Volume 10: Fluids Engineering最新文献

{"title":"Numerical Simulation of Moisture-Heat Coupling in the Drying Process of a Multi-Temperature Zone Belt Dryer","authors":"Hepeng Jia, Kai Wu, Yu Wang, Yu Sun","doi":"10.1115/IMECE2020-23267","DOIUrl":"https://doi.org/10.1115/IMECE2020-23267","url":null,"abstract":"\u0000 The multi-temperature zone distributed drying method solves the problem of uneven drying of the conventional belt dryer. Multi-temperature zone belt dryer is widely used in the drying of aquatic feed products. This paper presents a numerical simulation method for multi-temperature zone belt dryer. The computational fluid dynamics (CFD) was applied to simulate the drying process of materials in a multi-temperature zone belt dryer. The user-defined function (UDF) was used to study the moisture-heat coupling drying process to predict the airflow filed of the multi-temperature zone belt dryer. The results showed that there were vortexes in each drying chamber so that airflow velocity distribution of the material layer was not uniform. However, the multi-temperature zone distributed drying method can maximize the drying efficiency through the bilateral distribution of the air inlet. The temperature distribution in each temperature zone was relatively uniform, and the temperature difference between the two sides of the feed layer was massive. The moisture content of the materials in each temperature zone was very uniform, the drying unevenness was less than 1.0%, and the dryer has excellent moisture content uniformity.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131391411","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":"Optimization of Nodule and Height Sizes for Mixed Hydrophilic and Hydrophobic Surfaces","authors":"Brian Frymyer, A. Oztekin","doi":"10.1115/IMECE2020-23470","DOIUrl":"https://doi.org/10.1115/IMECE2020-23470","url":null,"abstract":"\u0000 Patterned surfaces of hydrophobic and hydrophilic materials are considered to sustain dropwise condensation, providing the benefits of both materials and creating a surface with a low energy barrier for nucleation and capable of sustaining dropwise condensation. Surface heights, nodule sizes, and flow rates are evaluated on square-patterned surfaces to maximize mass collection. A thermal model is used to assess surface performance and includes an equivalent thermal resistance for diffusion. Flow rates of 15, 25, 50, and 100 m/s with nodule sizes between 0.1 mm to 3.6 mm are evaluated. Surface heights of 0.25, 0.5, 1, and 2 m are also assessed. For flow rates greater than 50 m/s, turbulent flow optimum nodule size is between 0.2 mm and 0.6 mm. Surfaces greater than 1 m in height at flow rates less than 50 m/s maximize mass with nodule sizes of 1.4 mm and 2 mm.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"517 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133366622","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":"Numerical Study of the Effects of Confined Airfoils Usage in High Bypass Ratio Turbofan Engines","authors":"R. Aguilar, Cesar Celis, Marcio Pontes","doi":"10.1115/IMECE2020-24196","DOIUrl":"https://doi.org/10.1115/IMECE2020-24196","url":null,"abstract":"\u0000 Turbofan engines are the main power plants used in the commercial airline industry. Increasing the bypass ratio (BPR) in turbofan engines enhances their propulsive efficiency and reduces both noise and harmful gas emissions. Over the years the aero engine industry has devoted huge efforts and enormous amounts of money to improve turbofans’ propulsive efficiency through the increase of their BPR. Based on the current technology however, there is a practical limit to how much BPR can be increased before significant penalties associated with increased both engine weight and nacelle drag erode the benefits. This work numerically studies thus the benefits of using confined airfoils in the engine bypass flow region to counteract the turbofan engine weight and alleviate the efforts over the aircraft wing structure. Accordingly, a description of the proposed engine-airfoils arrangement, relative dimensions and airfoils adequate placement inside the engine bypass duct is initially presented. Two different flight conditions, take-off and cruise, are numerically assessed next using computational fluid dynamics (CFD) based approaches to characterize the particular bypass flow behavior. The numerical work includes the study of engine configurations similar to those used in long-range aircraft. A structured multi-domain mesh, in conjunction with both Reynolds-average Navier Stokes (RANS) and steady-state mixing planes approaches, are used in the numerical model utilized. The main results indicate that using confined airfoils produces substantial lift respect to the engine weight. Engine weight reductions of up to 23% are observed because of the use of confined airfoils in the engines bypass ducts.