Ansys Tutorial: Drag and Lift Calculations in ANSYS Fluent

[@steveho4446]

As a beginner of CFD , i have learned alot from this video. Thank you!

[@AdvancedEngineeringTutorials]

Thank you for watching. Glad it is helpful.

[@kevyndex]

Thank you for this video. Saved my final year project because of this

[@spam2908]

Thank you so much. Absolutely clutched my Capstone project !

[@karangajaria8525]

Hey mate, you gotta set the reference values to calculate Cd and Cl. Cd in your result is 500+, which is impractical and unbelievable.

[@z.abidine4443]

1.Can i ask you please about the value of pressure drop ? I mean which two pressure values to refer to ? (18:14) 2.Why does the pressure decrease too much along the y-axis ? (in my case it even goes to negative values) Many thanks in advance.

[@z.abidine4443]

1.Can i ask you please about the value of pressure drop ? I mean which two pressure values to refer to ? (18:14) 2.Why does the pressure decrease too much along the y-axis ? (in my case it even goes to negative values) Many thanks in advance.

[@anujvaishnav8949]

Brother thank you for this I've been able to complete my college project because of this 😀😀

[@AdvancedEngineeringTutorials]

Great 👍

[@aerobyrdable]

Hey, thanks a lot for this one. Helped me immensely

[@AdvancedEngineeringTutorials]

Hi, thank you for watching and thank you for your comments. Glad to hear it!

[@mahsiseua]

why the drag & lift coefficient so high? it is different if we obtain drag & lift force & use equation to obtain their coefficient

[@z.abidine4443]

1.Can i ask you please about the value of pressure drop ? I mean which two pressure values to refer to ? (18:14) 2.Why does the pressure decrease too much along the y-axis ? (in my case it even goes to negative values) Many thanks in advance.

[@AdvancedEngineeringTutorials]

Negative pressure makes sense because of velocity increase on the edges. Like an airfoil. This is an external flow, pressure drop does not make sense to calculate and refer to, but for internal flows, it depends where you want to calculate pressure drop, you can create a plane on each point and calculate the Area average pressure and subtract them for pressure drop.

[@Darwin-bg1pm]

On fluent, why did you not change the reference values? I'm getting different answer if I set it on default or change my values I was trying to confirm the drag coeff of teardrop shape. I used this exact method (except for viscous I used k epsilon - standard wall) and I got a drag coeff of 7 (yes 7 not 0.7 or 0.07). I tried to change the reference values (area and speed), I change the reference value speed from 1m/s to 11.2 m/s (same to my inlet boundary condition speed) and I got a drag coeff of 0.0518 (closer to theoretical drag of teardrop shape, 0.04-0.05). Am I doing this right?

[@Darwin-bg1pm]

Someone in the comment section also pointed out about you, not changing the reference value so I guess that was really a mistake of yours. I hope you put a pinned comment addressing that so future viewers who dont know it will not be getting wrong values. Other than that this video was really helpful especially the inflation part!

[@agnespaculanang3338]

Hello. the lift is lower than the drag in my wind turbine blade simulation, shall i take account the rotating motion of the wind turbine when calculating the lift and drag? amazing video btw

[@music_with_shivansh]

Great tutorial👍 Thank you!

[@AdvancedEngineeringTutorials]

You're welcome!

[@atem_yg]

In the setup, you need to change the reference values acording to your model, right ?? Otherwise it has the default values

[@sirdebster1900]

Awesome video! But I have a question. You got Cd value around 500 for your simulation, but isn't this much higher than a typical coefficient of drag? I am having a similar issue with a simple cylinder in a wind tunnel simulation, in which a typical Cd value should be around 0.5, but I'm getting values around 16. Am I misunderstanding the meaning of what the Cd value measures in ANSYS Fluent? I am pretty new to ANSYS and CFD in general, so this wouldn't be surprising. Thanks.

[@AdvancedEngineeringTutorials]

Thank you for watching and thank you for your comment. Yes, you are correct. If you check the comments it was discussed before. In this video I forgot to define the reference area in the reference values. If you define correct reference area according to fluent documentation (the effective area facing the flow) you will get better results. Hope this is helpful.

[@childhoodforever223]

I am actually having a confusion regarding which reference area and reference length to provide in reference values. In my case, I am trying to calculate drag and lift coefficient for square building by rotating building in Design Modeler at every 15 degree interval from 0 to 90 degrees. So the doubt is that if enter the projected area in the direction of the wind in reference values, it would only be area for drag but what about the other projected area in the direction of lift? And regarding the "length" in reference values, if I'm not mistaken it should be the diagonalish dimension of the building in the wind direction..right !....but if say for example if I am analysing a building whose cross section reduces towards the top...then how to compute length? Would it be (top diagonalish length+bottom diagonalish length)/2 or only the bottom (or maximum) length in the direction of wind? Thank You

[@zooeyglass1780]

Thank you very much! Very helpful, but I've got a question. Can I do the same thing using different materials? For example, use water instead of air. Am I right if I think that to do this I need to find water in the material database and choose it as the material in material -> fluid section?

