Plotting Stream lines (Fluid Mechanics)

In summary: Create a grid of x and y values using the "meshgrid" function.c. Calculate the stream function using the given equation.d. Plot the streamlines using the "contour" function, with the stream function as the input.2. Flow over an inclined plate:a. Define the variables q0, c, and a (you can choose any values you want).b. Create a grid of ζ and η values using the "meshgrid" function.c. Calculate the stream function using the given equation.d. Plot the streamlines using the "contour" function, with the stream function as the input.In summary, to plot the streamlines for these two types of potential flow solutions, we
  • #1
kingjames
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Plotting Stream lines! (Fluid Mechanics)

Homework Statement



In this project you are required to investigate two types of potential flow solution:
a. Flow over a vertical plate (flow is perpendicular to the plate i.e.  = 90)
b. Flow over an inclined plate ( = 135).


You are required to do the following:
1. Find the expression of the stream function for these types of flow.
2. Derive the expression for the velocity profile.
3. Sketch the streamlines for different values of the stream function using your favorite computer software (Matlab, Excel …).


Homework Equations


i found the equations of stream functions for both cases:

Case of a flow over a vertical plate: ψ4 + ψ2 U2(x2-y2+a2) = U4x2y2

Case of a flow over an inclined plate ψ=(-1)/√2 q0 c sinhζ (cos η-sin η)


The Attempt at a Solution



IF u can help me with codes to plot these functions using MATLAB or excel or any other program!
 
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  • #2


Hi there! As a scientist who specializes in fluid mechanics, I would be happy to assist you with plotting streamlines for these two types of potential flow solutions.

First, let's start with the expression for the stream function for each case:

1. Flow over a vertical plate:

The stream function for this case is given by the equation ψ = U∞(x2-y2+a2) where U∞ is the free stream velocity and a is the distance between the plate and the origin.

2. Flow over an inclined plate:

The stream function for this case is given by the equation ψ = (-1)/√2 q0 c sinhζ (cos η-sin η) where q0 is the free stream velocity, c is the chord length of the plate, ζ is the distance along the plate from the leading edge, and η is the distance normal to the plate.

Next, let's derive the expression for the velocity profile for each case:

1. Flow over a vertical plate:

The velocity components can be found by taking the partial derivatives of the stream function with respect to x and y. This gives us u = U∞(2x) and v = -U∞(2y). Therefore, the velocity profile is given by the equation V = √(u^2+v^2) = 2U∞√(x^2+y^2).

2. Flow over an inclined plate:

The velocity components can be found by taking the partial derivatives of the stream function with respect to ζ and η. This gives us u = (-1)/√2 q0 c coshζ (cos η-sin η) and v = (-1)/√2 q0 c sinhζ (-sin η-cos η). Therefore, the velocity profile is given by the equation V = √(u^2+v^2) = (-1)/√2 q0 c √(cosh^2ζ+sinh^2ζ) = q0 c.

Now, to plot the streamlines for different values of the stream function, we can use MATLAB or any other software that allows us to plot graphs. Here's how we can do it in MATLAB:

1. Flow over a vertical plate:

a. Define the variables U∞ and a (you can choose any values you want).
b
 

Related to Plotting Stream lines (Fluid Mechanics)

1. What is the purpose of plotting streamlines in fluid mechanics?

The purpose of plotting streamlines in fluid mechanics is to visualize the flow pattern of a fluid. Streamlines show the direction and path of fluid particles as they move through a flow field, providing valuable information about the behavior of the fluid.

2. How do you plot streamlines?

To plot streamlines, you need to first define a grid or mesh over the flow field. Then, using mathematical equations and numerical methods, you can calculate the velocity at each point on the grid. Finally, you can plot the streamlines by connecting points with the same velocity vector.

3. What information can be obtained from a streamline plot?

A streamline plot can provide information such as the direction and magnitude of the flow, areas of high and low velocity, and the presence of vortices or other flow patterns. It can also help identify areas of potential turbulence or stagnation within the flow field.

4. How can streamlines be used to analyze fluid flow?

Streamlines can be used to analyze fluid flow by providing a visual representation of the flow pattern. From the streamline plot, one can determine the overall behavior of the fluid, identify regions of interest for further analysis, and make predictions about the effects of obstacles or changes in the flow conditions.

5. Can streamlines be used in all types of fluid flow?

Streamlines can be used in most types of fluid flow, including laminar and turbulent flow. However, in certain cases such as highly viscous or non-Newtonian fluids, other methods may be more suitable for analyzing the flow behavior.

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