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Applied Computational Fluid Dynamics
Бразилия
Добавлен 28 окт 2019
CFD has become a very common tool in the design of many products for academic/industrial applications. Currently, there are many commercial and open source codes available, developed for use by both engineers and researchers.
At the moment, CFD users need to have reasonable knowledge in this area. The current channel is an attempt to fill that need.
If you have any suggestion for new video topics or have spotted any error, you are welcome to post them in the comments section or send an email to mojtaba@lts.coppe.ufrj.br
At the moment, CFD users need to have reasonable knowledge in this area. The current channel is an attempt to fill that need.
If you have any suggestion for new video topics or have spotted any error, you are welcome to post them in the comments section or send an email to mojtaba@lts.coppe.ufrj.br
Aerodynamic Evaluation of Wind Turbines: BEM vs. FVW vs. CFD
This video presents the three commonly used methods for the evaluation of wind turbine aerodynamics including
00:02:19 Blade element momentum (BEM)
00:43:38 Free vortex wake (FVW)
00:50:57 Computational fluid dynamics (CFD)
Traditionally, it is common to use the BEM theory to assess the aerodynamic behavior of a wind turbine. However, over the recent years, the size of wind turbines, especially the offshore ones, has undergone a dramatic increase due to substantial economic benefits. The large blades of these huge machines are subject to large deformations due to increased flexibility and non-straight pre-bended blades. This, as a result, complicates highly the aerodynamics of wind turbine...
00:02:19 Blade element momentum (BEM)
00:43:38 Free vortex wake (FVW)
00:50:57 Computational fluid dynamics (CFD)
Traditionally, it is common to use the BEM theory to assess the aerodynamic behavior of a wind turbine. However, over the recent years, the size of wind turbines, especially the offshore ones, has undergone a dramatic increase due to substantial economic benefits. The large blades of these huge machines are subject to large deformations due to increased flexibility and non-straight pre-bended blades. This, as a result, complicates highly the aerodynamics of wind turbine...
Просмотров: 2 227
Видео
CFD simulation of the IEA 15 MW wind turbine at rated wind speed
Просмотров 2,3 тыс.Год назад
The simulation is performed using URANS with elliptic-blending Reynolds stress turbulence model available within the STAR-CCM code.
Governing Equations of Fluid Dynamics: Lattice Boltzmann Method to Navier-Stokes Equations
Просмотров 8 тыс.Год назад
The present video provides a thorough introduction about Governing Equations of Fluid Dynamics in Mesoscopic and Macroscopic Scales from Lattice Boltzmann Method to Navier-Stokes Equations. Video Outline: 0:00:00 - Introduction 0:01:08 - Microscopic Scale 0:01:55 - Mesoscopic Scale 0:02:42 - Macroscopic Scale 0:03:40 - Lattice Boltzmann Method 0:11:53 - Macroscopic Scale 0:12:10 - Eulerian and ...
Tutorial: CFD simulation of the SUBOFF underwater vehicle moving near the free surface (STAR-CCM+)
Просмотров 9 тыс.2 года назад
In this simulation, a 1/1-scale of the bare hull axisymmetric SUBOFF geometry is used. The model has a length to diameter ratio equal to L/D = 8.575. The simulation set-up is performed for submergence depth of 1.1D (D is the SUB-OFF maximum diameter). Also, the length-based Froude number is assumed to be 0.462. Link to the geometry: github.com/MojtabaMaali/SUBOFF-Geometry/raw/main/mainbody.SLDP...
Tutorial: Generation of a high-quality mesh for CFD simulations of wind turbines (STAR-CCM+)
Просмотров 11 тыс.2 года назад
This video presents a step-by-step tutorial to set up a CFD simulation of a wind turbine using STAR-CCM . Here, we are gonna learn how to set up a URANS-based CFD model for the evaluation of aerodynamic behavior of wind turbines. In particular, a systematic methodology is presented for the generation of a CFD grid with a proper resolution, which provides a reasonable compromise between computat...
