 We are going to begin the hands-on session on K omega and this session will be Conducted by mr. Arbushan once again, so Arbushan if you're ready you can start Okay, let's start the nice hands-on session using spoken tutorial So till now, I think you have done the hands-on session on pipe flow simulation This is added on top of it now you simulate The same pipe flow, but you add turbulence modeling on it So I'm providing link for that Spoken tutorial in the chat Just follow it and if you have some doubt Just put on the chat Yes For me this is showing the missing destination file or brand after home other downloads Sorry Yeah, you can say it That is because you are your own directory Yeah, it is in download we have to extract it you're missing the Period after like the destination is not being specified Well, you're first extracted it is not You're extracted so one this is done you have to copy this Go inside So you have to copy it to extract this as well And a copy only yeah first extract them extract K omega or keeps it up Let me sit. I'm not able to see you skin Okay, you can copy this to your download Yeah, you can copy this here, or you can just copy it at your run also Now go to your terminal I'm gonna provide you some command They saw me See I provided you a command that that way it will Mount your C drive and then you can go to your download Directory, but you have to replace that reg me with your CPU name Got it After cp I have to No, first you have to go to the directory you would right now you are in the turn directly you have to go to the Directory which contains your files that is k epsilon and k omega Or you can do this one thing. Uh, it is this Type it is all of them type explorer dot exe space dot this Check the spelling. It's it is mistake explorer You have Yeah space dot Dot patienter Okay, now copy those file here I think it is already copied. You just have to paste it. Okay. Now you can access this file From here from your run thing only You can use the terminal now Okay Now you can if you do cd k epsilon you will go inside k epsilon. Okay Okay Neha, can you present your screen? Okay, I think you have opened the wrong Uh, this thing terminal or root instead of ubuntu 18.05 You might have been installed multiple version of Close this and go to the search bar. Uh, close this thing. Uh, once again, go to the close this thing Close both of them Go through the search bar type ubuntu So I see you have only one Ubuntu okay You got it. Were you properly able to do other tutorials? So yesterday I did but not today Okay, what happened today? Today when I opened it's opened like this only Okay This is actually a root. This is a different WSN Okay You might have installed more than one WSN in your system No, sir. Only one Only one. Okay. Yes So, uh, are you able to carry out the tutorials in this? No, sir Do you have openform installed here? Yes, I have installed it So if I'm writing this Now I am now you should be. Yeah, okay Now you should be able to Use it, I think But permanently I'm not getting this Okay Yes, if I close it and again open it, I will be in root only Okay, it's okay. If you are able to use it like this, then you can Okay, okay Sir in spoken tutorial, it is saying download code files. How can you download code files, sir? Uh, go to the Website and on the right side at the bottom Click on code files. You just have to click on it. I need to download it for you Uh, hello, sir Yes Uh, sir, uh, after typing notepad.exe system blockmask direct It is coming. Uh No such file or directory is formed So are you sure you have typed it correctly? Come on Spelling in everything you can present your screen I think the m should be lowercase Or you can just type like block and then Hit tab and it will auto-complete it for you Yeah, if you want to Uh, do less spelling mistake, you can just use tab Instead of typing the whole command. So if you press tab It will complete it for you, mother I'm fine, but it is not happening Uh, let's see the d is capital Sir, how to copy a command here if I'm right clicking It is not happening You can press the up arrow and Uh, I mean you can just press the the up arrow button in your keyboard Um, it is giving us wrong but nothing The m is capital, uh again Yeah No pressing tab Or maybe just type ls system Let's see what's in there Just type ls, yeah Yeah, you need to go into k epsilon and then Uh cdk epsilon Yeah, I mean you can stop presenting now. I think it's the same commands. No, it should work Do the student who have completed the tutorials can they read it Hello Are you speaking to this? Uh, yes, sir, but I am typing the second code, sir, but it's showing no file cp dot It's downloaded because you have not copied it. Uh, don't worry. I'll teach you how to do it now Okay So even if you Uh, we don't able to complete the tutorial. Don't worry I'm going to show you guys how to do it now You guys can just follow me and if you have any, uh question Just