Volume 10: Fluids Engineering最新文献

{"title":"Three-Dimensional Velocity and Concentration Measurements of Contaminant Release in a Scaled Urban Array","authors":"Parth Doshi, G. Fuhrman, D. Moser, Michael Benson, B.P. Van Poppel, C. Elkins, A. Banko","doi":"10.1115/imece2021-73756","DOIUrl":"https://doi.org/10.1115/imece2021-73756","url":null,"abstract":"\u0000 Turbulent atmospheric flows present many challenges to modeling the spread of pollution from manufacturing, accidental exhaust contaminants, and airborne chemical or biological attacks. Computational fluid dynamics (CFD) simulations and reduced order atmospheric dispersion models are used to predict transport and concentration of atmospheric contaminants, but these techniques require validation against experimental data sets. The present work applies magnetic resonance (MR) techniques to measure contaminant flows in an urban array to generate robust data sets for model validation. Magnetic resonance velocimetry (MRV) and concentration (MRC) methods were employed to generate time-averaged, three-dimensional, three-component velocity field and concentration data sets at sub-millimeter resolution — a volume of data far greater than can be measured in large-scale field tests. A scaled urban array comprising 13 buildings at an angle of 26.2° relative to the incoming flow was placed in a water channel test section within an MRI system. A dilute aqueous solution of copper sulfate (CuSO4) was used as the working fluid to achieve a Reynolds number of 20,000 based on the test section’s hydraulic diameter. The test section design included a roughness section to ensure turbulent flow within the scan volume; two vertical injectors created plume-plume and plume-building interactions at a blowing ratio of 0.6. This work is the first of its kind to employ dual injection and buildings oriented at angles other than 90° or 45° to the main flow. Contaminant concentrations of 0.0125M, 0.0625M, and 0.3M were used and the data combined to increase the signal-to-noise ratio in regions of low concentration. Results illustrate flow and concentration details near building wake regions, injector plume mixing, the influence of building blockage on velocity gradients and concentration penetration, and contaminant flux throughout the flow region. Measurement uncertainty was estimated to be approximately ±5% for velocity and ±5% for concentration.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128280895","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":"Theoretical Characterization of Liquid Sloshing in Containers","authors":"S. Karthick, V. Satish","doi":"10.1115/imece2021-70152","DOIUrl":"https://doi.org/10.1115/imece2021-70152","url":null,"abstract":"\u0000 This paper theoretically characterizes the sloshing phenomena at the free liquid surface in partially or filled stationary containers based on the analogy with surface gravity waves. The oscillations of the liquid surface and the associated dynamics of the liquid-air interface results in interfacial wave displacement of two types progressive (in-phase) and standing (out of phase) modes. This study involves a rectangular stationary fluid tank partially filled with the tested fluids and subjected to the dominant progressive wave at the liquid-air interface. The sloshing strength is decided based on the temporal progression of the generated wave spectrum obtained utilizing small-amplitude wave theory and linear stability analysis in combination. The expressions for determining the angular frequency, the phase speed, and the corresponding temporal growth rate of the progressive disturbances is derived. The tested fluids include standard liquid water and commercially preferable fluids ethylene glycol and glycerol. This model developed based on the irrotationality of fluid motion neglects the viscous influence and comprises the gravity and the surface tension mimicking a practical scenario. Utilizing deep-water assumptions, the effect of surface tension has been determined for wavenumbers in the range of 490–1250 rad/m. The independent evolution demonstrates the influence of surface tension on the temporal growth rate. Water with the maximum surface tension has a higher growth rate than a low surface tension fluid ethylene glycol among the tested fluids. The effect of surface tension is to escalate the temporal growth rate leading to instability and increased liquid sloshing rate.