Case Studies in Thermal Engineering最新文献_第2页

A coupling study of scavenging effect on pollutant formation and unclean combustion of a linear vibration engine

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-15 DOI: 10.1016/j.csite.2024.105650

Liu Chunzhi, Zicheng Yuan, Jiangchuan Lu, Chenheng Yuan

{"title":"A coupling study of scavenging effect on pollutant formation and unclean combustion of a linear vibration engine","authors":"Liu Chunzhi, Zicheng Yuan, Jiangchuan Lu, Chenheng Yuan","doi":"10.1016/j.csite.2024.105650","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105650","url":null,"abstract":"Linear vibration engines, due to their flexible compression expansion characteristics and the coupling mechanism of vibration, combustion, and gas exchange, are expected to become the research focus of new clean energy conversion devices. This paper develops a systematical dynamic-thermodynamic model that mutually transfers the interaction parameters between combustion model, pollution model and the insight the of a linear diesel engine, and an iterative calculation schedule is proposed to solute the systematical model for the simulation of scavenging pressure effect on combustion and pollution. The results indicate that when the scavenging pressures are considered from 1.1 bar to 1.7 bar in 0.1 bar interval, there is an optimum scavenging pressure of 1.3 bar for fast combustion, more heat release, high thermal efficiency, because it provides fast reciprocating, large compression ratio, high in-cylinder gas pressure and temperature, bringing CO concentration of 0.12 % and NO mass fraction of 0.032 %. Decreasing the scavenging pressure leads to slow compression and more residual exhaust gas for incomplete combustion, and the max HC and soot concentrations are 0.080 % and 2.5e-8 respectively. Enhancing the pressure gives low compression ratio for combustion and reduces NO concentration to 0.019 % and soot concentration to 1.1e-8.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"11 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Temperature field analysis of an air-water composite cooling high-speed generator

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-15 DOI: 10.1016/j.csite.2024.105646

Tang Chenqi, Yu Zhongjun, Fu Jia, Yang Juntan, Jiang Hao

引用次数: 0

Numerical analysis of shell and tube heat exchanger with combination of different baffles

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-15 DOI: 10.1016/j.csite.2024.105658

Muhammad Waleed, Syed Murawat Abbas Naqvi, Hammad Mustafa, Mohammed K. Al Mesfer, Mohd Danish, Kashif Irshad, Hasan Shahzad

{"title":"Numerical analysis of shell and tube heat exchanger with combination of different baffles","authors":"Muhammad Waleed, Syed Murawat Abbas Naqvi, Hammad Mustafa, Mohammed K. Al Mesfer, Mohd Danish, Kashif Irshad, Hasan Shahzad","doi":"10.1016/j.csite.2024.105658","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105658","url":null,"abstract":"Shell and tube heat exchangers (STHXs) are special systems that transfer thermal energy, and they have a significant position in numerous industries. The structure and arrangement of baffles play a vital role in boosting heat transfer rate, increasing thermo-hydraulic performance, and reducing the pumping cost. The numerical study is based on computational fluid dynamics (CFD) to run and investigate 3-D turbulent flow in the STHXs and the thermal performances of two unique combinations of baffles. The combination of double and triple flower baffles (COMB-A) and the combination of triple and novel quadruple flower baffles (COMB-B) are compared with double flower baffle (DFB) and triple flower baffle (TFB). The numerical model of STHX with segmental baffles (SGB) shows promising results while validating it with the previously published results. In the same way, the thermo-hydraulic performances of DFB-STHX, TFB-STHX, COMB-A STHX, and COMB-B STHX are evaluated and then compared. Based on numerical results, the heat transfer rate of COMB-B STHX is greater than DFB-STHX by 6.80 % and 10.76 % than the TFB-STHX. The pressure drop on the shell side for two novels STHXs i.e. COMB-A STHX and COMB-B STHX is reduced by 7.74 %, and 9.39 %, respectively, as compared to DFB-STHX. The comprehensive performance of COMB-A STHX and COMB-B STHX is better than that of the STHX with common flower baffles by 4.16 % and 8.16 % respectively. On the shell side, the fluid flow behavior in COMB-A STHX and COMB-B STHX improves the interaction between cold and hot fluids to optimize thermo-hydraulic performance.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"91 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rapid analysis of temperature fields in electronic enclosures based on the finite difference thermal resistance network method

