Computational Fluid Dynamics in Undergraduate Engineering Education: A Short Introductory Tutorial to OpenFOAM

2016 ◽  
Author(s):  
Ivaylo Nedyalkov ◽  
Martin Wosnik
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Open Source ◽  
Undergraduate Students ◽  
Turbulence Modeling ◽  
Initial Conditions ◽  
Specific Flow ◽  
Undergraduate Engineering ◽  
Wide Range ◽  
The Cost

Computational Fluid Dynamics (CFD) has become a widely used tool in industry as the cost for simulations is usually lower than the cost for multiple experiments. CFD is an effective tool for comparing design alternatives, investigating specific flow features and in some cases it may be the only feasible option for studying engineering flows. As a result, the demand for mechanical engineers with CFD skills keeps increasing. Nevertheless CFD is still not adequately presented in undergraduate engineering curricula, which can lead to expensive mistakes, if for example it is relied on without understanding its limitations. One excellent platform for CFD, which can be introduced to fluid mechanics classes, is the open-source environment OpenFOAM, which is widely used in both academia and industry. In addition to being open-source, OpenFOAM code can be viewed and modified by the user, and a wide range of modules for OpenFOAM are available with new modules being developed constantly. One major disadvantage, however, is that OpenFOAM has a rather steep learning curve and although there are many resources available online, it is difficult to find short introductory courses. A tutorial was developed to provide a brief introduction to OpenFOAM and allow the students to perform simple simulations. Upon completing the tutorial, the students can build their own simulations. The tutorial covers geometry, mesh, boundary and initial conditions, solvers, schemes, post processing, and some additional features, such as shell scripts and parallel processing. A large portion of the tutorial is devoted to the geometry and mesh generation as this is one of the more challenging aspects of OpenFOAM compared to conventional graphical user interface CFD packages. Nevertheless, the students are exposed to the importance of properly setting the other simulation parameters through simple examples — e.g., comparing 2D channel flow simulations using potential flow and using turbulence modeling. One crucial aspect of the tutorial is that students are encouraged to experiment with deliberate modifications of the simulations to experience and understand how some of them do not provide reasonable results. Although the tutorial is rather brief and does not cover the topics in much detail, it aims to familiarize students with the basics of OpenFOAM, so that they can better understand other relevant resources. The OpenFOAM tutorial offers an alternative introduction to CFD compared to commercial CFD packages, which may not be readily available. The tutorial has already been utilized for three consecutive years at the University of New Hampshire, mostly by undergraduate students who worked/are working on senior projects involving CFD. The feedback has been generally positive.

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

scholarly journals Derivation of Global Parametric Performance of Mixed Flow Hydraulic Turbine Using CFD

1970 ◽  
Vol 7 ◽  
pp. 60-64 ◽  
Author(s):  
Ruchi Khare ◽  
Vishnu Prasad Prasad ◽  
Sushil Kumar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Solutions ◽  
Guide Vane ◽  
Hydraulic Turbine ◽  
Francis Turbine ◽  
Mixed Flow ◽  
Flow Equations ◽  
Laboratory Setup ◽  
Wide Range

The testing of physical turbine models is costly, time consuming and subject to limitations of laboratory setup to meet International Electro technical Commission (IEC) standards. Computational fluid dynamics (CFD) has emerged as a powerful tool for funding numerical solutions of wide range of flow equations whose analytical solutions are not feasible. CFD also minimizes the requirement of model testing. The present work deals with simulation of 3D flow in mixed flow (Francis) turbine passage; i.e., stay vane, guide vane, runner and draft tube using ANSYS CFX 10 software for study of flow pattern within turbine space and computation of various losses and efficiency at different operating regimes. The computed values and variation of performance parameters are found to bear close comparison with experimental results.Key words: Hydraulic turbine; Performance; Computational fluid dynamics; Efficiency; LossesDOI: 10.3126/hn.v7i0.4239Hydro Nepal Journal of Water, Energy and EnvironmentVol. 7, July, 2010Page: 60-64Uploaded date: 31 January, 2011

scholarly journals Assessing the Sensitivity of Stall-Regulated Wind Turbine Power to Blade Design Using High-Fidelity Computational Fluid Dynamics