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115315602","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":"Analytical and Numerical Investigation of the Fluid Structure Interaction of an Elastic Beam in a Water Channel","authors":"M. Fritsche, P. Epple, Antonio Delgado","doi":"10.1115/IMECE2020-23831","DOIUrl":"https://doi.org/10.1115/IMECE2020-23831","url":null,"abstract":"\u0000 The interaction between fluids and solids is becoming increasingly important in the design and analysis of machines, buildings and systems. Due to the fluid-mechanical phenomenon of turbulence and the associated flow and vortex shedding, the fluid structure interaction must be considered, for example, in aircraft wings, civil engineering (e. g. television towers or bridges), the rotor blades of wind turbines or in the field of sensor technology. Due to the increasing computing power, increasingly complex tasks can be calculated with the help of numerical simulations.\u0000 In this paper, an elastic beam has been defined as test case and has been analyzed in different ways with the methods of the fluid structure interaction (FSI), i.e. with analytical and numerical approaches. For this purpose, the plastic beam has been fixed on one side in a water channel and the flow around it and the beam deflection have been measured. The deformation of the beam due to the flow load around it has been analyzed for varied flow velocities.\u0000 First, the beam deformation has been estimated based on the analytical equations from structural mechanics and an assumed stagnation pressure on the beam surface. Additionally, the drag coefficient from experimental data of the literature was used to estimate the force on and the bending of the beam. Then two numerical simulations with different FSI coupling methods have been performed with Ansys Workbench 2020 R1. On the one hand, a one-way coupling analysis has been performed in which the pressure field was calculated from the CFD simulation and then transferred to the mechanical analysis. On the other hand, a two-way coupling computation has been performed, which also takes transient effects into account. For this purpose, the flow field and the pressure field have been exchanged iteratively between the fluid and the mechanical solver. This coupling approach is general and corresponds to reality since large deformations and non-linearities are considered. However, this approach always requires a very computation intensive, non-stationary calculation.\u0000 The results obtained from these parameter studies have then been evaluated and compared in order to determine the accuracy of each analysis methodology. The elaborated results have been discussed and analyzed in detail.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123361277","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":"Numerical and Experimental Analysis of a Novel Concept for Axels Dry Braking System in Off-Road Vehicles","authors":"M. Milani, L. Montorsi, G. Muzzioli, Gabriele Storchi, Stefano Terzi, P. Rinaldi, Matteo Stefani","doi":"10.1115/IMECE2020-23703","DOIUrl":"https://doi.org/10.1115/IMECE2020-23703","url":null,"abstract":"\u0000 The paper proposes a novel concept for axels dry braking system in off-road vehicles by implementing an oil recovery system in the friction plates chamber. The new system is able to remove the oil in the discs’ chamber when they are not engaged and to replenish it when the braking system is activated and the heat generated has to be dissipated. Thus, the energy losses due to the oil splashing will be significantly reduced with remarkable effects on the fuel consumption of the vehicle. Since experimental measurements are very difficult to carry out on a real system, a simplified geometry is designed and an ad-hoc test rig realized. Fast imaging techniques are used to capture the multiphase flow pattern within the friction plates chamber at different rotational speeds of the axel. The experimental results are used to validate a full 3D multi-phase CFD approach. A good agreement between the measurements and the calculations is found.\u0000 The numerical modeling is therefore employed to predict the flow distribution in the real geometry and under actual operating conditions. A modular approach is adopted for the domain subdivision in order to represent accurately the three dimensional geometrical features, while the volume of fluid approach is used to model the multi-phase flow that characterizes the component. A conjugate heat transfer model is also adopted to predict the heat transferred from the discs to the working fluid and how the fluid is dissipating the heat within the component. By means of the numerical analysis the geometry of the real system is designed in order to improve the performance of the dry braking systems both in terms of energy saving and oil cooling.