Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics最新文献

{"title":"Uncertainty Estimation in CFD Simulations of Erosion for Elbows","authors":"E. shojaie, T. Sedrez, F. Darihaki, S. Shirazi","doi":"10.1115/fedsm2021-65987","DOIUrl":"https://doi.org/10.1115/fedsm2021-65987","url":null,"abstract":"\u0000 Computational Fluid Dynamics (CFD) is used extensively in the industry and academia for analyzing the motion of solid particles and the associated solid particle erosion that may occur in various pipe components. However, CFD simulations always carry levels of inherent uncertainties due to the numerical approximations of governing equations, generated grid, and turbulence models. Also, because of the complex nature of solid particle erosion, additional uncertainties are added to erosion prediction simulations. Aspects such as particle size, number of impacts, particles’ initial condition, near-wall mesh effects, forces considered in particle tracking procedures, particle-particle interaction, and near-wall particle-fluid interactions are all possible sources of uncertainties associated with erosion prediction in CFD. Furthermore, unique problems that accompany discrete phase handling and erosion calculation needed for the industrial applications magnify the importance of uncertainty estimation in erosion calculations. Commercially available CFD codes are used with user-developed subroutines to investigate particle erosion prediction uncertainties, numerically in elbows, by considering gas and liquid flow for several pipe sizes. Moreover, different particle sizes, inlet flow velocities, turbulence models, wall functions, and erosion models are examined. According to the ASME’s Verification and Validation (V&V) standard, uncertainties are divided into 3 categories; input, numeric, and modeling. Thus, it is possible to utilize the ASME’s standard as guidance to predict uncertainty for erosion simulations. Furthermore, an extra parameter was considered for uncertainties to account for the uncertainties induced by different simulation procedures and erosion models. The current investigations resulted in developing a framework for estimating uncertainties of erosion simulation. For each simulation result, two bounds (upper and lower) were predicted for erosion. The results show that the Reynolds Stress turbulence model (RSM) and Arabnejad’s erosion model usually predict results corresponding to the lowest uncertainties.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126131128","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":"Application of Scale-Resolving Simulations and Hybrid Models for Contraction-Expansion Pipe Flows","authors":"F. Darihaki, Jun Zhang, S. Shirazi","doi":"10.1115/fedsm2021-65917","DOIUrl":"https://doi.org/10.1115/fedsm2021-65917","url":null,"abstract":"\u0000 Contractions and expansions are commonly found in various piping systems including flow control in the oil and gas industry. They impose complex flow characteristics such as flow recirculation, boundary layer separation and unsteady re-attachment. Computational Fluid Dynamics (CFD) using RANS simulations can offer general information about the time-averaged flow properties in expansion and contraction geometries including the pressure drop across the fitting. However, they generally fail to provide details of turbulent flow such as shedding of vortices and high turbulent intensities which are observed in experimental data at the expansion and contraction regions. Large Eddy Simulations (LES) can resolve a turbulence spectrum by filtering Navir-Stokes equations over the computational cells. In this study, LES is utilized to examine a sudden-contraction and expansion pipe flow. Furthermore, Stress-Blended Eddy Simulations (SBES) as a hybrid LES-RANS model is employed for comparison. All of these Scale-Resolving Simulations (SRS) are examined against the experimental data and compared to commonly used RANS simulations. Various flow parameters are examined at different locations for a 50.8 mm pipe which is suddenly reduced to a 25.4 mm pipe and then suddenly expands to the original size, and highlights of each model are presented. The details of the turbulent flow in these geometries are critical to many applications such as particle-laden flows and this investigation would provide insight into the appropriate flow modeling in the expansion and contraction geometries.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123294286","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":"Three-Dimensional Weighted Multiple-Relaxation-Time Pseudopotential Lattice Boltzmann Method for Multiphase Flow","authors":"Jun Tang, Sheng-Fei Zhang, Huiying Wu","doi":"10.1115/fedsm2021-65506","DOIUrl":"https://doi.org/10.1115/fedsm2021-65506","url":null,"abstract":"\u0000 The pseudopotential lattice Boltzmann (LB) method has been widely used for simulating multiphase flow due to its concise concept and computational simplicity. In this paper, based on the weighted orthogonal transformation matrix, a three-dimensional (3D) weighted multiple-relaxation-time pseudopotential lattice Boltzmann method (WRMT-LBM) is developed, in which the standard lattice stencil D3Q19 is adopted. Compared with the classical multiple-relaxation-time pseudopotential lattice Boltzmann method (CMRT-LBM) based on the orthogonal transformation matrix, the expressions of the equilibrium density distribution function and discrete force term in moment space are simplified in the present model, which contributes to simplifying the program implementation and improving the computational efficiency. Moreover, an additional discrete source term in moment space compatible with the proposed model is introduced to achieve tunable surface tension. A series of numerical tests are then implemented to investigate the performance of the proposed model. Compared with the CMRT-LBM, the results of the present model can achieve lower spurious velocity and higher computational efficiency while keeping comparable accuracy. Furthermore, using the present model, three benchmark cases, including droplet oscillation, droplet impacting on wall and droplet impact on thin film, are performed to investigate the performance of this model. The numerical results are in good agreement with the analytical solutions or the empirical correlations in the literature, which demonstrates that the present model can simulate the multiphase flow with large density ratio.