Finite Volume Method in CFD: A Thorough Introduction
Просмотров 16 тыс.2 года назад
This video presents a thorough introduction about the finite volume method. In this video, first, the governing equations of fluid flows, including the conservative and non-conservative forms, are discussed. After that, the finite volume method is presented in detail. Video Outline: 0:00:00 - Finite Volume Method: A Thorough Introduction 0:00:21 - Governing equations of fluid flows 0:03:07 - Co...
Pressure-Based and Density-Based Solvers in CFD
Просмотров 11 тыс.2 года назад
This video presents the pressure-based and density-based solvers in CFD. Both the pressure-based and density-based solvers are used to solve the mass and momentum conservation equations, which describe the fluid flows. The density-based solvers are mainly used for compressible flows, which are encountered at high speeds. These solvers are also referred to as the coupled solvers. However, the pr...
Tutorial: Generation of a High-Quality Cartesian Mesh Using the Trimmed Cell Mesher (STAR-CCM+)
Просмотров 5 тыс.2 года назад
In this video, you will learn how to generate a high-quality Cartesian mesh, using the trimmed cell mesher within the STAR-CCM . The trimmed cell mesher has the ability to produce a high-quality Cartesian mesh with a minimal cell skewness angle. However, in order to generate a high-quality Cartesian mesh using the trimmed cell mesher, it is necessary to have some knowledge about some basic feat...
How to Write a CFD Report/Paper?
Просмотров 4,9 тыс.2 года назад
In this video, you will learn how to write a CFD report or paper. In order to write a report or paper based on CFD solutions, the following aspects regarding the CFD model and the solutions must be described adequately: 00:46 General Numerical Method 02:24 Grid System 04:04 Numerical Schemes 05:20 Boundary Conditions 07:09 Turbulence Modeling 09:02 Free-surface Treatment 09:28 Computations 10:4...
Tutorial: Setting up an External Aerodynamics Simulation (STAR-CCM+)
Просмотров 14 тыс.2 года назад
This video presents a tutorial on how to set up an external aerodynamics simulation in STAR-CCM . Here, a virtual wind tunnel is created around a simple geometry, which is a 6:1 prolate-spheroid, to analyze the aerodynamic behavior of this body. The prolate-spheroid has an angle of incidence equal to 20 degrees with respect to an inflow with a constant speed of 47.957 m/s. You can access the ge...
Tutorial: Checking the Validity and Quality of Mesh (STAR-CCM+)
Просмотров 16 тыс.2 года назад
This video presents a tutorial about checking the overall validity and quality of a volume mesh using STAR-CCM . Here, you learn how to check the validity and quality of mesh using the following parameters in STAR-CCM : 1. Cell skewness angle, 2. Face validity metric, 3. Cell quality metric, 4. Volume change metric, 5. Chevron quality indicator, You further learn how to locate the cells with ba...
RANS vs. URANS
Просмотров 7 тыс.3 года назад
This video explains the difference between RANS and URANS. Video Outline: 0:00 - Difference between RANS and URANS 0:06 - RANS and URANS equations 1:37 - Ensemble Average vs. Time Average 2:28 - RANS vs. URANS
Mesh Generation in CFD: Prism (Inflation) Layer Mesh
Просмотров 10 тыс.3 года назад
This video presents a practical methodology for the generation of a reliable prism layer mesh for your CFD simulations. Video Outline: 0:00 - Mesh Generation in CFD: Prism Layer Mesh 1:22 - Prism layer mesh generation 2:21 - Thickness of the prism layer 3:32 - Number of layers 9:09 - Assessment of the accuracy of the proposed methodology for the prism layer mesh generation The equations used in...
RANS Turbulence Models: Which Should I Choose?
Просмотров 14 тыс.3 года назад
In this video, a quick overview of the most important RANS turbulence models are presented. As you may know, a large variety of turbulence models has been developed with an attempt to close the RANS equations. This makes the choice of a suitable turbulence model for a specific simulation a bit of a challenge. Therefore, this video can be considered as a guideline for the selection of the most s...
