-0.5 h is more prominent at higher Reynolds numbers.
Article
Thermodynamics
Min Sik Kang, Sung Goon Park, Cong Truong Dinh
Summary: Heat transfer should be considered in the design process of various industrial fields, and vortex generators can be used to enhance convective heat transfer with the trade-off of increased mechanical loss due to increased pressure drop.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Xinhuan Shi, Wei Chen, Zhongchun Li, Xiaoming Chai, Minking K. Chyu
Summary: In this study, the influence of a vortex generator on liquid metal heat transfer capability was investigated. The thermo-fluid behaviors of sodium-potassium alloy under different channel structures were compared. The results showed that the rectangular ring rib channel exhibited heat transfer deterioration, while the Kagome and BCC structures effectively enhanced the heat transfer performance of the NaK alloy fluid.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Mehmet Dogan, Sait Erzincan
Summary: This study experimentally investigated the thermal performance of a novel vortex generator that can generate longitudinal vortices in a common flow-down pattern with Reynolds numbers in the range of 5000-25,000. The results showed that the best thermal enhancement was achieved with a transverse pitch ratio of 0.12 and a longitudinal pitch ratio of 1.5. Furthermore, the inline arrangement of the vortex generators was found to be more efficient than the staggered arrangement in terms of thermal performance.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Chunhua Min, Haizhu Li, Xiaomeng Gao, Kun Wang, Liyao Xie
Summary: This paper proposed a novel method to improve heat exchanger thermal performance by combining vortex generators and twisted belts, with numerical studies on circular tube thermo-hydraulic characteristics to determine optimal parameters. The results showed that using a combination of staggered arrangement, optimal twist ratio of 4, attack angle of 75 degrees, and pitch of 1.5D can significantly enhance the heat exchanger performance.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Xinhuan Shi, Lanxin Wang, Wei Chen, Zhongchun Li, Xiaoming Chai, Minking K. Chyu
Summary: The helium-xenon mixture is an excellent choice as a coolant for gas-cooled reactors in deep space exploration. To optimize its heat exchanger for lightweight and compact designs, the influence of three internal vortex generators on heat transfer enhancement was investigated. The results showed that the induced vortex system significantly improved heat transfer capability and performance, with the Body-Centered Cubic (BCC) lattice array demonstrating the best thermal efficiency.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Chemical
Pongjet Promvonge, Sompol Skullong
Summary: This study investigates the thermal-hydraulic performance of a solar receiver channel equipped with a vortex flow generator. The use of square flaps on the V-baffle helps reduce pressure drag and friction loss. The optimum thermal performance is achieved with a flap angle of 45 degrees and a relative baffle pitch of 1.5.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2022)
Article
Thermodynamics
Lijun Wang, Bingyu Chen, Yuncong Jiang, Xiaokang Yan
Summary: The study compared the heat transfer capacity of concave VG, convex VG, and trapezoidal VG, with concave VG found to have a more reasonable heat transfer capacity, enhancing heat transfer efficiency and reducing resistance loss. Nusselt number (Nu) has a strong correlation with volume averaged turbulent dissipation rate and wall shear stress, with a correlation coefficient of 0.935.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
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)