Although they are some simple concepts, they can be a bit tricky to deal with, especially if you are new to the fluid concepts. Thank you for the video, really clear and brief :) Perfectly summed!
Thank you, it is clear for definitions. But I still cannot understand that kind of question, 'what is the streakline at a time point ', I don't know how to sketch it.
Hi Prof. Dr. Tahsin Engin, I use: microsoft paint to write on bamboo wacom tablet to write the stuff obs to record screen adobe premiere pro to edit/export video
Yeah, cool, but one question though. The points you have connected in your streamline example aren't common points where all the particles in question passed
[2:51 ahwww, ohkayy. Streakline's defnition and illustration on wikipedia were way too technical for me. I think i got it now. Thanks en.wikipedia.org/wiki/Streamlines,_streaklines,_and_pathlines
i know this might be dumb and maybe nobody will respond, BUT, every single time im in the shower, ive been a bit of a weirdo and observed for many many years that the water droplet when it travels down, if it falls into another already previously travelled path by another water droplet, it will more likely go through this path, except sometimes depending on angle etc, it takes a few seconds for that water droplet to push through into that streakline... MY QUESTION IS, is that an example of a streakline or have i confused the concept? CHEERS
Hey mate it's been 4 months here is what I think about it. So the streakline is a path created by fluid molecules that pass through the same point like after sometime. For your case if we assume droplets as fluid molecules and let's assume the 🚿 (shower head) as their starting point. These two particles they travel irrelevant paths at first than they intersect. So the streakline I believe is a curve that connects particles at different times. But after a while these particles are getting together forming a new solo particle therefore yes I guess they form a streakline which is unsteady. Wish I could have drawed you these but heck idk. Hope this helps
@@henrycoldrain8151 One modification needed. A streakline is the line formed by the these particles at same time ( not at different times), once they have passed through shower (and also takes certain time to follow their respective paths before meeting (in case, you think they will meet)) because a streakline is the locus of the points and a locus is formed by joining the multiple points and is perceived to be joined at a single point of time. So, (after leaving the shower and before meeting), at any instant, these particles would have some distance( in between them) and that is shown by an imaginary line which is streakline. Hope this helps!! ( I wish I could draw and show it)
You are right except for one condition and that is the single particle should not form loop, otherwise the path followed by the particle would be only pathline, not a streamline.
A streamline refers to a particular instant of time whereas a pathline involves the variation of time, since a fluid particle takes time to move from one point to another. For example, let us say, a particle has travelled from t= 0 second and to t=5 seconds. Obviously, during these 5 seconds, it will change its position. But the flow parameters ( like velocity) may change (as for unsteady flow) or may not change (as for steady flow) within these 5 seconds. So, for pathline, the key factor is the duration of 5 seconds from initial to final point of time. (And to see whether the change of fluid properties is taking place or not). For streamline, the key factor is the instant of time i.e., at instant t= 0 second , we check what is the velocity ( and other flow parameters) and this will be same throughout the streamline at that instant only and at instant t= 5 sec, we again check the parameters ( which may or may not be different from those of the values at t=0 second). So, for streamline, we are not interested in whether the flow parameters are changing or not within these 5 seconds, we are only concerned with the point of time ( with position of a single particle at different times or the position of different particles at same time along a streamline) viz., At t=0 sec, t= 5 second. (Also, you can take for t=1,2,3,4 seconds as the conditions demand...) Another difference between streamline and pathline is that the streamlines do not intersect each other (and also a particle traversing can't form a loop itself), otherwise at any instant, a single particle will have two different velocities which is never possible ( since the instantaneous velocity of a particle is uniquely defined) While two pathlines can intersect each other or a single pathline itself can form a loop because under certain conditions, even a same particle can arrive at a same location at different instant of times. Hope it clarifies !!
Lol, he said something incorrect. At 1:21, he says streamline changes with time in an unsteady flow, but that is not true. Unsteady flow can also mean that the speed of particles at each position is changing, but their direction doesn't change. In this unsteady flow case, streamline doesn't change with time as the tangent points in the same direction.
Hey Rohan thanks for your input, I think you were referring to 3:28, I kinda forgot about this video but at that timestamp I said streamline "may" change shape with time in unsteady flow, which is including the possibility that the streamline may not change.
Thank you, it is clear for definitions. But I still cannot understand that kind of question, 'what is the streakline at a time point ', I don't know how to sketch it.
Although they are some simple concepts, they can be a bit tricky to deal with, especially if you are new to the fluid concepts. Thank you for the video, really clear and brief :) Perfectly summed!
You made the concept clear. Out of so many videos in RUclips, I found yours is helpful...
Keep Doing. Thank you!
Thanks bro, my teacher just wrote the definitions and then moved on to next topic.
then why didn't you stop him/her and ask?
what a mean thing to do ngl
Pretty sure he/she didn't quite understand it clearly either
Thank you so much! My professor was describing this too damn abstract, when it can be all soooo simpel...
Perfect explanation. Need more videos
The explanation is clear and quite easy to understand. Thanks a lot.
The best answer I have ever seen , thanks :)
Yeah, you do explain amazingly!
Better than any book,thank you so much
Best explanation ever! Well done & tnx a lot.
Thank you, it is clear for definitions. But I still cannot understand that kind of question, 'what is the streakline at a time point ', I don't know how to sketch it.
Clear explanation. Which app are you using to create these videos?
Hi Prof. Dr. Tahsin Engin, I use:
microsoft paint to write on
bamboo wacom tablet to write the stuff
obs to record screen
adobe premiere pro to edit/export video
legend, thank you
Well explained!! Thank you
I found it very helpful. Thanks.