RANS Turbulence Modeling: Prediction of Near-Wall Turbulence
Просмотров 3,2 тыс.3 года назад
RANS Turbulence Modeling: Prediction of Near-Wall Turbulence
Fluid-Structure Interaction (FSI) Simulation of a Wind Turbine
Просмотров 3,9 тыс.3 года назад
Fluid-Structure Interaction (FSI) Simulation of a Wind Turbine
Tutorial: CFD simulation of a Buoy Motions in Waves Using DFBI and Overset Mesh (STAR-CCM+)
Просмотров 21 тыс.3 года назад
Tutorial: CFD simulation of a Buoy Motions in Waves Using DFBI and Overset Mesh (STAR-CCM )
SIMPLE Algorithm in Staggered and Collocated Grid Arrangements
Просмотров 8 тыс.3 года назад
SIMPLE Algorithm in Staggered and Collocated Grid Arrangements
Vertical Motions of a Buoy in Head Waves
Просмотров 1,4 тыс.3 года назад
Vertical Motions of a Buoy in Head Waves
Tutorial: CFD simulation of a Wind Turbine (STAR-CCM+)
Просмотров 23 тыс.3 года назад
Tutorial: CFD simulation of a Wind Turbine (STAR-CCM )
Verification vs. Validation: Precision vs. Accuracy
Просмотров 9953 года назад
Verification vs. Validation: Precision vs. Accuracy
Free Surface Modeling: Volume of Fluid (VOF) Approach
Просмотров 8 тыс.3 года назад
Free Surface Modeling: Volume of Fluid (VOF) Approach
Upwind schemes under strong convection
Просмотров 1,1 тыс.3 года назад
Upwind schemes under strong convection
RANS Equations: Ensemble Average vs. Time Average
Просмотров 9 тыс.4 года назад
RANS Equations: Ensemble Average vs. Time Average
Turbulent wake behind a wind turbine
Просмотров 4,5 тыс.4 года назад
Turbulent wake behind a wind turbine
Pressure-Velocity Coupling - Staggered and Collocated Grid Arrangements
Просмотров 5 тыс.4 года назад
Pressure-Velocity Coupling - Staggered and Collocated Grid Arrangements
Discretization of the Convective Term - Upwind Schemes
Просмотров 6 тыс.4 года назад
Discretization of the Convective Term - Upwind Schemes
Discretization of the Diffusive Term - Over-Relaxed Approach
Просмотров 1,2 тыс.4 года назад
Discretization of the Diffusive Term - Over-Relaxed Approach
Transient Simulations - Discretization of the Temporal Term
Просмотров 5744 года назад
Transient Simulations - Discretization of the Temporal Term
Your equations and their description is not correct. You mix up incompressible and compressible parts. The compressible equations are not mass, momentum and equation of state but mass, momentum, enthalphy / energy and equation of state.
Superb presentation I've ever seen!
Your tutorial is very useful! Thank you very much! Have you compared the calculated results with the experimental datas? Can you provide the literature related to this experiment?
Thank you very much for your interest in my contents. Please have a look at this paper? doi.org/10.1007/s40430-022-04012-w
@@CFD_Mojtaba thanks a lot
Hi, guys! This is a great video. However, I wasn't able to calculate the FTL and boundary layer thickness the same you did. Could you please provide the value of the dynamic viscosity (v)? Thank you!
very informative video sir how can I contact you? sir can I get your email I have a problem with my simulation
Hello. thanks for your informative video. could you please share the presentation ?
Thank you very much for your interest. Please send an email to this address: mojtaba@lts.coppe.ufrj.br
I am doing CFD research regarding the wind turbine. And thanks for your explanation. Well done!
Hello. Excuse me, could you help me? I'm modeling a tidal turbine, I need to find the average thrust and average power. But I didn't understand how you set up the power report. You multiplied the RPM by some figure, and then multiplied it by the torque report. What were those second digits? Is this transformation rpm into rps?