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"184 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114958548","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":"Particle Transport Coefficient (PTC) and Phase-Efficiency Diagram: A New Perspective to Evaluate Three-Phase Particle-Laden Flow","authors":"Zhifeng Zhang, A. Pruvot, Pablo Cisternas, J. Mcandrew","doi":"10.1115/IMECE2020-23888","DOIUrl":"https://doi.org/10.1115/IMECE2020-23888","url":null,"abstract":"\u0000 Many technologies have been developed to improve the ability of fluids to transport particles. However, the evaluation of particle transport efficiency remains challenging, especially in complex flow such as three-phase flow. In the present research, theoretical and experimental work is conducted to develop a new perspective of evaluating particle transport technologies, particle transport coefficient (PTC) as the particle transport distance per unit volume of water consumption considering the transport efficiency and environmental cost. The mathematical form of the PTC for the steady-state transport case is derived, followed by three special transport cases: (a) PTC = 0 when particle settled or stuck, (b) PTC = infinity in the vertical direction, considering gravity or buoyant with carrier fluid stationary, while PTC = 0 in a horizontal pipe due to particle settlement; and (c) PTC = 2 for an infinitely small particle at the center of a fully-developed laminar flow in a pipe. Furthermore, the fluid property and surface property influence on PTC are experimentally demonstrated. We believe the proposed approach can promote the development of particle transport technologies.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123903411","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":"Fluid Structure Interaction Simulation of a Benchmark Configuration With a Stress Blended-Eddy Simulation Model","authors":"H. P. Pratomo","doi":"10.1115/IMECE2020-23101","DOIUrl":"https://doi.org/10.1115/IMECE2020-23101","url":null,"abstract":"\u0000 In this work, the application of a shear stress transport based-RANS/LES turbulence modelling approach on a fluid-structure interaction (FSI) benchmark is considered after a transient computation of turbulent flow over the configuration on an LES quality mesh is to be performed. Within the unsteady decoupled simulation the scale resolving method successfully produces complex unsteady eddy sizes behind the reference test case. At a subcritical Reynolds number, a numerical Strouhal number of 0.184 which is close to a reference value of 0.18 is demonstrated by the RANS/LES turbulence model. In this scenario, a rubber added on the back part of a fixed circular cylinder is treated as a rigid thin plate during the pure flow simulation. On the LES grid resolution, the shielding function resided in the hybrid limiter of the scale resolving formulation is found to be strong to safeguard the activation of the RANS mode in the near wall region where the demarcation line between the RANS and LES modes uniquely resembles the geometry. Moreover, in the FSI simulation resolved turbulence scales interacting with moving and deforming rubber immersed in the subcritical Reynolds number-turbulent flow are successfully captured by the hybrid modelling technique coupled with a structural solver under the coupling procedure of an implicit partitioned approach. Similar with earlier studies with different scale-resolving proposals on the same FSI case, a periodic oscillating motion of the rubber that is produced from a phase-averaging method is also demonstrated in this present investigation. Nevertheless, a non-physical deformation of the rubber in the spanwise direction occurs. The new FSI result is evaluated with existing results from earlier works as a pivotal basis for further researches, such as implementations of new mesh stiffness model and filter width.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130717400","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":"Numerical Study of the Flow Inside a Modular Bag Filter From a Biomass Power Plant","authors":"M. Vinha, J. Silva, S. Teixeira, André Gomes, J. Teixeira","doi":"10.1115/IMECE2020-23484","DOIUrl":"https://doi.org/10.1115/IMECE2020-23484","url":null,"abstract":"\u0000 Nowadays, one of the most important issues in modern industrial power plants is air pollution. Solid particles are harmful to human health and are one of the main pollutants released through the combustion of biomass.\u0000 The main goal of this paper was to study the flow in a modular bag filter of a dedusting system implemented in a Biomass Power Plant, in order to improve the filtration of the solid particles coming from the biomass combustion. For this purpose, a numerical model using the ANSYS Fluent software was developed.