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-15 DOI: 10.1016/j.csite.2024.105651

Xiaoyue Zhang, Yinmo Xie, Bing Liu, Yingze Meng, Kewei Sun, Guangsheng Wu, Jianyu Tan

{"title":"Rapid analysis of temperature fields in electronic enclosures based on the finite difference thermal resistance network method","authors":"Xiaoyue Zhang, Yinmo Xie, Bing Liu, Yingze Meng, Kewei Sun, Guangsheng Wu, Jianyu Tan","doi":"10.1016/j.csite.2024.105651","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105651","url":null,"abstract":"With the accelerated pace of functional updates and iteration in electronic enclosures design, the thermal design cycle is continuously shortened. However, the computational process of numerical simulation methods based on the finite element method (FEM) and finite volume method (FVM) is time-consuming, which limits the speed of product development. To enhance thermal design efficiency, this paper introduces the finite difference method (FDM) into the thermal resistance network model, establishing a three-dimensional thermal resistance network model for the electronic enclosure and employing an implicit difference scheme to solve its temperature field. Firstly, an experimental system for thermal analysis of a phase transition module was constructed to verify the feasibility of this model. The results demonstrate that the finite difference thermal resistance network model provides good accuracy, with a maximum average error of only 6.78 %. Subsequently, the model was applied to conduct thermal analysis on different functional modules and was compared with the FVM approach. The results indicate that this model not only accurately represents the temperature field but also controls the maximum relative error within 5 %, achieving a 99.67 % reduction in calculation time. This model can provide a valuable reference for future thermal design and temperature field predictions.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"24 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of the effect of eccentricity and shell diameter on the charging performance of erythritol for thermal energy storage

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-15 DOI: 10.1016/j.csite.2024.105648

Amr Rabiea, Taher Halawa

{"title":"Investigation of the effect of eccentricity and shell diameter on the charging performance of erythritol for thermal energy storage","authors":"Amr Rabiea, Taher Halawa","doi":"10.1016/j.csite.2024.105648","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105648","url":null,"abstract":"This study investigates the effect of changing eccentricity and shell diameter on the charging performance of latent heat thermal energy storage systems (LHTES). A three-dimensional numerical model was developed to simulate the melting process of erythritol as a phase change material (PCM) in a horizontal double pipe heat exchanger. The results demonstrate that increasing eccentricity significantly enhances charging performance, with optimal relative eccentricity values between 0.6 and 0.7 across various shell diameters. Under optimal conditions, all shell diameters showed at least a 32 % improvement in charging efficiency, reducing charging time by a minimum of approximately 4 h. Larger shell diameters showed greater sensitivity to eccentricity changes, with charging time reductions up to 43 % for a 133 mm shell. The study also reveals that eccentricity promotes more uniform temperature profiles and accelerates the charging process by enhancing natural convection. These findings provide valuable insights for optimizing latent heat thermal energy storage designs, particularly for larger-scale applications.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"114 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermally radiative water-based hybrid nanofluid with nanoparticles and gyrotactic microorganisms past a stretching surface with convective conditions and porous media

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-14 DOI: 10.1016/j.csite.2024.105644

Humaira Yasmin, Rawan Bossly, Fuad S. Alduais, Afrah Al-Bossly, Anwar Saeed

{"title":"Thermally radiative water-based hybrid nanofluid with nanoparticles and gyrotactic microorganisms past a stretching surface with convective conditions and porous media","authors":"Humaira Yasmin, Rawan Bossly, Fuad S. Alduais, Afrah Al-Bossly, Anwar Saeed","doi":"10.1016/j.csite.2024.105644","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105644","url":null,"abstract":"The presence of nanoparticles in the pure fluid can considerably improve the heat and mass transference properties of fluid. Such types of fluids have various applications in cooling systems, heat exchangers, and thermal management system where effectual heat transfer is essential. Therefore, in this analysis, we have examined the flow of a water-based hybrid nanofluid containing copper (Cu) and alumina (Al2O3) nanoparticles along with gyrotactic microorganisms on an elongated sheet. The analysis is done via the bvp4c MATLAB function in order to analyze the current model numerically by implementing convective boundary conditions. From the results obtained, we observed that greater magnetic fields and porous media decreased both primary and secondary velocities. It is detected that the greater ratio factor has a direct relation with the secondary velocity distribution while it has an indirect relation with the primary velocity distribution. The nanoparticle volume fraction distribution has been increased by the thermophoresis factor while reduced by the Schmidt number and Brownian motion factor. The greater magnetic, Brownian motion, heat source, thermal radiation factors, and thermophoresis factors have increased the heat transfer rate. The greater Schmidt number and Brownian motion factor have increased the Sherwood number while it has been reduced by the greater thermophoresis factor.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"11 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Energy management strategies for hybrid diesel vehicles by dynamic planning embedded in real-world driving emission model