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Andrea G. Sanvito ◽  
Giacomo Persico ◽  
M. Sergio Campobasso
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Field Testing ◽  
Turbine Rotor ◽  
Operating Conditions ◽  
High Fidelity ◽  
Blade Design ◽  
Computationally Efficient ◽  
Wind Speeds ◽  
Wide Range

Abstract This study provides a novel contribution toward the establishment of a new high-fidelity simulation-based design methodology for stall-regulated horizontal axis wind turbines. The aerodynamic design of these machines is complex, due to the difficulty of reliably predicting stall onset and poststall characteristics. Low-fidelity design methods, widely used in industry, are computationally efficient, but are often affected by significant uncertainty. Conversely, Navier–Stokes computational fluid dynamics (CFD) can reduce such uncertainty, resulting in lower development costs by reducing the need of field testing of designs not fit for purpose. Here, the compressible CFD research code COSA is used to assess the performance of two alternative designs of a 13-m stall-regulated rotor over a wide range of operating conditions. Validation of the numerical methodology is based on thorough comparisons of novel simulations and measured data of the National Renewable Energy Laboratory (NREL) phase VI turbine rotor, and one of the two industrial rotor designs. An excellent agreement is found in all cases. All simulations of the two industrial rotors are time-dependent, to capture the unsteadiness associated with stall which occurs at most wind speeds. The two designs are cross-compared, with emphasis on the different stall patterns resulting from particular design choices. The key novelty of this work is the CFD-based assessment of the correlation among turbine power, blade aerodynamics, and blade design variables (airfoil geometry, blade planform, and twist) over most operational wind speeds.

Computational Fluid Dynamics (CFD) Study of the 4th Generation Prototype of a Continuous Flow Ventricular Assist Device (VAD)

2004 ◽  
Vol 126 (2) ◽  
pp. 180-187 ◽  
Author(s):  
Xinwei Song ◽  
Houston G. Wood ◽  
Don Olsen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Blood Flow ◽  
Ventricular Assist Device ◽  
Continuous Flow ◽  
Surrounding Tissue ◽  
Assist Device ◽  
Ventricular Assist ◽  
Wide Range ◽  
Computational Fluid Dynamics Cfd

The continuous flow ventricular assist device (VAD) is a miniature centrifugal pump, fully suspended by magnetic bearings, which is being developed for implantation in humans. The CF4 model is the first actual prototype of the final design product. The overall performances of blood flow in CF4 have been simulated using computational fluid dynamics (CFD) software: CFX, which is commercially available from ANSYS Inc. The flow regions modeled in CF4 include the inlet elbow, the five-blade impeller, the clearance gap below the impeller, and the exit volute. According to different needs from patients, a wide range of flow rates and revolutions per minute (RPM) have been studied. The flow rate-pressure curves are given. The streamlines in the flow field are drawn to detect stagnation points and vortices that could lead to thrombosis. The stress is calculated in the fluid field to estimate potential hemolysis. The stress is elevated to the decreased size of the blood flow paths through the smaller pump, but is still within the safe range. The thermal study on the pump, the blood and the surrounding tissue shows the temperature rise due to magnetoelectric heat sources and thermal dissipation is insignificant. CFD simulation proved valuable to demonstrate and to improve the performance of fluid flow in the design of a small size pump.

CFD Modelling of Multiphase Flows: An Overview

2003 ◽  
Author(s):  
Rajnish K. Calay ◽  
Arne E. Holdo
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Numerical Modeling ◽  
Mathematical Models ◽  
Cfd Modelling ◽  
Two Phase ◽  
Wide Range ◽  
Computational Fluid Dynamics Cfd ◽  
Numerical Modeling Of Flows

The Computational Fluid Dynamics (CFD) is now increasingly being used for modeling industrial flows, i.e. flows which are multiphase and turbulent. Numerical modeling of flows where momentum, heat and mass transfer occurs at the interface presents various difficulties due to the wide range of mechanisms and flow scenarios present. This paper attempts to provide a summary of available mathematical models and techniques for two-phase flows. Some comments are also made on the models available in the commercially available codes.

