Volume 10: Fluids Engineering最新文献

{"title":"Experimental Investigation of Multi-Component Emulsion Fuel Stability","authors":"Nicholas Hentges, A. S. M. S. Parveg, A. Ratner","doi":"10.1115/imece2021-70105","DOIUrl":"https://doi.org/10.1115/imece2021-70105","url":null,"abstract":"\u0000 The emulsification of water with liquid fuels to modify combustion characteristics has been of great interest to the combustion research community for some time. The emulsions are usually comprised of only water combined via ultrasonification (or other mechanical methods) with a base hydrocarbon fuel. These emulsions show improved combustion characteristics, such as lower combustion temperatures, and lower emissions. One of the main issues with these emulsions, however, is that these emulsions are not stable and are prone to phase separation over time, which inhibit the economic viability and practical application of these fuels. There are a multitude of ways being researched to improve fluid stability, including new mixing techniques, the addition of nanoparticles, as well as the addition of other fluids. The addition of ethanol to water-based emulsions has been shown to decrease the size of water droplets in the emulsion, allowing for a more homogenous mixture. With the aviation industry being a sizeable source of the global emissions caused by transportation, methods of lowering the emissions of aviation fuels as well as greener alternatives are needed. Present research quantitatively studies how the addition of ethanol to water and jet fuel emulsions affects the stability of the emulsion. A non-invasive, quantitative, and economical method for determining phase separation is used to study the stability of these multi-component mixtures. The system periodically measures the phase separation of the fluid column by automatically shining light through the fluid and detecting how much interference is created by the fluid. The system does this at five different depths of the fluid so the phase separation of the emulsion can be tracked in more detail. Ethanol and water are studied at mixtures of 5%, 10%, 15%, and 20% ethanol by weight and 5% and 10% water by weight emulsified with jet fuel. It is expected that the present research will lay additional foundation for the future study of fuel emulsion stability, as well as spark additional interest in utilizing emulsions to improve fuels.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"254 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":"132495151","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":"Development of a Topology Optimization Framework For Cooling Channel Design in Die Casting Molds","authors":"F. Navah, Marc-Étienne Lamarche-Gagnon, F. Ilinca, M. Audet, Marjan Molavi-Zarandi, Vincent Raymond","doi":"10.1115/imece2021-73363","DOIUrl":"https://doi.org/10.1115/imece2021-73363","url":null,"abstract":"\u0000 This work is concerned with the development of a framework for the efficient design of cooling channels via two different topology optimization paradigms: a diffuse and a sharp. Each approach relies on a distinct thermo-fluid modeling and features a specific material distribution mode, i.e. fraction-based (diffuse) versus interface-based (sharp). The two models are described and the corresponding solvers are validated. A gradient-based optimization methodology is adopted and the details of the adjoint-based gradient computation are introduced. Finally, examples of cooling channel design optimization are presented and discussed.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"45 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":"129228907","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 HVAC Settings and Windows Open or Close on the SARS-CoV-2 Virus Transmission Inside a Mass Transit System Bus","authors":"M. Zafar, Vincent Lee, W. Timms, Patrick Bounds, M. Uddin","doi":"10.1115/imece2021-71701","DOIUrl":"https://doi.org/10.1115/imece2021-71701","url":null,"abstract":"\u0000 With the current outbreak of SARS-CoV-2, public transportation is a key area which must be investigated to ensure both passenger safety and efficiency of passenger transport to best serve the community and reduce environmental footprint. In this paper, the transport of the SARS-CoV-2 virus through human respiratory particles is examined using transient Computational Fluid Dynamics (CFD) simulations to determine the impacts different ventilation configurations on the probability of viral exposure. The motion of the viral particles was simulated first by solving for the flow field inside the bus using a proprietary Navier-Stokes finite-volume solver, RavenCFD by Corvid Technologies, and then using Lagrangian particle tracking (LPT) post processing techniques. The LPT methods used allowed for the injection of respiratory particles, according to distributions found in literature, which included sneezing, coughing, and speaking. To fully investigate the problem space the moving bus was modeled with the windows in various states of closure and with various HVAC configurations. In all scenarios, a volumetric Viral Mean Exposure Time (VMET), which considers the viral load calculations, was used to quantify the various exposure risk of all passengers on the bus. It was found that the most efficient ventilation system on a public transport bus was to keep the windows closed and HVAC of main cabin at maximum to minimize the viral exposure within the bus.