Total pressure=Static+Dynamic. In CFD by Ansys does not match. Why?
could you send me the .sim file without mesh ?
is it possible to share the simulation file with all settings done, but without mesh
Which software it is???
Thank you for your nice work. Can you tell me how to make Q-Criterion in a region (not whole calculation domain)? Thanks!
Strange that the buoy not tilting against waves. (pitch) So this is not reality, how to trust?
Very Good and Clear Presentation! I wish every teacher could explain this well, I had a Calculus Professor who did this well which combined with a Small class size was perfect for me. Thanks for the time and effort that you put into this work. You could do a Book and a Set of DVDs. Or an online Interactive book/series!
Can you do a Presentation like this on Landau Damping?
Thank you very much for this comment; unfortunately, I have been extremely busy lately working on several projects. Maybe later.
Great Presentation, Very Well Done - This is really a University Level Class At Home, Thank You! This done better and More Clearly than at most Universities I Bet!
can someone suggest how to do a free decay test for heave in this simulation
Hello Dear, Thank you for your comment. You just need to apply some initial displacement in the heave direction without considering any waves. In this video you can learn hoe to simulate the calm water case: ruclips.net/video/BZQ8vOz8BtU/видео.html
@@CFD_Mojtaba Thank u sir
ive tried this 4 times. but it always have reversed flow. but it just between +- 500 surfaces. I think we need to do more refinement isn it.
Using Regions > VirtualWindtunnel > Boundaries and then edditing the boundaries doesnt give me the ability to adjust meshing paramters, i only get "Physics conditions and values". Do you have any ide what my mistace could be? I have obviously created a Mesh continoum already
Thank you for your comment! Note that the Region-based meshing is not available in the new versions of STAR-CCM+. You need to generate mesh using Part-based meshing. Please have a look at this video: ruclips.net/video/kaCoBw8ynhM/видео.html
Dear Mujteba could you please upload the 1080p version of this tutorial? Regards from ITU
Thank you very much for your comment; unfortunately, this is the only version that I have.
Dorood Mr. Amiri, This was a great tutorial. I was wondering though about a simple confusion of mine that CFL is measured based on velocity, temporal discritization and spatail discetrization, and usually 0.25 is selected for it. WHY did you select 95?
Dear Shayan, thank you very much for your comment. Note that the condition of having a CFL less than 0.25 is generally more important, when the problem is transient in nature and we are interested in time-varying variables.
Hello! Could you please illustrate the value you used in the time step and you says"However, note that the estimation of the time - step size should also be in such a manner that in each time - step, the overset mesh moves a distance smaller than the size of the smallest cell in the background mesh. Therefore, considering this point, the time step size that we are going to use here is 0.001 sec. " from where we can see 0.001 sec in the simulation? please.
Hello, To calculate the time-step size, you can use the Courant number defined according to the minimum cell size within the background mesh, along with the maximum vertical displacement speed of the overset mesh. I hope this helps. Respectfully, Mojtab Maali Amiri.
@@CFD_Mojtaba Hello! I still have a problem in the wave generation shape, I tried more than one example but still not normal shape, could you please let me know after calculating the courant number how we can use it in the simulation? I looked at papers says ::"with a second-order temporal discretization scheme. This results in a Courant number (C=Cg. Δt/ Δx, where Cg is the wave group velocity) less than 0.5; hence, the High-Resolution Interface Capturing (HRIC) scheme that is suited for tracking sharp interfaces is guaranteed to be used during the simulations. My question is after calculating the courant number (C=Cg. Δt/ Δx, how to use the result value in the simulation? Do you have an example, please?
Is this 2D, so the subscripts i and j representing velocity in x and y directions?
Fascinating, glad you're born
This was a very useful video for people who are just getting started and need to learn how to use the programm. What I would have liked to see where more informations ony why we use the values that are shown and what they mean
my star ccm have missing node under tools>update event how can i fix it?
can you help me in my problem?
my vertual tank rotates when i started to run it
Thank you for this interesting tutorial. Can you give me how calculate the wetted length and wetted area.