\u0000 Initially, it was necessary to model the dedusting system in the software SolidWorks. Once this system had 10 modules and to facilitate the simulation in Fluent, only one module was modeled with proper simplifications. Once the geometry was modeled, it was exported to Fluent where the mesh was made, with special care in the inlet of the module, as it is the most critical zone for the simulation. It was simulated 4 cases, where the action of each individual filter was considered. The first case study considered the nominal operating conditions of a biomass power plant. Thereafter, two cases with different mass flow rates were simulated to assess if there were any differences in the flow inside the bag filter. Lastly, it was studied the influence of the vertical baffle size that is in the inlet of the module.\u0000 Comparing the four simulations, it was concluded that in the first three cases, the flow is very similar, with only a slight increase in the velocity in the study with higher flow, as expected. Furthermore, it was concluded that using a smaller vertical baffle, the flow would be improved, once the filters close to the inlet would be more used.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"310 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132372418","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":"Vibration Analysis in Multiple Close Proximity Flow Restrictions","authors":"R. Verma, George Horiates, Nicholas Kanellis","doi":"10.1115/IMECE2020-23804","DOIUrl":"https://doi.org/10.1115/IMECE2020-23804","url":null,"abstract":"\u0000 In this study, a segment of water conveyance system at a chemical manufacturing facility is under investigation. The pipe segment under investigation conveys a daily average flow of five million gallons of water per day (MGD) from the river to a water treatment plant. The exact age of the pipe system is unknown as limited construction or maintenance information exists. The study area is a pipe segment near the treatment plant where three flow restrictions exist within a 30-foot distance bounded by a T-junction and a water filtration plant. These restrictions include two self-actuated butterfly valves and an orifice plate on a 16-inch diameter steel pipe, buried approximately three feet below ground surface. When standing in the study area, heavy vibrations are felt at the ground surface. The valves and orifice plate are to control flowrate and reduce pressure from 80 PSI to 45PSI as the flow enters the water treatment plant.\u0000 Flow restrictions in close proximity can cause cavitation, water hammer and other flow phenomena within a pipe system. This can result in excessive wear of the pipe’s inner walls and valves which may compromise the structural integrity and/or function of the system. Computational fluid dynamics (CFD) software is a useful tool for determining if the conditions for the various flow phenomena are present in a system.\u0000 The flow characteristics were numerically calculated in MATLAB then computationally modeled in AFT Fathom. The purpose of the numerical analysis was to describe the stability of the fluid flow at discrete points in the pipe network and identify the network segments with significantly unstable flow profiles. The purpose of the AFT Fathom CFD model purpose was to provide a continuous simulation of the flow stability in the pipe segment and provide a more robust description of the flow profiles in the network. While Fathom cannot explicitly predict cavitation or water hammer, the kinematic parameters produced by the Fathom model and the physical conditions observed in the study indicate that water hammer is likely occurring.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134027335","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":"Research on Flow and Heat Transfer Characteristics of Multiple Impinging Jets on a Moving Conveyor Belt","authors":"R. Liu, Yu Sun, J. Ni","doi":"10.1115/IMECE2020-23272","DOIUrl":"https://doi.org/10.1115/IMECE2020-23272","url":null,"abstract":"\u0000 Turbulent impinging jets at three different jet nozzle forms were numerically analyzed using the SIMPLE algorithm and k-epsilon turbulent model to investigate the flow field and heat transfer characteristics. The food placed upon a moving conveyor belt cooled by series of impinging jets under a specific condition. Three semi-confined domains with different jet nozzles were established, thereby with slot, rectangular, and funnel-shaped nozzles, respectively. Based on computational fluid dynamic (CFD) calculations, distributions of the temperature and wind velocity at four critical cross-sections of domains were compared. The results reveal that the freezing rate of foods mainly relates to temperature and wind velocity. For three semi-confined domains, the impinging jet with slot nozzles produces higher exit wind velocity, lower center temperature, and a better mass flow uniformity than others, which could better improve the heat transfer performance, and could increase the freezing rate of foods.","PeriodicalId":112698,"journal":{"name":"Volume 10: Fluids Engineering","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132966549","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}