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"15 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":"121184369","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":"Performance Characterization of Hollow Fiber Direct Contact Membrane Distillation Module","authors":"Jaber M. Asiri, Abdulaziz M. Alasiri, Justin Caspar, Guanyang Xue, A. Oztekin","doi":"10.1115/imece2021-70229","DOIUrl":"https://doi.org/10.1115/imece2021-70229","url":null,"abstract":"\u0000 Computational fluid dynamics (CFD) simulations were carried out to study the performance of a single hollow fiber in a direct contact membrane distillation (HF-DCMD) module for a desalination process. The feed solution is seawater with a salt (NaCl) concentration of 35 g/L. The Navier-Stokes, mass and energy transport equations are considered, with a coupled boundary condition imposed by the membrane. The system is investigated to examine sensitivity toward the membrane thickness, pore size, and inner hollow fiber diameter based on existing commercial fibers. Two membrane thicknesses (300 μm, 500 μm), two membrane pores sizes (0.2 μm, 0.45 μm), and two inner diameters (1.2 mm, 1.8 mm) are studied in the laminar regime at fixed operating conditions. The presence of temperature polarization causes a significant drop in the water permeation in the DCMD system due to reduced driving force across the membrane. The characterization of polarization inside the hollow fiber will be the focus of this work. It was found that the vapor flux was most sensitive to the membrane thickness (a 30% flux increase) versus the inner diameter (2% flux increase). The pore size is also a very influential parameter (20% flux increase), moving from optimal to less-optimal properties.","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":"131106804","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 Single and Multiple Protuberances on the Aerodynamic Performance of a Wind Turbine Blade","authors":"Archit Bapat, P. Salunkhe, Mahesh K. Varpe","doi":"10.1115/imece2021-69763","DOIUrl":"https://doi.org/10.1115/imece2021-69763","url":null,"abstract":"\u0000 Wind energy currently contributes to nearly 5% of our global electricity production and plays a vital role amongst other renewable energy resources. This work aims to numerically investigate the aerodynamic performance of a NACA 634-021 blade with single and multiple spanwise leading-edge protuberances. Different configurations of protuberances viz. continuous and equally spaced intermittent profiles are evaluated for aerodynamic performance. The numerical simulations showed that stall onset is preponed by the protuberance, however, the performance is improved in the post-stall regime. At 27° angle of attack, the continuous protuberances led to the performance improvement of 44%, whereas intermittent protuberances enhanced the blade performance by 37%. Negligible improvement was observed with a single protuberance. Subsequent studies demonstrated that the formation of counter-rotating vortex pair and their interaction with the retarding boundary layer imparts much-needed momentum and plays a significant role in controlling the stall inception. At higher post-stall angle of attack, the continuous protuberances supersede all other cases.","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":"129046663","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":"Hydrokinetic Turbine Performance and Wake Analysis Using a Data-Driven Actuator Line Model","authors":"J. Bowman, S. Bhushan, G. Burgreen, I. Dettwiller","doi":"10.1115/imece2021-71957","DOIUrl":"https://doi.org/10.1115/imece2021-71957","url":null,"abstract":"\u0000 A data-driven actuator line model was derived using a blade-resolved turbine DES simulation. Pressure and viscous forces were extracted from the blades and incorporated into an actuator line model framework implementation in OpenFOAM. The data-driven actuator line model attempts to address the limitations of the currently available actuator line model. The development of the data-driven actuator line model transformed the high-fidelity blade-resolved force data into force coefficients. The result is a finely tuned model that can replicate the turbine performance of the blade-resolved model for a fraction of the computational expense. The comparison between the data-driven actuator line model and the actuator line model reveals that at high tip speed ratios the actuator line model over predicts the thrust and power coefficient. The author discusses the limitations of the data-driven actuator line model in its current form and how the model will be advanced.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"83 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113967428","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":"Microfluidics-Based Fabrication of a Hele-Shaw Cell Device for Drop Coalescence Imaging","authors":"Carson Emeigh, Haipeng Zhang, Sangjin Ryu","doi":"10.1115/imece2021-68063","DOIUrl":"https://doi.org/10.1115/imece2021-68063","url":null,"abstract":"\u0000 The Hele-Shaw cell has been well used for various flow studies because it can simplify analyzing the flow of interest to two-dimensional creeping one. The Hele-Shaw cell consists of two parallel flat plates with a very small gap between them. When a working fluid is injected through this narrow gap, two-dimensional Stokes flow is generated with an extremely low Reynolds number and negligible flow velocity normal to the plates.\u0000 Applications of Hele-Shaw cell devices include experimental studies of drop coalescence, Stokes flow, and confining cells to a 2D plane, and they usually depend on cameras to capture phenomena of interest from the experiment. The quality of the collected images largely depends on the optical quality of the Hele-Shaw cell. Therefore, it is favorable to reduce the degree of light attenuation through Hele-Shaw cells.\u0000 Previously we fabricated a Hele-Shaw cell using polydimethylsiloxane (PDMS) and soft lithography, which are common in microfluidic fabrication, to study drop coalescence with high-speed imaging. It was found that the frame rate of high-speed imaging was limited by light intensity, which was affected by light attenuation through PDMS, and thus the very initial stage of the neck growth during coalescence was not captured. To overcome this limitation, an advanced fabrication method of the Hele-Shaw cell has been developed to incorporate a glass observation window in the PDMS part of the cell.\u0000 The previous and newly developed Hele-Shaw cell devices were compared in terms of local intensity and contrast, and improvement in image quality was confirmed. Our method has the following advantages. First, the thickness of the PDMS layers is controllable and thus the attenuation of light intensity can be reduced. Second, the glass-based observation window can enable clearer images with reduced image defects caused by PDMS. Therefore, the suggested microfluidics-based fabrication method of the Hele-Shaw cell has the potential to increase the resolution of high-speed imaging and to reduce the difficulty of post image processing.