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-14 DOI: 10.1016/j.csite.2024.105643

Yingzhang Wang, Li Zhang, Yang Chen, Chaokai Li, Baocheng Du, Jinlin Han

{"title":"Energy management strategies for hybrid diesel vehicles by dynamic planning embedded in real-world driving emission model","authors":"Yingzhang Wang, Li Zhang, Yang Chen, Chaokai Li, Baocheng Du, Jinlin Han","doi":"10.1016/j.csite.2024.105643","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105643","url":null,"abstract":"The optimization of energy management strategy for hybrid vehicles is often based on engine steady performance data and the standard driving cycle conditions in the laboratory. However, these methods cannot fully capture the vehicle’s dynamic characteristics under real-world driving conditions. This study uses a BP-Adaboost algorithm combined with a transfer learning strategy to construct a learning model of real-world driving emissions based on several real-world driving emission tests of a hybrid diesel light truck. The real-world driving emission model is then embedded into the dynamic planning algorithm using a bi-variate interpolation algorithm on the state-space plane. Accordingly, the optimal engine and motor torque control under real-world driving conditions is determined. It is found that the energy management strategies balancing the CO<ce:inf loc=\"post\">2</ce:inf> and NO<ce:inf loc=\"post\">x</ce:inf> emissions for the hybrid diesel light truck can obtain a good NO<ce:inf loc=\"post\">x</ce:inf> emission benefit while slightly sacrificing the CO<ce:inf loc=\"post\">2</ce:inf> emission benefit, and the trade-off consideration between energy consumption, pollutant emissions, and state-of-charge maintenance leads to a better overall social and economic benefit.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"19 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of heat generation and absorption on thermal radiative MHD flow of chemically reacting Casson nanofluids over a wedge

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-13 DOI: 10.1016/j.csite.2024.105637

S. Venkateswarlu, B. Hari Babu, M. Veera Krishna

{"title":"Effects of heat generation and absorption on thermal radiative MHD flow of chemically reacting Casson nanofluids over a wedge","authors":"S. Venkateswarlu, B. Hari Babu, M. Veera Krishna","doi":"10.1016/j.csite.2024.105637","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105637","url":null,"abstract":"In engineering and technology, particularly in designing structures like ships, it can be difficult to allow fluids (like water) to flow smoothly around them. This is called a \"fluid combination problem.\" It is especially important when designing the hull (the bottom part) of ships. Engineers need to calculate the impact of water pressure on the hull and how the water's surface changes. These calculations help make sure that the hull is strong enough to handle different conditions, like waves or fast-moving water. In many engineering problems, geometries like wedges are used to model flow around objects. Studying flow over a wedge helps in understanding how fluids behave near sharp edges. This investigation represents the effect of thermal radiation, viscous dissipation on MHD of a chemically reacting flow of the Casson nanofluid across the moving wedge by the convective boundary conditions with internal heat generation/absorption. Silicon Dioxide (SiO₂) nanofluids are considered. The basic governing partial differential equations are converting into nonlinear ordinary differential equations with employing suitable similarity transformations. The resultant coupled non-linear ordinary differential equations are effectively solved numerically by the aid of MATLAB software. The variations of the relevant parameters on the velocity, temperature and concentration are investigated through graphs. The numeral quantities of skin friction coefficients, Nussult number and Sherwood numbers exhibited for the several sets of values of the physical parameters using graphical profiles. To vindicate the current analysis, the computational outputs are comparing by the previous available works which is accessible in the literature and they determined to be in the good concurrence. The main findings are the nanoparticle concentration profile decrease by increasing the values of the chemical reaction, Brownian motion and Schmidt parameter, and increases with enhance in the thermophoresis parameter.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"11 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling the influence of external heat flux on thermal characteristics of the silica aerogel/paraffin in a cylindrical atomic duct

