Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC)最新文献_第2页

A SIMULATION STUDY ON FIRE SERVICE INTERVENTION IN ROCK CAVERN WITH TILTED ACCESS TUNNEL 倾斜巷道岩洞消防干预模拟研究

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.cbf.031768

H. L. Tsang, N. Fong, W. Chow

{"title":"A SIMULATION STUDY ON FIRE SERVICE INTERVENTION IN ROCK CAVERN WITH TILTED ACCESS TUNNEL","authors":"H. L. Tsang, N. Fong, W. Chow","doi":"10.1615/tfec2020.cbf.031768","DOIUrl":"https://doi.org/10.1615/tfec2020.cbf.031768","url":null,"abstract":"The firefighting and rescue operations to be carried out by fire-fighters may be hampered by the complexity of the design layout of rock caverns especially at the initial stage of firefighting and leading the evacuees to escape. The problem may be escalated in case of only limited means of access leading to the interior of the rock cavern provided. The situation may be exacerbated in case that the access tunnel is designed as a descending tunnel instead of horizontal tunnel given that the large amount of smoke/flammable gases is accumulated at main entrance with larger tilted angle. This paper aims at exploring the potential risks to be encountered by the fire-fighters when they arrive at scene of a fire involving a rock cavern with various types of access tunnel. Two types of design fire sizes in three types of access tunnel, e.g. horizontal, ascending, descending tunnels with different tilted angles to a cubic cavern space were studied by Computational Fluid Dynamics (CFD) simulations as well. Various correlations of key scientific criteria affecting fire service intervention in rock cavern were identified and discussed. Subsequently, according to the predicted results, recommendations in terms of mitigations on inherent risks of barrier to fire service intervention in rock caverns are proffered.","PeriodicalId":434777,"journal":{"name":"Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127542948","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

A MULTIPHASE, RIEMANN-SOLVER APPROACH TO GAS-CAVITATION 气穴化的多相、黎曼求解方法

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.mph.031923

Andris Rambaks, H. Murrenhoff, K. Schmitz

引用次数: 0

SIMULATION OF NATURAL CONVECTION IN A SQUARE CAVITY WITH PARTIALLY HEATED AND COOLED VERTICAL WALLS 垂直壁面部分加热和部分冷却的方形空腔内自然对流的模拟

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.cmd.032123

E. Selamet, A. Selamet, R. Dehner

引用次数: 0

BIFURCATION PHENOMENA IN THE SHORT TAYLOR-COUETTE CAVITY WITH THE ASYMMETRIC END-WALLS AT LOW Re 低Re下端壁不对称的短TAYLOR-COUETTE腔中的分岔现象

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.fli.032358

E. Tuliszka-Sznitko

引用次数: 0

A MANY-BODY DISSIPATIVE PARTICLE DYNAMICS STUDY OF COALESCENCE INDUCED JUMPING 聚结诱导跳跃的多体耗散粒子动力学研究

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.cmd.031803

Ting Liu, A. Mishra, A. Hemeda, J. Palko, Yanbao Ma

{"title":"A MANY-BODY DISSIPATIVE PARTICLE DYNAMICS STUDY OF COALESCENCE INDUCED JUMPING","authors":"Ting Liu, A. Mishra, A. Hemeda, J. Palko, Yanbao Ma","doi":"10.1615/tfec2020.cmd.031803","DOIUrl":"https://doi.org/10.1615/tfec2020.cmd.031803","url":null,"abstract":"Coalescence induced jumping from solid surface at mesoscale is simulated using Many-body dissipative particle dynamics (MDPD). The geometrical evolution during the coalescence of two droplets and resulted jumping were obtained and the mechanism behind this phenomenon were also investigated. The jumping maps two equal-sized droplets and two droplets with different sizes were obtained. It is found the coalescence of two equal size droplets will lead to jumping when the contact angle is larger than the minimum threshold contact angle, which is about 160°. This minimum threshold contact angle is related to droplet size as it increases when droplet size decreases. Jumping can still happen when two droplets with different sizes merge together. The maximum volume ratio for jumping of two droplets with different sizes is 3.9. Velocity field shows how internal flow evolves during the coalescence process. There is obvious velocity change inside the droplet from the beginning of the droplet deformation to jumping. The energy conversion rate from released surface energy to kinetic energy is found about 1%. These results can greatly advance the fundamental understanding of hydrodynamics behavior of coalescence induced droplet jumping.","PeriodicalId":434777,"journal":{"name":"Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121405526","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

Mechanical properties of thermally stable cadmium iodoapatite ceramic by reactive spark plasma sintering technique 反应放电等离子烧结技术制备热稳定的碘磷灰石镉陶瓷的力学性能

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.aes.032443

I. Islam, Fengyuan Lu

{"title":"Mechanical properties of thermally stable cadmium iodoapatite ceramic by reactive spark plasma sintering technique","authors":"I. Islam, Fengyuan Lu","doi":"10.1615/tfec2020.aes.032443","DOIUrl":"https://doi.org/10.1615/tfec2020.aes.032443","url":null,"abstract":"Apatites based materials have been considered as potential waste forms to immobilize the long-lived radioactive iodine isotope. But the thermal instability and phase decomposition at a higher temperature hamper the waste management process. Spark plasma sintering can be a suitable technique compared to conventional sintering processes due to its rapid heating rate, lower sintering temperature and holding time. In this study, we synthesized a highly dense iodine bearing cadmium iodoapatite ceramic pellets by spark plasma sintering (SPS) technique. We successfully consolidated iodoapatite pellets with ~95.5% of theoretical density (TD) without any iodine loss and phase decomposition after low temperature sintering at 350 o C for 15 mins under 100 MPa. The theoretical density, micro-hardness, and yield strength of sintered pellets were investigated for different sintering temperatures of 300 o C, 350 o C, and 400 o C and holding time (15 min) under the pressure of 100 MPa. The densified pellets displayed nanocrystalline grain structures of 30-80 nm size which contributed to enhanced thermal stability and fracture toughness. The X-ray diffraction and EDS analysis also confirms the presence of iodoapatite structures. This advanced fabrication technique using SPS can help to develop thermally durable waste forms and mitigate the challenges to dispose high- level radioactive waste.","PeriodicalId":434777,"journal":{"name":"Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130942451","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