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"12 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":"116879596","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 Valve Closure Time on Water Hammer","authors":"William A. Davies, M. Wolf, Michael Barry, S. O'Hern, Tim Morse","doi":"10.1115/imece2021-71153","DOIUrl":"https://doi.org/10.1115/imece2021-71153","url":null,"abstract":"\u0000 Water hammer is a phenomenon that can cause failure in many different fluid systems, including residential water systems, municipal water distribution systems, oil and gas applications, power plants, and chemical processing systems. By understanding the magnitude of the pressure increase that may develop as a result of different system operating conditions, an engineer can better assess the risks of failure and/or the causes of a failure that has already occurred. In this study, an experimental setup at the scale of a residential water system is used to measure the pressure rise generated when varying the fluid velocity and duration of valve closure time. Comparisons are made between the measured pressure values and the estimated pressure values from existing classical models on fluid velocity and valve closure time with respect to water hammer. While the underlying trends of the classical theory are observed in the experiments, a discussion of the notable deviations from theory is presented, along with other considerations that are relevant to measurements in a specific physical system. This study also provides a comparison between the measured results and the standards and methods that are commonly relied upon for certification of plumbing fixtures as required by building codes such as the International Plumbing Code or Uniform Plumbing Code.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"113 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":"115156454","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 and Computational Study of Direct Contact Membrane Distillation","authors":"Deliya Kim, Justin Caspar, C. Romero, S. Neti, A. Oztekin","doi":"10.1115/imece2021-70455","DOIUrl":"https://doi.org/10.1115/imece2021-70455","url":null,"abstract":"\u0000 Experimental and computational studies of direct contact membrane distillation (DCMD) are conducted. The permeate flux is measured in a module containing a flat sheet membrane. Polytetrafluoroethylene (PTFE) hydrophobic membrane (Membrane Solutions, FPB045A16) with a nominal pore size of 0.45 μm, the thickness of 179∼239 μm, the porosity of 80% is used in the experiments. The feed solution is a binary mixture of water and NaCl. The inlet feed temperature is fixed at 70°C, and the feed Reynolds number is varied between 500 and 2000. Two inlet feed concentrations, 0 and 35g/L, are considered. The permeate flow rate was kept constant at Re of 1300 and temperature of 20°C. Three-dimensional steady-state computational fluid dynamics (CFD) simulations are performed using the laminar model. The Navier’s Stokes, energy, and mass transport equations in each channel coupled with flux boundary conditions imposed at the membrane surface are solved. The predicted module-averaged flux is compared to measured data for all operating conditions. Measured and predicted flux agrees well; validating both experiments and model, Temperature polarization in the feed and permeate channel and concentration polarization in the feed channel are characterized by validated CFD simulations.","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":"125846009","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":"Investigating the Flow Field Physics Within Unsteady Compressible Flows","authors":"Dehua Feng, Yang Gao, Larry W. Thompson, F. Ferguson","doi":"10.1115/imece2021-71788","DOIUrl":"https://doi.org/10.1115/imece2021-71788","url":null,"abstract":"\u0000 Computational Fluid Dynamics (CFD) continues to play a critical role in the solution of complex fluid dynamics flows. This computational tool allows us to investigate complex flow patterns that would otherwise be impossible to investigate and has greatly aided in the development of our knowledgebase. At the Heart of successful CFD tools are creative numerical schemes that are developed and used in an attempt to capture ‘real world’ flow physics. One such creative numerical scheme in the Integro-Differential Scheme (IDS) has be created. In previous studies, the IDS Scheme has demonstrated that it has achieved adequate dispersion and dissipation capabilities in the smooth flow field regions along with very robust shock-capturing capabilities in the vicinity of discontinuities. In this proposed paper, the IDS Scheme will focus on unsteady fluid motion like Rayleigh-Taylor Instability problem as an example with 2nd order accuracy in space and 3rd order of accuracy in time. Initial perturbations will lead to bubbles and mushroom-shaped spikes due to the release of potential energy, which is from a linear growth phase into a non-linear growth phase. The Total Variation Diminishing Runge-Kutta (TVD-RK3) Scheme will be applied in IDS Scheme and shows incredible results. The detail of how eddies are formatting and interact will be proposed in this paper. Also, IDS Scheme shows its capability to capture more eddies which WENO 5th order is not shown with same computational grids. The IDS simulations are governed by the full set of Navier-Stokes Equations (NES) and focus on the basic flow structure and their interaction which lead to complex flow phenomena. The numerical form of the IDS to be used for solving these compressible flow field problems will consist of the coupled 3rd order Runge-Kutta explicit time marching method and an explicit spatial integral method for the control volume convective flux evaluation. The accuracy and resolution of the unsteady IDS scheme will be tested by its simulations of several benchmark unsteady compressible test cases. Already, evidence of the IDS capability is demonstrated in its simulating solution of the unsteady Rayleigh-Taylor problem.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"33 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":"125023656","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}