ask us in the chat So I have downloaded the code file From the website There are three code files You don't need to do all of them. But if you have done it, then nice Since the previous tutorial was on k omega. I'm going to use just the k omega one To show you guys So I have extract this extracted this k omega And now it is in my download Uh folder, okay, and this download folder is in my Windows However, in my double asl. I am Incitement double asl now Here is no download or any such thing in my uh double asl So I have to physically go to this k omega directory if I want to simulate this So for this you have to use this command Uh cd space slash mnt mnt stands for mount So what it will do it will mount my c drive So inside my c drive Which is here And inside my users And inside my pc name that is rig me You will find that there is a A download folder Here Download folder So you just have to give path of this C user take me download After the mount So when I click on that and when I give this command and press enter This makes you that you might not have the name rig me Your pc might have its own name And after entering this command now i'm in my download directory Now if I do ls There is one something in my uh Download So I don't want to see that Uh, but I do know that I have already copied my k omega file in my download So I'm just going to do cd and go to k uh k small o okay k omega So when I press enter I'm inside my k omega file Now if I do ls I have zero constant and system in my k omega so Here now what I'm going to do is I'm going to show you guys the block mistake So notepad third exe system block mistake So We have a two block And these are the vortices And in each one of the block we are using expansion ratio so that we get Uh grading in our mess That has a fine number of mess near the wall And we have these are the boundaries lower wall upper wall inlet and outlet Since this is a 2d simulation our front and back is kept empty And we are not using most passfare Most passfare is used to combine two different block If you if it doesn't share the same vortex Uh, this is for advanced thing, but we don't we we are not using this here right now and Motion just a minute. This is Joseph. You said just now you said for 2d. We are keeping what is the condition in black mesh for 2d Since we're doing this empty Empty which are the phases we need to keep it empty? Uh, the the phases that is perpendicular to us Like okay, okay So let's go to the turbulence properties So initially in turbulence properties, uh, when you are doing laminar simulation Here there would be simulation type laminar and you there would not be anything Even if there were these Parameters open foam will would simply ignore this Now we have r s and inside r s we are using modal k omega Okay, i'm going to close this file Now let's look at the uh zero fine So inside zero we have u for velocity k not n omega so Previously we used to provide boundary condition for only u and p now we need to provide one for k not n omega as well So let's open one of them So here is the uh boundary condition for k which is which stands for turbulent intensity and This value you can calculate uh through empirical relation This is the more information is provided on our Spoken tutorials here is an additional reading material section So if you go to the same website and scroll down You will see code files then script then slides and at the very bottom you will see additional reading materials From here you can find out how we calculated this intensity Thing and outlet is kept zero gradient And we have we are providing some wall function in upper and lower wall And as usual front and back is kept empty because this is a 2d simulation now for not We have just using calculated. So based on the value of uh k, it will calculate the not From that value And on the wall we are providing not k wall function Sorry, could you tell me what is this n ut? So this is a wall function That we are providing here No, this this variable n ut this folder Any defense for turbulence viscosity nu means nu the viscosity mu t So in the while solving k omega If you have if you remember the lecture that was taught to you previously So do we are solving for omega transport equation for omega and uh transport equation for mu t So it is just that that parameter Okay, thanks And similarly for omega Again, we are using empirical relation to calculate this value. You can refer to the additional reading material And uh in the previous lecture also you were taught how to calculate this very value, I think And In outlet we are giving zero gradient and we are using wall function in upper and lower wall And front and back is kept empty Okay, now I will run the simulation first. I will do block mist This would miss uh my geometry Now I'm gonna do uh Simple form So my simulation is running I'll just wait for some time to try to complete Okay, my simulation has completed. So to view the result