Why did you not specify the velocity of current and wind in the VOF? Is the Buoy stationary? I have a boat moving at certain speed, where should I specify its velocity?
Good job, I would like to ask how to solve the following problems when I simulation:Error while executing calls to SIMULIA CSS, Abagus error in SMAcseNotifyStart. Director terminated the analysis due to early termination by a client. Please check for errors foreach of the analysis involved in co-simulation and also verify that the co-simulation duration timespecified in the configuration file is correct
wow thank you so much. You helped me a lot
Thank u for such a detailed tutorial…
Can you please help me with my matlab code for SMAC. Can you share your contact email
Please respond
Thank you for sharing! quick question pls, Can we employ symmetry plane boundary conditions at the XZ plane and YZ plane of the buoy? I am guessing it will reduce some computational demand, BTW I am using ANSYS fluent
appreciate your kind share ! could you make tutorial of floating wind turbine with mooring line in Star-ccm+ please ?
Hi your simulations are very impressive. I need a suggestion on my simulations. I should make a DFBI simulation (with Star CCM+) in which the body turn around it self (arround y axis, obviously arround its center of mass) with a time dependent angual velocity. The problema is that with a DFBI simulation I can impose just the initial velocity of the body. Do you have an idea about how I can impose a time dependent angular velocity of the body?
Thank you for your interest in this video, You may need to impose this rotational motion using the rigid body option.
@@CFD_Mojtaba Can we chat (in some way) about this problem? Because it is not so easy.
Can you make a video on ship hull on the mean surface.
Such a great summary !
Thank you for this tutorial, sir can you make the tutorial on air supported floating platform to find its heave response
Thank you for your suggestion. I will try to do this. Note that you probably need to consider that the fluid flow is compressible.
Sir, actually i model the background like you model it for buoy motion tutorials and for air-supported it is a box structure open at bottom but in starm ccm, I was unable to model the opening at the bottom, so I thought of assigning some boundary conditions to the bottom and sir i have a question how can i model air inside the box and tell me how i should model so that backgorund water should go inside it to compress air.what boudary condition i should assign for open part initially it is wall.@@CFD_Mojtaba
@@VikashKumaroe22m021maybe you dont need to model explicitly the air behvior. You can express this effect as an external force.
@@CFD_Mojtaba ok thank you sir and which boundary condition i should assign for bottom surface of box so that background water can go inside it,
Thanks for the lecture. Kindly add references of the information.
Thank you for your comment. The references are added to the video description.
Thank you for the effort. Can these models be coupled with LBM CFD method?
Thank you for this comment, I believe that they can be coupled.
Hi, I am finding the added mass and damping coefficient of different floating structures using the forced heave method. For that I simulated a cylinder in free surface by STARCCM+. I should get a force between -5 and 5N when STARCCM+ gives me a force of 30N. I deduced buoyancy force and hydrostatic force from it still not in the desirable limit. following are the details and solvers i used for the simulation 1) implicit unsteady, VOF for free surface , K - epsilon turbulence with no DFBI and dynamic mesh . I also tried dynamic mesh (overset) and DFBI . 2) I have given velocity in the form of A SIN (wt) form under the motion tool as translation motion. 3) My CFL number is kept below 3 4) Flat wave with zero velocity for air and water. Initial conditions for velocity and pressure are given as zero. 5) slip wall for domain walls , and no slip wall for the translating body. The drive contains my simulation . Can u please take a look at my simulation and tell me wats wrong? drive.google.com/file/d/1rFnL4449stu4aWyPewxF3HGHoxp11_j3/view?usp=sharing
merc mamnoon
@2:03 - What is k on the E(k) graph? The "wer" number?? It was inaudible
Please, have a look at the following video: ruclips.net/video/sUqfatUVUPM/видео.html
@35:09 - How do you obtain the 4th order equation below the vorticity function? It was not clear from the video.
It involves sophisticated mathematical manipulation
Hello, how can i dowload this program ?