Volume 7: Fluids Engineering最新文献

{"title":"Numerical CFD / FSI Study of Teflon and Dacron for Use in the Femoral Artery Graft Procedure","authors":"S. Sandhu, K. Anderson","doi":"10.1115/imece2019-10100","DOIUrl":"https://doi.org/10.1115/imece2019-10100","url":null,"abstract":"\u0000 This paper presents Fluid Structure Interaction modeling of candidate implant materials used in the femoral artery graft medical procedure. Two candidate implant materials, namely Teflon and Dacron are considered and modeled using Computational Fluid Dynamics (CFD) and structural Finite Element Analysis (FEA) to obtain Fluid Structure Interaction (FSI) developed stresses within the candidate materials as a result of non-Newtonian blood flowing in a pulsatile unsteady fashion into the femoral artery implant tube. The pertinent findings for a pulsatile velocity maximum magnitude of 0.3 m/s and period of oscillation of 2.75 sec are as follows. For the biological tissue the wall shear stress is found to be 2.15 × 104 Pa, the hoop stress is found to be 1.6 × 104 Pa. For the Teflon implant material, the wall shear stress is found to be 1.177 × 104 Pa, the hoop stress is found to be 2.2 × 104 Pa. For the Dacron implant material the wall shear stress is found to by 3.9 × 104 Pa, the hoop stress is found to be 2.17 × 104 Pa. Based upon the analysis herein the PTFE material would be recommended.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127426119","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}

{"title":"The Effect of Crosswind Velocity on the Spray Drift of Flat Fan Nozzle","authors":"S. Raza, K. Sallam, S. Post","doi":"10.1115/imece2019-12049","DOIUrl":"https://doi.org/10.1115/imece2019-12049","url":null,"abstract":"\u0000 The objective of this research project is to eliminate the spray drift caused by crosswind. Spray drift is an important problem for the agricultural industry. Some herbicides (e.g. Dicamba) can cause serious damage if it drifts to nearby crops that are not genetically modified to withstand those herbicides. Our hypothesis is that the nozzle geometry and the injection angle can be actively/passively controlled to compensate for the crosswind velocity and effectively deliver the herbicides to the target area. The measurements include the breakup regime transitions, the droplet sizes, and the droplets trajectory as function of the wind speed and the injection angle. The current results show that the crosswind modifies the primary breakup mechanism from sheet breakup regime (i.e. thinning and fragmentation of the liquid sheet into ligaments) to bag breakup regime (i.e. the formation bags along the downstream side of liquid sheet) resulting in smaller drop sizes and an increased drift flux. Techniques to eliminate the bag breakup regime are presented.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125972634","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}

{"title":"Enhancing the Cell Viability in High Throughput Deterministic Lateral Displacement Separation of Circulating Tumor Cells","authors":"Arian Aghilinejad, Christopher Landry, G. Cha, Xiaolin Chen","doi":"10.1115/imece2019-10209","DOIUrl":"https://doi.org/10.1115/imece2019-10209","url":null,"abstract":"\u0000 Cancer is among a major health concerns all over the world. Cancer metastasis, which defines as the migration of malignant cells from original sites to distant organs, is the main reason of death due to cancer and there is growing evidence that Circulating Tumor Cells (CTCs) are responsible for initiating the metastasis. Due to the importance of these bioparticles in biotechnology and medicine, there is a growing interest to study and separate them through different techniques especially microfluidic label-free technologies. One such technology, termed Deterministic Lateral Displacement (DLD) has recently shown promising abilities to separate cells and particles of different sizes. However, DLD is a separation method that takes advantages of the predictable flow laminae of low Reynolds number (Re) fluid flow. In order to achieve higher device throughput, effects of higher Reynolds number flow on DLD device should be studied. Additionally, the higher flow rates would apply higher forces and shear stresses on the cells which threaten the cell’s viability. In this study, employing numerical simulation, the effect of high Re number on DLD device for separating cancer cells has been investigated. Specifically, we conducted force analysis and by focusing on the downstream gap distance between the posts, we improved the device which results in less cell deformation. Our developed numerical model and presented results lay the groundwork for design and fabrication of high-throughput DLD microchips for enhanced separation of CTCs.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128702761","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}