first, I'm going to create my dummy file. Let it result That form And if I do explorer dot exe Dot this time it should open my download and k k omega that is inside download because I'm in that directory So here I I'll just click on this thing And when I click on apply You can see our geometry And this is our pressure But this is at time step 50. Okay Now we'll go to time step 100 I will click on this thing. Uh, this is called rescale to data range. Whenever you have a Simulation that has different Ranges of values. So in initially at 50 our range is different and at Thousand or the range minimum maximum value of pre is different So it will rescale my data according to the minimum and maximum of that time step Now this is my pre profile and this is my u profile. I'll just zoom in so that you can see it clearly Here again, I think I have to do the rescale data today. So it is already done So let's view the profile. I'm going to click on this thing. Uh plot over line And click on y axis And then click on apply So if you want to see you magnitude, this is the you magnitude so You may have noticed that in case of laminar flow, our profile was parabolic But now we don't have parabolic. We have something else So when there is a turbulent flow, this is the profile that we get And similarly if you want to see p This is the profile that we get for pressure Now I'm actually viewing my, uh Profile at the middle and just assuming that uh, the flow is fully developed by middle Uh, if you want to know more about where the flow is fully developed or not, uh in the spoken tutorial, it was mentioned So This is the end of the spoken tutorial. Uh, if you were not able to follow the spoken tutorial, uh, this person will be provided to you can go back again and Do the same time at your leisure Meanwhile, if you have any question you can type in the chat box or ask us Sir, uh In laminar and turbulence, which one is more realistic? Uh, I don't understand what do you mean by realistic because both You saw that both have having the different, uh velocity profile, right? Okay, it depends on your Reynolds number So if your Reynolds number is very low, you don't need to carry out turbulence Simulation the laminar simulation is sufficient and it is accurate But if your Reynolds number is very high, then your laminar Simulation will not be accurate in this case. You will need to do turbulent simulation So for very high Reynolds number, whether the simulation will stop in between or it will some it will give some garbage value Uh, what do you mean by stop in between like like suppose, uh, we are submitting the simulation with very high Reynolds number With laminar model not the turbulence model. So in that case, uh, whether the laminar model will work or not In that case, uh, depending on your problem if your problem is very, uh, like simple It may work, but the value will be garbage that you are just doing garbage in garbage out So if your problem is complex, then what happens is that you will not get convergence Your simulation The rigid value of the residual you should check it will be very high relatively higher than the one in laminar case Someone is asking how to get professor profile drop. Okay. I'm gonna show it Okay, I hope my screen is uh visible to everyone So this is my pressure. So if I want to, uh, find out the how my pressure changes gradually along the Uh, flow direction, I'm gonna again click on plot over line and Click on uh, but this time instead of clicking on y axis I'm gonna click on x axis because my x axis aligns with my flow direction So if I click on x axis and click on apply I'm going to remove, uh Once up useless parameters that I don't want to see because I only want to see pressure Uh, okay So this is how my Pressure drops so add my inlet pressure is high and you can see it is dropping somewhat linearly And it reaches the value of zero I think zero is the pressure that we provided at the outlet So based on that it is actually calculated calculating the pressure at inlet and other Uh part in the domain I hope that answers your question Hello, uh, just I have a question regarding the residuals like in the morning session. Okay, so do you uh The maximum number of iterations in one of the demonstrations were put as 10 Yeah, how do we fix that number like 10 some trial and error or So yeah, it's a trial and error by default the maximum number of iteration is actually thousand Uh, it was put in just only for the demonstration So if you put 10 or 5 that is a very low value So what happens is that your in iteration will complete faster The result that will you will get will be a garbage out in in such case So it was only for the purpose of demonstration Uh, generally By default it is at thousand and thousand is sufficient So before thousand it should converge Does that answer the question? Yeah, okay. Thank you. Thank you so much Okay, now, uh, I will close this session Uh pilot yes Yes, thanks a lot