Journal of fluid flow, heat and mass transfer最新文献_第3页

Experimental and Numerical Study of Boiling HFE-7100 in a Vertical Mini-channel HFE-7100在垂直小通道内沸腾的实验与数值研究

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.012

Robin Lioger--Arago, P. Coste, N. Caney

{"title":"Experimental and Numerical Study of Boiling HFE-7100 in a Vertical Mini-channel","authors":"Robin Lioger--Arago, P. Coste, N. Caney","doi":"10.11159/jffhmt.2022.012","DOIUrl":"https://doi.org/10.11159/jffhmt.2022.012","url":null,"abstract":"- Using a boiling fluid, to cool electronic components, is a very efficient mode of heat transfer to dissipate high fluxes, often used in a micro/mini channel flow. In addition, the prediction of the critical heat flux (CHF) is interesting for damage prevention. For such applications, better designs require to understand confined convective boiling and to accurately quantify the local heat transfer. Two-phase CFD modelling of such flows helps in the design of cooling systems. This paper introduces the comparison between experimental and Computational Fluid Dynamic (CFD) simulation results of boiling heat transfer of HFE-7100 in a vertical mini channel. The channel is rectangular, 1 mm deep, 30 mm wide and 120 mm long. Measurements and simulations are carried out from the onset of boiling to dry-out, for three mass fluxes (G =140, 390 and 648 kg/(m².s)). The main objective of the experiment is to determine the heat transfer and to characterize the dry-out phenomenon. The local heat transfer coefficient is evaluated using a 2D inverse heat conduction method. An Eulerian multiphase 2D approach with Critical Heat Flux (CHF) wall-boiling model is used to simulate the two-phase flow. Finally, the comparison between CFD and experimental boiling curve and axial heat transfer coefficient profiles are illustrated. The numerical simulation shows a satisfactory prediction of the experimental heat transfer coefficients and the dry-out","PeriodicalId":92806,"journal":{"name":"Journal of fluid flow, heat and mass transfer","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90084338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Hydrogen/Air Supersonic Combustion Modelling and Validation for Scramjet Applications 氢/空气超声速燃烧模型及超燃冲压发动机应用验证

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.017

G. Saccone, P. Natale, L. Cutrone, M. Marini

引用次数: 1

Assessment of Concentrated Photovoltaic Thermal (CPVT) Systems Using CFD Analysis 基于CFD分析的聚光光伏热(CPVT)系统评价

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.020

Rida Ali Hmouda, Y. Muzychka, X. Duan

{"title":"Assessment of Concentrated Photovoltaic Thermal (CPVT) Systems Using CFD Analysis","authors":"Rida Ali Hmouda, Y. Muzychka, X. Duan","doi":"10.11159/jffhmt.2022.020","DOIUrl":"https://doi.org/10.11159/jffhmt.2022.020","url":null,"abstract":"- Concentrated Photovoltaic Thermal (CPVT) systems play an important role in solar system development, reducing dependency on fossil fuels and meeting global energy demand. This research investigates the CPVT model, which uses point-focus Fresnel lenses (PFFL) to amplify a significant amount of irradiance and focus it on photovoltaic surfaces to simultaneously produce electrical and thermal energy. The proposed model has Multi-Junction Photovoltaic (MJPV) solar cells, PFFL, copper heat sinks, and a copper cooling pipe. A numerical model was developed to investigate and evaluate the thermal and electrical performance of the proposed model under various input and output parameters. The numerical model has been first validated and then used to simulate the impact of the concentration ratio (CR), Heat transfer fluid (HTF) flow rates, HTF inlet temperature, incident radiation, and the optical efficiency of the Fresnel lens on the HTF outlet temperature, MJPV cell temperature, and thermal and electrical efficiency. The CFD model's minimum and maximum thermal output efficiencies were around 59.5% and 85.3%, respectively. The highest electrical efficiency occurred at a mass flow rate of 0.025 kg/s, CR = 100x, and its value was 35.74%. Further, the results show that the maximum thermal and electrical energies were 618.5 W and 219.35 W, respectively. The numerical model was validated with experimental data and demonstrated that the maximum error between the experimental and CFD models was less than 5%, confirming that the results are satisfactory and agree well with the experimental results. Finally, the results show that CPVT is a promising renewable energy system with excellent opportunities to compete with conventional power generation systems.","PeriodicalId":92806,"journal":{"name":"Journal of fluid flow, heat and mass transfer","volume":"313 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81698122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Simulation of Innovative Air Capture Systems Based on Bladeless Technology with Coandă effect 基于coandi效应的无叶片创新空气捕获系统的数值模拟