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128821058","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":"Applications of Electrochemical Impedance Spectroscopy (EIS) for Various Electrode Pattern in a Microfluidic Channel With Different Electrolyte Solutions","authors":"Shanzid Kabir, Dipannita Ghosh, Nazmul Islam","doi":"10.1115/imece2021-70623","DOIUrl":"https://doi.org/10.1115/imece2021-70623","url":null,"abstract":"\u0000 Electrochemical impedance spectroscopy (EIS) is a rapidly developing technique in microfluidics for characterizing materials and interfaces. By using equivalent circuits as models, it can determine the electrical properties of heterogeneous systems like membranes or electrolytes in a microfluidics chamber. For measuring Impedance spectroscopy, a small amount of perturbing sinusoidal signal was applied to the electrochemical microfluidic cell and measured the resulting current response. Two main ways to visualize EIS are Nyquist and Bode plot. In our research, both of these plots describe the characteristics of the electrochemical system in their ways. In our studies, we analyzed both the Bode plot and Nyquist plot for two different electrodes arrangement named as T shaped electrode (or orthogonal electrode) and V-shaped electrodes. We also compare these electrodes in three different electrolytes DI water (18.72μS/cm), tap water (666.12 μS/cm) and PBS 1× (8235.24 μS/cm) with three different ranges of conductivity to observe their characteristics changes and to compare them. We analyze the capacitive effect or electric double layer (EDL) effect for the electrode and electrolyte interface and how electron transfer kinetics and diffusional characteristics affect the spectra. As Impedance takes into account all factors such as capacitance, resistance or inductance besides the ideal resistor, it can define the characteristics of each different cell or electrode pattern by the spectra. For our microfluidics system, the capacitive systems are traditionally very large especially at the low frequencies because of impedance. The purpose of this research is to find the optimal operating range for different AC electrokinetic mechanism.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114367472","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":"Wear Analysis of a Ni-Resist 1 Mixed Flow, Multi-Stage Centrifugal Pump: An Erosion-Corrosion Case Study","authors":"Carla Naiana Pires da Silva","doi":"10.1115/imece2021-66653","DOIUrl":"https://doi.org/10.1115/imece2021-66653","url":null,"abstract":"\u0000 One of the most used secondary recovery methods in mature oil production fields is the injection of water. Multi-stage mixed flow centrifugal pumps are usually used in order to achieve the required high pressures and flow rates. However, the material of this equipment can suffer high damage when it is in contact with the chemical complexity of the reservoirs water.\u0000 This paper proposes a case study referring to the effects of erosion-corrosion in an injection pump that operated in an oil production company in mature fields located in Brazil for six months. The equipment has its rotors and diffusers manufactured in Ni-Resist 1.\u0000 Initially, twelve samples of the water were collected at two different points and several components were analyzed, among them we can highlight the salinity tests that showed an average value of 40.36% measured in the suction of the pump and the suspended solids that presented an average value of 236.58 mg/L which is a value considered high for the operation of this equipment.\u0000 Continuing the study, the equipment was teared down and a visual inspection of all 41 stages was done. In this analysis, it was possible to identify an excessive wear and the damage form. The diffusers showed a mass loss at the blades leading edges, in the sealing region and in the coupling region between stages and it kept the blades rear edges in good condition. The impeller showed excessive wear, losing mostly of the blades and 100% of the skirt, the hydraulic balancing holes showed little wear on their edges.\u0000 After visual inspection, micrography and chemical analysis by Optical Emission Spectrometry (OES) were performed reaching values consistent with the Nickel Institute, thus not affecting the type of damage.\u0000 In the semi-quantitative chemical analysis by Energy Dispersive Spectrometry (EDS) we were able to evaluate the distribution of the main elements in the base metal and in the impeller decomposition residues.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132713560","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":"Fabrication of Heterogeneous Hydrogel Models for Convection-Enhanced Drug Delivery Studies","authors":"Haipeng Zhang, Aidan Johnson, Sangjin Ryu, S. Kim, Chi (Kevin) Zhang","doi":"10.1115/imece2021-67615","DOIUrl":"https://doi.org/10.1115/imece2021-67615","url":null,"abstract":"\u0000 Convection-enhanced drug delivery (CED) enables faster convective dispersion of drug molecules through soft, porous tissues than diffusion, which is beneficial for treating aggressive tumors. Advancing the CED technology requires rigorous characterization of fluid transport through soft, porous tissues. When a fluid flows through soft, porous tissues, the deformation and/or structural rearrangement of the hosting solid alters the pattern and efficiency of fluid propagation. Such hydro-mechanical coupling can be understood by experimentally studying fluid flows through hydrogel phantoms that mimic soft, porous tissues in vitro. However, current studies using hydrogel-based models are limited because homogenous hydrogel models with uniform properties have been employed. To overcome this limitation, we aim to develop heterogeneous hydrogel models for CED studies by embedding agar beads (1 w/v%) in an agarose gel block (0.2 or 0.6 w/v%), and this paper introduces our fabrication method in detail.