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129954751","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":"Viability of OpenFOAM as the Numerical Engine for Augmented Reality Sandbox","authors":"Elizabeth Smith","doi":"10.1115/fedsm2021-65991","DOIUrl":"https://doi.org/10.1115/fedsm2021-65991","url":null,"abstract":"\u0000 Many augmented reality sandboxes use a single purpose implementation of standard numerical schemes to solve the Saint-Venant equations for shallow water in real time. This work evaluates the open-source computational fluid dynamics (CFD) package OpenFOAM as an alternative to the custom implementations traditionally used. Many sandboxes are used in educational and research settings and CFD engines with costly licensing was not desirable. The goal of this work is to identify or create an OpenFOAM solver that handles features such as dry conditions and complex topographies. The existing shallowWaterFoam solver was identified as the best candidate but required modification to handle scenarios representative of the target application. Replacing the existing custom numerical algorithm with the OpenFOAM software will more easily allow future incorporation additional phenomena.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123488339","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":"Minimum Wall Distance Computations With Time-Dependent Geometry for CFD","authors":"Liwu Wang, Jianli Feng, Yu Liu, Sijun Zhang","doi":"10.1115/fedsm2021-61454","DOIUrl":"https://doi.org/10.1115/fedsm2021-61454","url":null,"abstract":"\u0000 This paper presents an efficient and scalable method to calculate the minimum wall distance (MWD), which is necessary for the Reynolds-Averaged Navier-Stokes (RANS) turbulence models. The MWD is described by the distance field function which is essentially a partial differential equation (PDE). The PDE is a type of convection-diffusion equation and can be solved by existing computational fluid dynamics (CFD) codes with minor modifications. Parallel computations for the PDE are conducted to study its efficiency and scalability. Encouraging results are obtained and demonstrate the present method is more efficient than all the alternate methods.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126373897","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":"3-D Computational Study of a Diffuser Augmented Micro Wind Turbine","authors":"M. Kiran, Aakash Rajawat, Pritanshu Ranjan","doi":"10.1115/fedsm2021-65661","DOIUrl":"https://doi.org/10.1115/fedsm2021-65661","url":null,"abstract":"\u0000 The present study focuses on the design optimization of a 3D DAMWT (Diffuser Augmented Micro Wind Turbine geometry). DAMWTS are compact devices with a swept area of only few square meters and energy production capacity of a few kilowatts. Their small size makes it convenient for domestic power generation. The box-shaped shroud makes it possible to stack multiple DAMWTS in an array configuration, thereby multiplying power output. 3-D CFD simulations were carried out using the k-ω SST turbulence model to compare the performance characteristics of different turbine geometries with a square inlet. With a constant shroud diffuser angle of 12 degrees as obtained in a previous study, the shroud nozzle angle and curvature were varied to obtain the maximum velocity factor and minimize flow stagnation at the inlet. Best performance was obtained with a nozzle angle of approximately 27 degrees and semi-concave curvature, with a velocity factor of 1.2. Further increase in nozzle angle resulted in a decline in performance and an increased flow stagnation. To analyze the influence of stacking on flow characteristics, a computational study of two DAMWTS placed horizontally next to each other was carried out. An investigation of the effectiveness of Vortex Generators in inhibiting flow stagnation at the inlet was also conducted.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117084232","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":"An Investigation of the Effects of Volume Fraction on Drag Coefficient of Non-Spherical Particles Using PR-DNS","authors":"Pratik Mahyawansi, Cheng-Xian Lin","doi":"10.1115/fedsm2021-65809","DOIUrl":"https://doi.org/10.1115/fedsm2021-65809","url":null,"abstract":"\u0000 Prediction of the drag coefficient is required in gas-particle multiphase flow modeling and simulation. Experimental data and correlations on the fixed-bed system of spherical particles with high volume fractions for various possible arrangements are available in the literature. However, the effect of volume fraction on the drag coefficient of non-spherical particles is not well studied. In solving the momentum equation, the volume fraction plays a vital role in determining the flow resistances. In this paper, we study the impact of volume fraction in the range of 0.069 to 0.65 on the drag coefficient using the computational fluid dynamics (CFD) simulation of air for Reynold number in the range of 10 to 10000 using particle resolved direct numerical solution (PR-DNS). Regular non-spherical particles such as a cube, tetrahedron, and spheroids are used in this study since their single particle’s drag coefficient data are available in the literature for comparison. For this work, the simulations are carried out in the Ansys Fluent using polyhedral mesh, which consumes significantly less computational time and power. The study showed the sphericity and volume fraction have significant impact on the bed pressure drop and average drag coefficient of the particles in the bed especially in high Reynolds number regime. The bed of the spheroid experiences the lowest drag being the most streamlined particle, and the particles with the edges result in a large drag coefficient due to flow separation at the discontinuity. The vector plots verify this behavior where large wake regions are observed behind the tetrahedron particle.