[@AdvancedEngineeringTutorials]

Yea that is the right approach.

[@naldofrasco1467]

Good attempt, but you have neglected to input your reference values and therefore get an incorrect Drag Coefficient.

[@AdvancedEngineeringTutorials]

First of all, thank you for watching and thank you for your comment. The goal is to show how to extract drag coefficient here. But please explain more, so all of us can learn. This kind of discussion is very useful for all of us, not only learn the software, but also fluid dynamics. Please explain more in this regard. Thank you.

[@naldofrasco1467]

​@@AdvancedEngineeringTutorials Go to the Reference Values tab and in there you need to input the frontal area of your truck, which you can compute in the Reports->Projected Areas tab (X-direction in your case)

[@AdvancedEngineeringTutorials]

Thank you for your comment, Sure, that is a good point. We can also divide manually later. However, this is a great point and I really appreciate your attention and again watching our videos.

[@kabirjungadhikari2357]

naldo frasco, could you tell me what values should i put for this?

[@alcatraz3021]

Thank you so much!!!

[@muhammadimranbinsharolniza7147]

Hi may i know where to set the correct reference value? Can you make a video explaining it thanks :)

[@Mr.T-Drone-Pilot]

You need to set the reference values to calculate Cd. Your cd is 500 ? Model Year Cab Style Projected Frontal Area (m2 ) 2015-2020 Regular Cab 2.94 2015-2020 SuperCab 2.97 2015-2020 SuperCrew 2.98 2021-2024 Regular Cab 2.97 2021-2024 SuperCab 3.01 2021-2024 SuperCrew 3.02

[@alioztemel3091]

Hi. When I click the initialize button there is not write anything in the console. what would be the reason?

[@AdvancedEngineeringTutorials]

It is very hard to tell.

[@pschoee]

If You start as a hybrid initialize , you will see in the console martian

[@stanislasflipo7214]

I'm trying to simulate a bottle but for the inflation , when I select all by control A and then desulect manually the external face, Ansys says no selection when I apply. Do you have any idea about what's wrong ? Thank you for the tutorial

[@AdvancedEngineeringTutorials]

Thank you for watching and thank you for your comment. If the wall thickness is zero, or you only have the domain as the fluid inside the bottle, that could be the case. Please be more specific, may be an image or related publication, then I can help better.

[@JUANCRUZ-yx6wu]

Muchas gracias por el tutorial

[@AdvancedEngineeringTutorials]

Thank you for watching and thank you for your comment.

[@imranebennageh7592]

Good tutorial.. I'm just searching how to set up the reference values but I can't find any good tutorial on that to get reliable lift and drag coef

[@shannybabayaga]

Thank you king

[@yavuztankirik6553]

thanks for the tutorial of yours first of all. Secondly, I have master degree thesis and wanna clear up it to you. Could you help me out for doing it in Anysis ? Wait for your support. Thanks a lot.

[@AdvancedEngineeringTutorials]

What is the project you are working on?

[@yavuztankirik6553]

@@AdvancedEngineeringTutorials I have sent details to your [e-mail] e-mail. Thank you so much and please check it.

[@AdvancedEngineeringTutorials]

@@yavuztankirik6553 I will reply soon, I am very busy these days.

[@yavuztankirik6553]

@@AdvancedEngineeringTutorials ok. I am waiting for your turn back. Thanks again for your attention.

[@yavuztankirik6553]

@@AdvancedEngineeringTutorials thanks a lot. Wait for your answer 👍

[@pelosmarquez8157]

How do you define the area? Where is the cell to put it? I can’t find de option to put the area. Please 🙏🏻

[@pratik2583]

In drag coeff wall sections; I don't find my model body in wall zones. Encloser wall and other walls(wall11,12,5 wall shadow) are only present. Pls help

[@AdvancedEngineeringTutorials]

could you please explain more?

[@pratik2583]

@@AdvancedEngineeringTutorials ok. I have named my body as "X". Encloser as "Y". I want to calculate drag coeff of my model. I then go to report definations- forces- drag, as shown. In here, at the "wall zones" section , I can see encloser "Y", and some other names such as wall 13, wall5, wall shadow.....but I cannot see model name" X"

[@AdvancedEngineeringTutorials]

@@pratik2583 did you create a name selection in meshing for the target bodies? or walls? for example you can select body X in the meshing, create name selection (shortcut is N) then you will see with that name in the Fluent. You can do the same for walls. Also make sure that in the design modeler, make two bodies one single part, in that case, the interfaces are defined automatically in Fluent. Please let me know if that worked.