{"title":"Wind Energy Harnessing System for Low and High Wind Speeds","authors":"M. Rashidi, J. Kadambi, Renjie Ke","doi":"10.1115/imece2019-11995","DOIUrl":"https://doi.org/10.1115/imece2019-11995","url":null,"abstract":"\u0000 This work presents the design and analysis of a novel wind energy harnessing system that makes use of wind defecting structures to increase the ambient wind speed at geographic locations with relatively low wind speed. The system however reacts to highspeed wind conditions by altering the profile of the wind defecting structure in order to eliminate wind speed amplification attribute of the system, thereby protecting the wind turbine assembly at high speed wind conditions. Although increasing the wind speed is advantageous at geographic locations that the wind speed is typically low; however, from times to time, there could be sustained high-speed wind conditions at the same locations that may damage the wind turbine systems that take advantage of the wind defecting structures. The present work disclosed a wind deflecting structure formed by at least two sail-like partial cylindrical structures that are supported atop of a tower-like foundation in a symmetric arrangement, where one or more wind turbines can be installed in the space between the two partial cylinders. The two partial cylinders, each substantially in form a quarter cylinder is made of plurality of parallel ribbed-like bars, hereafter referred to as “bars” with a flexible thin material that are mechanically supported by the bars. The bars are oriented in a direction perpendicular to the ground; allowing the wing deflecting structures to accept horizonal axis or vertical axis turbines in the space between them. The function of the bars is to allow the thin material, attached to them, to assume a curved configuration substantially in the form of a quarter cylinder. The apparatus is equipped with wind speed monitoring devices, and power source and power transmission means, such as cable-pulleys, chain-sprockets, gears, or mechanical linkages that all work in concert to deploy or stow the thin material along the vertical rods depending to the magnitude of the prevailing wind speed. Preliminary computational fluid dynamics analyses have shown that the wind deflecting structure proposed here in amplifies the wind speed by a factor of 1.65.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130570304","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}

{"title":"Gas Fuel Variability Using Buffer Volume in Aeroderivative Gas Turbines","authors":"Ravinder Yerram, Balakrishnan Ponnuraj","doi":"10.1115/imece2019-11090","DOIUrl":"https://doi.org/10.1115/imece2019-11090","url":null,"abstract":"\u0000 General Electric (GE) DLE gas turbines typically use a Gas Chromatograph (GC) and/or a Wobbe Index Meter (WIM) to monitor changing fuel properties during operation. These conventional fuel sensors experience a significant time lag during operation, so a patented buffer volume device and a software algorithm is used to compensate for this lag and to ensure that the control system including metering valves can react to rapid fuel changes. Computational Fluid Dynamics (CFD) was used to design and analyze the buffer volume device that increases the time and distance taken by the gas to the metering valve. This delay provides the control system time to adjust the metering valves when the fuel transitions at the combustor to maintain gas turbine combustor stability and operation during rapid gas property changes that could otherwise result in a trip or flame-out condition. In GE’s Aeroderivative Gas Turbine Gas Fuel transfer system, the innovative buffer volume was the critical component, and this paper describes its performance in detail.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130911734","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}

{"title":"A Novel Ferrofluid-Based Valve-Less Pump","authors":"Trevor S. Michelson, Joshua Rudnick, Joshua Baxter, R. Rashidi","doi":"10.1115/imece2019-10790","DOIUrl":"https://doi.org/10.1115/imece2019-10790","url":null,"abstract":"\u0000 This paper demonstrates the development of a fluidic pump, magnetically actuated by a ferrofluid through a circular channel. The pump has a rotary design with a tangential input and output. It is designed to house a magnet to create a ferrofluid plug in one place between the inlet and outlet. There are two magnets outside of the housing attached to a rotating apparatus that move the ferrofluid around. The ferrofluid then moves around the channel, taking in and moving water through the channel towards the outlet. The pump was fabricated using a 3D printing technique. The pump was tested at three different configurations at a zero back pressure including single small moving magnet, double small moving magnet and single large moving magnet. The volumetric flow rate was measured at different rotational speeds from 9.375 rpm to 25 rpm. The highest average flow rate measured was 0.8 ml/min at 25 rpm with a single large magnet. This pump can be used for a circuit board cooling device; the pump would deliver a coolant through miniature tubes to cool the system.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131307937","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}

{"title":"Analysis of a Double Inlet Gerotor Pump: A Dynamic Multi-Phase CFD Approach Accounting for the Fluid Compressibility and Temperature Dependent Properties","authors":"M. Milani, L. Montorsi, Stefano Terzi, Gabriele Storchi, A. Lucchi","doi":"10.1115/imece2019-11482","DOIUrl":"https://doi.org/10.1115/imece2019-11482","url":null,"abstract":"\u0000 The paper analyzes the fluid dynamic performance of a double inlet Gerotor pump by means of a multi-phase and multicomponent CFD approach. The numerical simulation includes the full 3D geometry of the pump as well as the real physics of the compressible hydraulic fluid and the rotating dynamic motion. The aeration and cavitation phenomena are included in the analysis adopting the Rayleight-Plesset equation and inertia controlled growth model for bubble formation. Cavitation and aeration phenomena are detected, especially when intake pressure is lower than atmospheric pressure. The influence of the fluid temperature variation on the component performance is also numerically predicted. The accuracy of a detailed modelling of the fluid properties variation with respect to the temperature and pressure is addressed and the effects on the numerical results is investigated.\u0000 The rotational speeds of the internal and the external gears of the pump and the engagement between the teeth are addressed by means of an overset mesh approach. Constant leak height is considered between the gears and the case, while the overset mesh approach is adopted in order to accurately predict the leakage due to the teeth engagement.\u0000 This numerical approach enables to investigate the dynamic performance of Gerotor gear pumps in terms of flow rate and pressure ripples and volumetric efficiency under standard and critical (actual) operating conditions. Good agreement between numerical and experimental results was found for specific operating conditions.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125604278","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}