THE SWIRLING MOTION OF DRIBBLING HONEY 滴蜂蜜的旋转运动

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.fnc.031576

M. Molki

引用次数: 0

Effects of the laidback fan-shaped hole geometry on film cooling performance using large eddy simulation 利用大涡模拟研究扇形孔几何形状对气膜冷却性能的影响

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.cmd.032120

H. Jang, M. Tyagi

引用次数: 0

Design of a Matched Index of Refraction Facility for Flow Studies with Mixing and Complex Geometries 混合和复杂几何流动研究中折射率匹配装置的设计

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.fnd.032419

Abdullah G. Weiss, Paul J. Kristo, M. Kimber

{"title":"Design of a Matched Index of Refraction Facility for Flow Studies with Mixing and Complex Geometries","authors":"Abdullah G. Weiss, Paul J. Kristo, M. Kimber","doi":"10.1615/tfec2020.fnd.032419","DOIUrl":"https://doi.org/10.1615/tfec2020.fnd.032419","url":null,"abstract":"A matched index of refraction facility has been constructed at Texas A&M University to enable optically transparent measurements in a test section capable of laminar, transition, and turbulent flow regimes. The index matching is achieved by recirculating Drakeol ® 5 oil through a closed loop system via a centrifugal pump whose heat generation does not adversely affect the refraction. Quartz is used as the solid material inside the test section to enable the index matching. Design of the system is discussed, followed by preliminary results for three rectangular slot flows that coalesce into a single channel. Particle Image Velocimetry was employed to capture the velocities in the mixing region. This configuration allows for simultaneous measurement of the flow 0.35 hydraulic diameters upstream and 3.9 diameters downstream of the outlets. The Reynolds numbers of the three channels are in the range of 1800-20000, spanning multiple flow regimes and promoting different flow physics. Results in the turbulent regime closely resembled the interaction of three confined slot jets. The non-turbulent regime shows the fluid stalling to approximately half of its inlet velocity, prompting recirculation zones near the outlet. The dominant energy contributions and momentum dissipation in the stalling region come from shear and spanwise stresses, whereas streamwise stresses dominate in other locations. It was also observed that the shear stresses decrease with increasing bulk velocities, while the spanwise stresses remained relatively constant. The ability to simultaneously measure upstream and downstream of the outlets enables further investigation into understanding the complex interaction of the momentum exchange that occurs as a result of the geometry, flow regime, and the effect of pressure in these areas. This data also enables a straightforward exercise to help validate models of turbulence and transition for such mixing scenarios.","PeriodicalId":434777,"journal":{"name":"Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129194886","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

Development of aperture total internal reflection (A-TIR) for droplet characterization with 3-D ray tracing and modified Fresnel equation 基于三维光线追踪和修正菲涅耳方程的孔径全内反射(A-TIR)液滴表征方法的发展

Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC) Pub Date : 1900-01-01 DOI: 10.1615/tfec2020.mns.031998

I. Kim, Yang Lie, J. S. Park

{"title":"Development of aperture total internal reflection (A-TIR) for droplet characterization with 3-D ray tracing and modified Fresnel equation","authors":"I. Kim, Yang Lie, J. S. Park","doi":"10.1615/tfec2020.mns.031998","DOIUrl":"https://doi.org/10.1615/tfec2020.mns.031998","url":null,"abstract":"This study proposes and demonstrates a new approach using aperture total internal reflection (A-TIR) by means of various apertures in front of a detector to characterize micro/macro droplet. Pure liquid is used to make micro and macro scale droplets. An aperture in front of a detector in TIR configuration generates unique reflectance curve by filtering the amount of aberrated beams from the top curved profiles of droplets. A scheme of threedimensional (3-D) ray tracing is developed for the reflected beam profile from the curved surface of the droplet with the modified Fresnel modeling to show a good agreement with the measurement. The modified Fresnel modeling is proposed to consider the morphological features of the droplet such as the thickness, the diameter, the surface coverage fraction, the effective flatness ratio, and the quantum phenomenon of Goos-Hänchen (G-H) shift effect. Various sizes of apertures are employed to demonstrate the A-TIR reflectance dependence on the aperture sizes for the macro and micro-sized droplets with a good agreement between the experiment and the simulation. and 3-D ray tracing with the modified Fresnel equation shows good agreement. Furthermore, it is demonstrated that one of the morphological features of the droplet, the thickness can be successfully determined with a reasonable agreement with the measurement. This outcome can be used to determine the morphological features of droplets such as the thickness, the diameter, and the coverage fraction and to characterize uneven surface features like human fingerprinting.","PeriodicalId":434777,"journal":{"name":"Proceeding of 5th Thermal and Fluids Engineering Conference (TFEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130163636","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