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.001

M. Carlini, A. Mennuni, Mirko Rotondo, S. Morelli

引用次数: 0

Parameterization of Layered Materials for Surface Temperature Control 层状材料表面温度控制的参数化

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.011

E. Jr., S. Ramsey, T. Mayo, J. Duncan, S. Lambrakos

引用次数: 0

Numerical Study of Electric Motors Cooling Using an Axial Air Flow 轴向气流冷却电机的数值研究

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.013

Ahmed M. Teamah, Mohamed S. Hamed

{"title":"Numerical Study of Electric Motors Cooling Using an Axial Air Flow","authors":"Ahmed M. Teamah, Mohamed S. Hamed","doi":"10.11159/jffhmt.2022.013","DOIUrl":"https://doi.org/10.11159/jffhmt.2022.013","url":null,"abstract":"– A numerical study has been carried out considering the heat transfer inside a four-pole synchronous electric motor. The computational work has been carried out using the commercial package ANSYS-CFX 2021 R1. The focus of this study is on the effect of an axial air flow passing through the gap between the stator and the rotor. The rate of cooling of the axial flow in terms of the average Nusselt number has been investigated at different rotational speeds and air flows. All surfaces were considered smooth. The source of heat generation was considered only within the rotor from the electrical windage resistance while the stator was considered insulated. The effect of the rotational speed and axial flow has been represented by a rotational and an axial Reynolds number which were varied in the ranges of 1750- 27000 and 2140- 6425, respectively. The numerical results have been validated using published experimental data with an acceptable deviation. Results showed that the average Nusselt number increases with both the rotational and the axial Reynolds numbers. However, the axial Reynolds number has a more dominant effect on the rate of cooling than the rotational Reynolds number.","PeriodicalId":92806,"journal":{"name":"Journal of fluid flow, heat and mass transfer","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90367040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Parametric Study of Fluid Injection Winglet on Aerodynamic Performance of the Wing 射流小翼对机翼气动性能的参数化研究

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.003

Hariprasad Thimmegowda, Yadu Krishnan S, Gisa G S, Vootukuri Gowtham Reddy

引用次数: 1

Auxetic Lattice Structures for Turbomachinery Application – a Simulative Parameter Study 涡轮机械中辅助晶格结构的模拟参数研究

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.016

Stefan Schröter, Lukas Reisinger, V. Gümmer

引用次数: 0

Flow Resistance of Randomly Packed Beds of Crushed Rock and Ellipsoidal Particles using CFD 基于CFD的碎石和椭球颗粒随机堆积床的流动阻力研究

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.002

J. Hoffmann, Tapiwa Manatsa, Jeroen Houtappels

{"title":"Flow Resistance of Randomly Packed Beds of Crushed Rock and Ellipsoidal Particles using CFD","authors":"J. Hoffmann, Tapiwa Manatsa, Jeroen Houtappels","doi":"10.11159/jffhmt.2022.002","DOIUrl":"https://doi.org/10.11159/jffhmt.2022.002","url":null,"abstract":"- Rock bed thermal energy storage is a cost-effective solution to store waste heat from a solarized Brayton cycle for use in a Rankine cycle after sunset. However, rock bed thermal energy storage systems for utility scale concentrated solar power are huge and require multiple air inlets and outlets. As a result, the flow inside the bed is fully three dimensional and deviates considerably from plug flow conditions usually encountered in chemical reactors. Designing a rock bed thermal energy storage system for the minimum capital cost and pumping power depend on reliable predictions of the fluid flow paths and temperature profiles in the bed. Particle size and shape have a significant influence on how the particles will pack down, which in turn influences the flow pattern in the bed, and hence the pressure drop and heat transfer characteristics of the bed. In this work, we discuss the characterization of crushed rock particles and concluded that there are benefits in approximating particles by mono-dispersed ellipsoids. We used discrete element modelling to generate packed beds of the ellipsoidal particles, and computational fluid dynamics to model the flow in the interstitial voids. This way, we successfully captured the directional effect of the flow resistance for ellipsoidal particles in terms of sphericity,  porosity  particle diameter D ve , and particle Reynolds number Re Our current model under-predicted the pressure drop across a packed bed of crushed rock particles.","PeriodicalId":92806,"journal":{"name":"Journal of fluid flow, heat and mass transfer","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88777618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Numerical Investigation of Convective Heat Transfer during Orthogonal Cutting Processes 正交切削过程对流换热的数值研究

Journal of fluid flow, heat and mass transfer Pub Date : 2022-01-01 DOI: 10.11159/jffhmt.2022.021

T. Helmig, T. Göttlich, Hui Liu, T. Bergs, R. Kneer

引用次数: 1