{"title":"Design of a High Speed Internal Gear Pump to Increase the Power Density of Electro Hydraulic Actuators (EHA) in Mobile Applications","authors":"Tobias Pietrzyk, D. Roth, G. Jacobs, Schmitz Katharina","doi":"10.1115/imece2019-10351","DOIUrl":"https://doi.org/10.1115/imece2019-10351","url":null,"abstract":"\u0000 Increasing the rotational speed of the internal gear pump entails addressing topics such as cavitation, overheating and filling problems of the tooth spaces. Besides the development of a tooth geometry and flow optimization, using CFD simulation is necessary. This paper discusses the design of the newly developed high speed internal gear pump. This includes a detailed description of the different parts as well as the dimensioning of the pump by using CFD simulations. The geometry of the pressure build-up groove has a significant effect of pressure build up inside the pump. Therefore, three different geometries are investigated. The calculation of the journal bearings for the internal gear as well as for the driving shaft is shown. To avoid cavitation problems, the suction pressure of the pump will be increased up to 25 bar. This paper will show the technical arrangements to reach this high suction pressure level whilst still using a radial shaft seal ring. In order to determine the efficiency of the newly developed high speed pump, a test rig was built up. The test rig allows the measurement of the volumetric efficiency as well as the hydraulic-mechanical efficiency at different operation points up to 10 000 rpm and 250 bar.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131556080","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}

{"title":"Effect of Phase Change Material on Temperature in a Room Fitted With a Windcatcher","authors":"P. Abdo, B. P. Huynh, Ali Braytee, Rahil Taghipour","doi":"10.1115/imece2019-10553","DOIUrl":"https://doi.org/10.1115/imece2019-10553","url":null,"abstract":"\u0000 Global warming and climate change have been considered as major challenges over the past few decades. Sustainable and renewable energy sources are nowadays needed to overcome the undesirable consequences of rapid development in the world. Phase change materials (PCM) are substances with high latent heat storage capacity which absorb or release the heat from or to the surrounding environment. They change from solid to liquid and vice versa. PCMs could be used as a passive cooling method which enhances energy efficiency in buildings. Integrating PCM with natural ventilation is investigated in this study by exploring the effect of phase change material on the temperature in a room fitted with a windcatcher. A chamber made of acrylic sheets fitted with a windcatcher is used to monitor the temperature variations. The dimensions of the chamber are 1250 × 1000 × 750 mm3. Phase change material is integrated respectively at the walls of the room, its floor and ceiling and within the windcatchers inlet channel. Temperature is measured at different locations inside the chamber. Wind is blown through the room using a fan with heating elements.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124818849","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}

{"title":"A New Approach to the Numerical Modeling of the Viscoelastic Rayleigh-Benard Convection","authors":"Xin Zheng, M. Boutaous, S. Xin, D. Siginer, Fouad Hagani, R. Knikker","doi":"10.1115/imece2019-11675","DOIUrl":"https://doi.org/10.1115/imece2019-11675","url":null,"abstract":"\u0000 A new approach to the numerical simulation of incompressible viscoelastic Rayleigh-Bénard convection in a cavity is presented. Due to the fact that the governing equations are of elliptic-hyperbolic type, a quasi-linear treatment of the hyperbolic part of the equations is proposed to overcome the strong instabilities that can be induced and is handled explicitly in time. The elliptic part related to the mass conservation and the diffusion is treated implicitly in time. The time scheme used is semi-implicit and of second order. Second-order central differencing is used throughout except for the quasi-linear part treated by third order space scheme HOUC. Incompressibility is handled by a projection method. The numerical approach is validated first through comparison with a Newtonian benchmark of Rayleigh-Bénard convection and then by comparing the results related to the convection set-up in a 2 : 1 cavity filled with an Oldroyd-B fluid. A preliminary study is also conducted for a PTT fluid and shows that PTT fluid is slightly more unstable than Oldroyd-B fluid in the configuration of Rayleigh-Bénard convection.","PeriodicalId":229616,"journal":{"name":"Volume 7: Fluids Engineering","volume":"1 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129414814","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}