Pathline and Streamline problem

  • Thread starter Abigail1997
  • Start date
  • Tags
    Streamline
In summary, the student is trying to find a solution to a homework problem that they have only seen once before. They are aware of what a velocity field is, but do not understand more complicated concepts such as the streamlines. They are able to find the streamlines for t=0, but are not sure how to find the streamlines for t=1.
  • #1
Abigail1997
6
0
Screen Shot 2016-07-27 at 17.55.55.png
1. Homework Statement

As above

Homework Equations


Not sure.

The Attempt at a Solution


I've only ever seen one of these problems and it was in the form of V=Axi-Ayj, so much simpler and even then it was poorly explained by the lecturer. I understand what a velocity field is but not much more.
 
Physics news on Phys.org
  • #2
Hi, Abigail, :welcome:

Try A=0 to get started. The velocity vector at point ##(1,1)## is ?
 
  • #3
statement, all variables and given/known data
I have completed question a, getting e^(t+((t^2)/4)) and e^t respectively and found the streamline for t=0, getting x=Cy, c being a constant- but am totally out of idea for finding it when t=1. I have been told the answer is e^3/2 but not sure how to get there

Homework Equations


dx/u=dy/v[/B]
first paragraph counts as an attempt at solution, I would say. (Choosing C as parameter is unfortunate, though, if the problem statement already has a C.)
Can't guess what u and v are; the components of ##\vec v## ?
You found the streamlines at t =0 from ##\vec v = Bx\hat\imath + Cy\hat\jmath##
Aren't the streamlines for t=1 given by simply substituting t=1 and doing the same thing ?
 
  • Like
Likes Abigail1997
  • #4
BvU said:
first paragraph counts as an attempt at solution, I would say. (Choosing C as parameter is unfortunate, though, if the problem statement already has a C.)
Can't guess what u and v are; the components of ##\vec v## ?
You found the streamlines at t =0 from ##\vec v = Bx\hat\imath + Cy\hat\jmath##
Aren't the streamlines for t=1 given by simply substituting t=1 and doing the same thing ?

Yeah I realized that and changed it to D :) correct, u and v represent the x and y components of V. As for the subbing in t=1, that's what I thought but I cannot seem to get the correct answer (e^3/2) but I'm probably making a silly mistake somewhere and just can't see it
 
  • #5
Check the non-moving dashes in the first picture here (watch out for headaches).
These dashes at fixed grid points you can draw for t=1 in your exercise. They should suggest the ##e^{3\over 2}##
 
  • Like
Likes Abigail1997

1. What is the difference between a pathline and a streamline?

A pathline is the trajectory of a single fluid particle over time, while a streamline is a line that is tangent to the velocity vector at each point in the flow field. Essentially, a pathline shows the actual path of a particle, while a streamline represents the direction of flow at any given point.

2. How are pathlines and streamlines related to each other?

Pathlines and streamlines are related because they both show the movement of fluid particles in a flow field. A pathline can be thought of as a collection of streamlines, with each streamline representing the direction of flow at a specific point in time.

3. What are some applications of pathline and streamline analysis?

Pathline and streamline analysis can be useful in many fields, such as fluid dynamics, aerodynamics, and oceanography. It can help in understanding and predicting the behavior of fluids in various systems, such as air flow over an aircraft wing or ocean currents.

4. How is a pathline and streamline problem solved?

To solve a pathline and streamline problem, one needs to first define the flow field and initial conditions, such as the velocity of the fluid particles at a certain time. Then, mathematical equations, such as the Navier-Stokes equations, can be used to calculate the pathlines and streamlines of the particles in the flow field.

5. What are some limitations of pathline and streamline analysis?

One limitation of pathline and streamline analysis is that it assumes the fluid is incompressible and has constant viscosity, which may not always be the case in real-world situations. Additionally, it does not take into account factors such as turbulence and viscosity gradients, which can affect the accuracy of the results.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
9
Views
5K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
3K
  • Differential Geometry
Replies
2
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
Replies
1
Views
2K
Back
Top