Beautiful explanation
awesome explanation
Real helpful mate! Keep up the good work!
Thank you so much
Concise and well explained. Thanks
Hey Thanks !!!
Nice explanation
Yeah, cool, but one question though.
The points you have connected in your streamline example aren't common points where all the particles in question passed
Nice explanation... Thank you!!
[2:51 ahwww, ohkayy.
Streakline's defnition and illustration on wikipedia were way too technical for me. I think i got it now. Thanks
en.wikipedia.org/wiki/Streamlines,_streaklines,_and_pathlines
i know this might be dumb and maybe nobody will respond, BUT, every single time im in the shower, ive been a bit of a weirdo and observed for many many years that the water droplet when it travels down, if it falls into another already previously travelled path by another water droplet, it will more likely go through this path, except sometimes depending on angle etc, it takes a few seconds for that water droplet to push through into that streakline... MY QUESTION IS, is that an example of a streakline or have i confused the concept?
CHEERS
Hey mate it's been 4 months here is what I think about it.
So the streakline is a path created by fluid molecules that pass through the same point like after sometime.
For your case if we assume droplets as fluid molecules and let's assume the 🚿 (shower head) as their starting point. These two particles they travel irrelevant paths at first than they intersect. So the streakline I believe is a curve that connects particles at different times. But after a while these particles are getting together forming a new solo particle therefore yes I guess they form a streakline which is unsteady.
Wish I could have drawed you these but heck idk. Hope this helps
@@henrycoldrain8151 One modification needed. A streakline is the line formed by the these particles at same time ( not at different times), once they have passed through shower (and also takes certain time to follow their respective paths before meeting (in case, you think they will meet)) because a streakline is the locus of the points and a locus is formed by joining the multiple points and is perceived to be joined at a single point of time. So, (after leaving the shower and before meeting), at any instant, these particles would have some distance( in between them) and that is shown by an imaginary line which is streakline.
Hope this helps!!
( I wish I could draw and show it)
Can you please tell which software you are using to draw?
Great Bro .. u doinG a Good joB
It helps me a lot.thanks
Very good video
When a movement of single-particle is tracked, the pathline and streamline are the same in both steady and unsteady cases. am I right?
You are right except for one condition and that is the single particle should not form loop, otherwise the path followed by the particle would be only pathline, not a streamline.
But Streamlines do not track the movement of one particle, but rather show the current velocity field of the fluid at one moment in time.
Can someone please tell me whats the meaning of streamline? Why do we need it apart from pathline ?
A streamline refers to a particular instant of time whereas a pathline involves the variation of time, since a fluid particle takes time to move from one point to another.
For example, let us say, a particle has travelled from t= 0 second and to t=5 seconds. Obviously, during these 5 seconds, it will change its position. But the flow parameters ( like velocity) may change (as for unsteady flow) or may not change (as for steady flow) within these 5 seconds. So, for pathline, the key factor is the duration of 5 seconds from initial to final point of time. (And to see whether the change of fluid properties is taking place or not).
For streamline, the key factor is the instant of time i.e., at instant t= 0 second , we check what is the velocity ( and other flow parameters) and this will be same throughout the streamline at that instant only and at instant t= 5 sec, we again check the parameters ( which may or may not be different from those of the values at t=0 second). So, for streamline, we are not interested in whether the flow parameters are changing or not within these 5 seconds, we are only concerned with the point of time ( with position of a single particle at different times or the position of different particles at same time along a streamline) viz., At t=0 sec, t= 5 second. (Also, you can take for t=1,2,3,4 seconds as the conditions demand...)
Another difference between streamline and pathline is that the streamlines do not intersect each other (and also a particle traversing can't form a loop itself), otherwise at any instant, a single particle will have two different velocities which is never possible ( since the instantaneous velocity of a particle is uniquely defined)
While two pathlines can intersect each other or a single pathline itself can form a loop because under certain conditions, even a same particle can arrive at a same location at different instant of times.
Hope it clarifies !!
@@ANUJKUMAR-pf2fb thank you for your great explanation, i already passed the class and understood the concept really well ,thank you
@@EmreErdogan99 You're welcome
Thanks
thank you
thank u sir, u cleared my doubts.👍
you're welcome, I'm glad this cleared your doubts
Thankyou, you are talented in explanation. very helpful in Fluids Mechanics.
thank you for your very kind comment, hope you have a great day :)
Awesome 😃
nice job
thanks
thank u so much
good job
Nice but i still couldn't understand streaklines
very good video with powerful explanation
Woow
Thanks
Lol, he said something incorrect.
At 1:21, he says streamline changes with time in an unsteady flow, but that is not true.
Unsteady flow can also mean that the speed of particles at each position is changing, but their direction doesn't change.
In this unsteady flow case, streamline doesn't change with time as the tangent points in the same direction.
I am so jobless right now
Hey Rohan thanks for your input, I think you were referring to 3:28, I kinda forgot about this video but at that timestamp I said streamline "may" change shape with time in unsteady flow, which is including the possibility that the streamline may not change.
still i have issue with understanding these concept
good
you are god
thank youuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
한국인?
The explanation of streakline is not clear, it is better to figure out that the streakline is relative to time.
I don't understand clear my doubts ❓
Content is good but please improve ur handwriting
worst explain
Thank you, it is clear for definitions. But I still cannot understand that kind of question, 'what is the streakline at a time point ', I don't know how to sketch it.
nice job