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129116903","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":"Turbulent Flow Simulation of Supercritical Hydrothermal Synthesis in T-Shaped Channel","authors":"Takashi Furusawa, Kenta Matsui, Shuto Yatsuyanagi, S. Yamamoto, A. Yoko, T. Adschiri","doi":"10.1115/fedsm2021-66023","DOIUrl":"https://doi.org/10.1115/fedsm2021-66023","url":null,"abstract":"\u0000 Turbulent mixing flows of supercritical water and a metal-salt solution were investigated using Reynolds-averaged Navier–Stokes (RANS) simulations. The mass conservation equations for metal-salt and metal-oxide in an aqueous solution, which were coupled with Navier–Stokes equations and the Shear Stress Transport (SST) turbulence model, were solved by considering production by the hydrothermal reaction. The reaction rate in the numerical simulation was interpolated linearly using the experimental data. The mixing flows in a T-shaped channel for various Reynolds numbers were simulated numerically. Fluid mixing causes a hydrothermal reaction in a high temperature region. In a situation with a low temperature and low Reynolds number, the mixing became a steady state, and the metal oxide was generated along the channel wall. For a high Reynolds number, the periodic vortexes were observed at the mixing point and the fluid temperature increased rapidly. A numerical simulation reproduced the apparent reaction rate of the experimental measurements, except for the low Reynolds number case. The time-averaged temperature distributions indicated that the increasing temperature rate in the mixing reactor depends on the inlet supercritical water temperature, which affects the distribution of the concentration of metal oxide. If the turbulence effects were ignored in low-temperature instances, the apparent reaction rate was estimated to be quite low. The turbulent diffusivity and thermal conductivity crucially affected the conversion rate, especially for conditions with a low Reynolds number.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131952032","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":"Transient Rayleigh-Bénard Thermal Convection With Radiation Heat Transfer in Participating Media Using the Control Volume Finite Element Method (CVFEM) and Lattice Boltzmann Method","authors":"R. Chaabane, A. Jemni, F. Aloui","doi":"10.1115/fedsm2021-65629","DOIUrl":"https://doi.org/10.1115/fedsm2021-65629","url":null,"abstract":"\u0000 In this paper, a gas-kinetic Bhatnagar-Gross-Krook (BGK) model is constructed for the Rayleigh-Benard thermal convection transfer in a two-dimensional cavity containing an absorbing, emitting, and scattering medium, where the flow field and temperature field are described by two coupled Lattice Boltzmann Method (LBM) BGK models. Heat radiation is solved using the Control Volume Finite Element Method (CVFEM). The two-dimensional Rayleigh-Benard thermal convection with radiation is studied and numerical results are compared with some available benchmark solutions and a good agreement has been observed.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128766011","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":"Volume of Fluid Simulations of Copper Droplet Splat and Sensitivity to Modeling Methods","authors":"L. Florio","doi":"10.1115/fedsm2021-65318","DOIUrl":"https://doi.org/10.1115/fedsm2021-65318","url":null,"abstract":"\u0000 Liquid droplet interactions with solid surfaces are fundamental to a wide range of phenomena from novel manufacturing processes, ice accretion on surfaces, to ablation and fouling build-up when droplets are carried with fluid flow along a flow path. Computational fluid-dynamics based simulations offer a controlled environment in which to explore the details of the droplet motion, deformation, or break-up and solidification and melting as droplet impingement on a surface occurs. The operating, material, or geometric conditions can be altered and the resulting changes in the droplet related phenomena can be used to gain the information needed to control the droplet related processes for an intended purpose. The present work investigates the sensitivity of the predicted splat development as a single copper droplet impact upon a cool copper substrate to variations in a volume of fluid based computational modeling method.\u0000 One liquid copper droplet is assigned an initial velocity and temperature and is set to impact a cold solid copper surface. The splat profile, as time progresses, is compared to the results in the literature. Among the computational modeling method changes investigated are the surface tension treatment, the solution method for the volume fraction equation, the volume fraction time sub-step calculation method, the volume fraction cut-off value and Courant number, the frequency of the volume fraction updates, the volume fraction discretization method, the mushy zone parameter, and mesh refinement. The study results can be used to provide information to aid in the generation of the models that can more accurately interrogate droplet-surface interactions.","PeriodicalId":359619,"journal":{"name":"Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121644413","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}