\u0000 The fabrication process includes two steps: fabrication of the gel beads and dispensing the gel beads in the agarose gel. In the first step, agar gel beads were fabricated with the rotating-liquid-based drop generation method. Hot agar gel solution (∼95°C) was injected through a syringe needle with its tip immersed in cold mineral oil (∼4°C) that rotates in rigid body motion. As agar gel solution drops were sheared off from the needle tip by the bulk mineral oil motion, they became spherical due to surface tension. While falling through the mineral oil, the gel drops were cooled and became gel beads. These agar gel beads were harvested, washed in water, and stored at 4°C. Microscopy imaging of the created gel beads confirmed that the sizes of the beads were uniform. In the second step of fabrication, agarose solution was prepared at 95°C, and the precooled agar beads were mixed in the agarose solution. Then, the mixture was poured into a precooled mold (a petri dish at −20°C), and then the mold was moved into a refrigerator immediately for quick cooling and gelation. Microscopy imaging of the embedded gel beads showed two heterogeneous agarose gel blocks with embedded agar beads were produced with different sized agar gel beads, different concentration of agarose gel, and different distribution of agar gel beads in agarose gel.\u0000 The presented method has the following advantages. First, the size of agar beads can be adjusted by changing the injection speed of the agar solution and the rotation speed of the mineral oil. Second, the level of heterogeneity can be modulated by changing the properties of the gel beads and block and by adjusting the volume fraction between the gel beads and the gel block. Also, it is expected that the degree of fusion between the gel beads and the gel block could be controlled by adjusting the temperature of the agar gel beads and the agarose solution, and the cooling process of their mixture. Therefore, the suggested heterogene","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"525 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116337447","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":"Computational Fluid Dynamics Modeling and Experimental Testing of Hydraulic Spool Valves","authors":"Kyle Janosky, Maryam Younessi Sinaki, Bipin Kashid","doi":"10.1115/imece2021-72697","DOIUrl":"https://doi.org/10.1115/imece2021-72697","url":null,"abstract":"\u0000 To have faster time to market one must reduce the required experiments needed to develop new products. In this paper, hydraulic spool valves were investigated and a comparison of actual experimental data to the results of Fluent simulation was made. This comparison included multiple standard turbulence models in addition to a custom version of GEKO k-omega. Along with turbulence models, different solver options were compared to evaluate their impact on the results. This data will help better correlate future simulations to experimental data, thus utilizing simulation to design and experiment to verify the final solution if required.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121856859","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":"Aerodynamic Performance Analysis of Winglets of Modern Sailplanes","authors":"Jens Kästner, P. Epple, M. Steppert","doi":"10.1115/imece2021-69672","DOIUrl":"https://doi.org/10.1115/imece2021-69672","url":null,"abstract":"\u0000 In this work the aerodynamic performance of winglets of modern sailplanes were investigated. First isolated wings with winglets were designed and investigated and compared to the wings without winglets, showing the fundamental working principle and effectiveness of winglets. Then a complete sailplane was designed with an integrated inviscid flow method with XFLR5 [1] combined with Navier-Stokes CFD with Siemens PLM STAR CCM+ computations. In such a way a modern sailplane was designed for operation with winglets. Using this modern sailplane design the impact of winglets on sailplanes was investigated in detail. This modern sailplane was simulated with CFD in the configurations without winglets and with two modern advanced winglets and their aerodynamic characteristics and performance were investigated and compared. All aerodynamic results are analyzed and shown in detail.