Open-Source Computational Fluid Dynamics in Engineering Education

2019 ◽  
Author(s):  
Ivaylo Nedyalkov
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Engineering Education ◽  
Open Source ◽  
Code Base ◽  
Undergraduate Engineering Education ◽  
Computational Fluid Dynamics Cfd ◽  
The University ◽  
University Of New Hampshire ◽  
Mathematics And Physics

Abstract Computational Fluid Dynamics (CFD) is widely used in industry but is not discussed sufficiently in undergraduate engineering education. In some cases, CFD is studied only from a mathematical perspective, focusing on computational partial differential equations, and in some cases it is introduced as a black-box tool. A hybrid CFD class was developed for undergraduate and graduate students at the University of New Hampshire, which combines the two approaches. The students are exposed to the mathematics and physics behind CFD, and they also utilize OpenFOAM — an open source CFD package — to work on practical problems. Since the code is open-source, the students are able to see and modify it. Although OpenFOAM is challenging due to the minimum graphical user interface, the code-base environment forces the students to learn what the code is doing. Sample assignments and project submissions from the students are presented in the paper.

Circular Cylinder Exposed to Cross Flow Fluid Forces – Parameters of Influence – Limits of Numerical Models

2003 ◽  
Author(s):  
Christoph Reichel ◽  
Klaus Strohmeier
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Models ◽  
Lift Coefficient ◽  
Cross Flow ◽  
Circular Cylinders ◽  
Rigid Cylinder ◽  
Fluid Forces ◽  
Wide Range ◽  
Dynamics Simulations

In many technical fields, e.g. heat exchangers, circular cylinders are involved in Fluid Structure Interaction (FSI) problems. Therefore correct frequency and magnitude of fluid forces, respectively Strouhal number, drag and lift coefficient are needed. If fluid forces are evaluated with Computational Fluid Dynamics (CFD), mostly flow around a rigid cylinder is used to verify model and numerical methods. Unfortunately experimental as well as numerical results show great variation, making verification and testing of models difficult. Reynolds number is regarded as main influencing parameter for a rigid cylinder in cross flow. Most of experimental deviations can be related to other parameters, which differ from experiment to experiment. In this paper such parameters are specified and it is shown, that a closer look is needed, if one really wants to verify a model. Besides experimental results, which can be found in literature, some parameters are investigated by numerical simulation. Like experiments CFD (Computational Fluid Dynamics) simulations show a huge bandwidth of results, even when the same turbulence model is used. Flow around cylinders separates over a wide range of Reynolds numbers. It will be demonstrated that, using CFD, large deviations in fluid forces can often be related to miscalculation of the point of separation.

Experimental and Numerical Study of Ascending Aorta Hemodynamics Through 3D Particle Tracking Velocimetry and Computational Fluid Dynamics

2013 ◽  
Author(s):  
Utku Gülan ◽  
Diego Gallo ◽  
Raffaele Ponzini ◽  
Beat Lüthi ◽  
Markus Holzner ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particle Tracking ◽  
Particle Tracking Velocimetry ◽  
Numerical Study ◽  
Imaging Techniques ◽  
Ascending Aorta ◽  
Human Aorta ◽  
Wide Range

The complex hemodynamics observed in the human aorta make this district a site of election for an in depth investigation of the relationship between fluid structures, transport and pathophysiology. In recent years, the coupling of imaging techniques and computational fluid dynamics (CFD) has been applied to study aortic hemodynamics, because of the possibility to obtain highly resolved blood flow patterns in more and more realistic and fully personalized flow simulations [1]. However, the combination of imaging techniques and computational methods requires some assumptions that might influence the predicted hemodynamic scenario. Thus, computational modeling requires experimental cross-validation. Recently, 4D phase contrast MRI (PCMRI) has been applied in vivo and in vitro to access the velocity field in aorta [2] and to validate numerical results [3]. However, PCMRI usually requires long acquisition times and suffers from low spatial and temporal resolution and a low signal-to-noise ratio. Anemometric techniques have been also applied for in vitro characterization of the fluid dynamics in aortic phantoms. Among them, 3D Particle Tracking Velocimetry (PTV), an optical technique based on imaging of flow tracers successfully used to obtain Lagrangian velocity fields in a wide range of complex and turbulent flows [4], has been very recently applied to characterize fluid structures in the ascending aorta [5].

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