[@pratik2583]

@@AdvancedEngineeringTutorials sure...I'll let you know. Thanks for the help.

[@atillasonmez5187]

great tutorial

[@hoangphong6488]

Hello, I have a problem, calculate drag force under water, can you show me how to adjust the parameters about simulation.

[@AdvancedEngineeringTutorials]

could you please be more specific?

[@hoangphong6488]

@@AdvancedEngineeringTutorials helllo, I have a problem, can you find the point of drag fore.

[@AdvancedEngineeringTutorials]

@@hoangphong6488 Hi, the drag force is a distributed force. What do you mean by the point of the force? could you please explain more?

[@nabilallouche8945]

Thank you for information I need some help I couldn't get results when I simulat geometry in open channel flow can you help me sir ?

[@adamdude]

Does this drag coefficient take into account area? I'm getting numbers that seem fairly high

[@AdvancedEngineeringTutorials]

No, you need to define the area in the reference values.

[@MuhammadAhmad-oz4fq]

Hey there you made such a excellent tutorial on CFD my project is going well but I want to ask about Cd graph as in your video the Cd value is about 510 which is very high but when we are considering in real case for example a sedan car has 0.20 to 0.34 Cd value why this software shows much larger value. is there any solution I have issue in it

[@ruthrakumaar1264]

The maximum cl value is 1, for a total aircraft (airbus) the cl is 0.5, but when u run cases in ansys it shows cl value like some values above 1( upto 50) which is completely wrong.

[@herkdaniel807]

You have to give reference values like "Area" and "Length". He forgot to do that in the video. If you define the correct reference values, then the Cd and Cl values going to be correct.

[@mohammadaziemkhalid8264]

Can i calculate the drag and lift force for wig craft using this step?

[@smegletonthethird842]

I have a question about the force vector. is the 1 and the 0 representative of "on and off" or is this corresponding to where you would like the lift and drag to be calculated from?

[@dannysimon1686]

Think of it like a unit vector. If the vector is defined such that x = 1 and y and z both equal 0, the vector would point in the positive x direction

[@Izumi_-de7jl]

yeah they are the cosine values

[@egeerdogan7906]

My fluent launcher is not same as yours and all the videos i watch So what is wrong and how can i see it like yours thank you ..

[@AdvancedEngineeringTutorials]

Thank you for watching and thank you for your comment. What is you ANSYS version?

[@tolgat.9352]

Hi, I used 'Von Karman nose cone' and I found 0.42 drag coefficient. Is that true solution? (I used Fluent (CFX))

[@azooz05030]

Can I calculate drag force for boat in same way?

[@AdvancedEngineeringTutorials]

Thank you for watching and thank you for your comment. Yes, make sure to define the reference area correctly.

[@likelike344]

Can't really hear you with all the audio set to max :/

[@AdvancedEngineeringTutorials]

Sorry about that.

[@galearobert1289]

Amazing

[@azooz05030]

You select lift coefficient why? I want calculate lift force no lift coefficient

[@AdvancedEngineeringTutorials]

You can choose force for calculation.

[@azooz05030]

@@AdvancedEngineeringTutorials Thank you

[@ЕвгениГеоргиев-т1я]

Ansys CFD can calculate Cd and Cl for real?

[@ramgupta7697]

Anyone know how Can we calculate pressure force and viscous force in Ansys for each run time? Any kind of reply will be helpful.

[@mahiravc6171]

Firstly thanks for tutorial, it helped me a lot. But i have a question about underwater analysys. I need to calculate the pressure around the underwater vehicle. Rov wil be dive 400 meters. My questşon is what will be the reference values for doing this analysys? I mean how can i i define the 400 meters pressure? Do i have to make this analysys trasient or steady? Thank you.

[@AdvancedEngineeringTutorials]

Thank you for watching and thank you for your comment. Steady should be okay, and you can define pressure far field or define the pressure in the reference value.

[@henrychan720]

You know the UI is bad when the devs decide a console at the bottom for the users to type in commands is more useful than the buttons.

[@AdvancedEngineeringTutorials]

Thank you for watching and thank you for your comment.

[@anujpatil7785]

I want to do analysis of Tesla model s provide contact

[@MARIF-uv4fv]

Cd is incorrect mate.

[@satyamshukla33]

At least show the basic calculation with reference values