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"462 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116778974","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":"Digital Feed-Forward Gas Flow Rate Control With a Switched Nozzle Valve","authors":"Christopher R. Martin, T. Batzel, Ethan H. Liebmann","doi":"10.1115/imece2021-70549","DOIUrl":"https://doi.org/10.1115/imece2021-70549","url":null,"abstract":"\u0000 This work presents the (SNV) approach for feed-forward gas flow rate control, the considerations included in the design of a prototype, and the results of its evaluation using a bell prover. The SNV uses a pulse-width modulation approach to provide inexpensive feed-forward gas flow rate control in contrast to closed-loop systems with thermal mass flow sensors. Attempts for feed-forward digital control of gas flow rate with throttling is usually frustrated by the difficulty of precisely and repeatably locating a throttle body to the precision required. The SNV uses a statically machined transonic nozzle to provide a mass flow rate insensitive to back-pressure for the on portion of the switching cycle. The severe pressure drop usually associated with sonic flow is almost entirely recovered by using a converging-diverging nozzle instead of a plain orifice, so that excellent metering can be achieved with drops as low as 11%.\u0000 Uncertainty in the actual delivered flow is found to be ±1% of full scale. Back-pressure insensitivity is found to be ±0.5% up to 88% of the supply pressure. The operator design predicted that operation would be possible up to 100Hz, but actual performance was limited to roughly 33Hz. Unexpected minor quadratic behavior in the valve calibration and a single errant data suggest that the degraded performance is due to migration of lubricant inside the assembly.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"305 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122243380","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":"Experimental Study of Gas-Liquid Displacement in a Porous Media Microchip by Digital Image Analysis Method","authors":"Shuo Yang, G. Kong, Zan Wu","doi":"10.1115/imece2021-69902","DOIUrl":"https://doi.org/10.1115/imece2021-69902","url":null,"abstract":"\u0000 Gas-liquid displacement is still a complex and challenging topic in the field of nonequilibrium physics and many industrial applications. In this study, pore-scale displacement of gas-liquid flow in a porous medium was investigated. A digital image analysis method was used to process the images captured by a high-speed camera. The invasion pattern demonstrated that an increase in viscosity of the displaced liquid tends to decrease the finger width and the number of fingers. The effect of liquid viscosity on the invasion velocity was also investigated. The invasion velocity changes monotonously with the viscosity, showing an opposite trend at high and low gas flow rates, which is attributed to the viscous resistance of the liquid phase and the mass balance of the gas phase. Then the invasion area was measured and the N2 displacement ratio was used to estimate the injection efficiency. The displacement ratio decreases with the increase of liquid viscosity and gas flow rate. Finally, the invasion dynamics was studied. It revealed that the gas tip moves in a stepwise way, i.e., the tip goes forward, and then it stays there for a while and then goes forward again. The gas tip splits and expands in side directions and also moves backward when the gas pressure is not high enough to overcome the forward capillary pressure, which can be found for all the displaced liquids in this study.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122363908","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":"Effects of Combined Electromagnetic and Bottom-Plug Stirring in a Steel Refining Ladle","authors":"J. Godinez, N. Walla, Xipeng Guo, Chenn Q. Zhou","doi":"10.1115/imece2021-71767","DOIUrl":"https://doi.org/10.1115/imece2021-71767","url":null,"abstract":"\u0000 After being tapped from a basic oxygen furnace or electric arc furnace, the liquid steel must be refined at a ladle treatment station as part of alloying and quality improvement. In the ladle, the steel can be stirred using electromagnetic techniques, argon injection, or a combination of both methods. This work discusses the observed differences in stirring characteristics between these different approaches. Simulations of gas-stirring using a single plug, stirring using upwards electromagnetic stirring (EMS), downwards EMS, and the combination of electromagnetic stirring and single bottom plug with various plug positions in relation to the active EMS unit. The approach found in this work uses the CFD solver ANSYS Fluent to the simulate the isothermal multiphase flow field using a combined Eulerian and Lagrangian (E-L) approaches. The E-L approach with DPM uses a time-step (ts) of 1e−3s while the mixing study uses a ts of 0.1s.\u0000 To improve simulation stability and computational speed, the Lorentz forces of the magnetic field data are imported directly into the simulation via User Defined Function and applied as a momentum source term onto the liquid steel. The flow field is monitored for quasi-steady state, upon which the momentum calculation is disabled and the secondary mixing study begins. The mixing study uses a tracer species to determine how long is required until homogeneity is reached. It was found that under standard stirring conditions, EMS has a faster mixing time than EM-Gas and gas-only, though both EMS and EM-gas see greater wall shear stresses.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131806810","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}