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-12 DOI: 10.1016/j.csite.2024.105633

Lishan Geng, Ali B.M. Ali, Shahram Babadoust, Anjan Kumar, Barno Abdullaeva, Rasha Abed Hussein, Soheil Salahshour, Sh Esmaeili

{"title":"Modeling the influence of external heat flux on thermal characteristics of the silica aerogel/paraffin in a cylindrical atomic duct","authors":"Lishan Geng, Ali B.M. Ali, Shahram Babadoust, Anjan Kumar, Barno Abdullaeva, Rasha Abed Hussein, Soheil Salahshour, Sh Esmaeili","doi":"10.1016/j.csite.2024.105633","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105633","url":null,"abstract":"As the price of fuel rises and the environmental impact of greenhouse gases intensifies, a larger population is opting for alternative sources of sustainable energy. Currently, scientists are facing challenges in discovering an energy-saving method that is effective in diverse scenarios and is user-friendly. Many individuals are interested in using materials that can transition between solid, liquid, and gas states. The objective was to use these materials for heat retention. Silica aerogels exhibit effective thermal regulation, regardless of whether the environment is hot or cold. Phase change materials are substances that store thermal energy effectively and play a crucial role in maintaining temperature stability. This research explored how external heat flux affected the behavior of a tube filled with silica aerogel and phase change materials. Additionally, we incorporated CuO nanoparticles to evaluate their impact on the system. The study utilized LAMMPS software to perform molecular dynamics simulations for this purpose. To achieve our goal, we evaluated various aspects of virtual structure, which can be influenced by factors, such as density, velocity, temperature profile, heat flux, thermal conductivity, and the duration of filling and emptying. The findings indicate that as external heat flux increased, maximum density decreased to 0.1364 atoms/Å³. Conversely, thermal conductivity, maximum velocity, and temperature increase to 1.97 W/m·K, 0.0138 Å/fs, and 649 K, respectively. Also, with maximum external heat flux, charging time decreases to 5.94 ns, while discharge time is recorded at 8.56 ns. Increased external heat flux resulted in greater thermal energy transfer to the material, causing the atoms to vibrate more vigorously and collide more frequently.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"13 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical modeling of wall-to-cluster heat transfer in swirling fluidized beds based on MFiX-DEM approach

IF 6.8 2区工程技术

Case Studies in Thermal Engineering Pub Date : 2024-12-12 DOI: 10.1016/j.csite.2024.105634

Anjun Li, Xiaoyu Li, Xiaogang Xu, Yuekan Zhang, Liyun Zhu, Peikun Liu

{"title":"Numerical modeling of wall-to-cluster heat transfer in swirling fluidized beds based on MFiX-DEM approach","authors":"Anjun Li, Xiaoyu Li, Xiaogang Xu, Yuekan Zhang, Liyun Zhu, Peikun Liu","doi":"10.1016/j.csite.2024.105634","DOIUrl":"https://doi.org/10.1016/j.csite.2024.105634","url":null,"abstract":"The introduction of a tangential velocity component in swirling fluidized beds enhances mixing and heat transfer. Particle clusters are common mesoscale structures in gas-solid flow systems. This study investigated the dynamic and thermal behaviors of cold particle clusters impacting a high-temperature cylindrical wall under centrifugal effects using the MFiX-DEM approach coupled with particle-scale heat transfer models. The effects of centrifugal force parameters—such as tangential velocity, reactor radius, particle number, diameter, and density—were analyzed. Results indicate that all parameters, except particle density, significantly impact wall-particle collision. Higher heat transfer can be achieved with increased tangential velocity, smaller reactor radius, fewer particle amount, smaller particle diameter, and lower particle density. Thermal characteristics are more susceptible to reaching saturation effects than dynamics. For instance, when the tangential velocity exceeds 0.4 m/s, the increase in heat absorption does not exceed 2.85 %. However, both angular velocity and contact force continue to increase significantly. Finally, the correlation between Reynolds number, Archimedes number, the ratio of cluster size to reactor size, and Nusselt number is established.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"70 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0