Comsol-Fluid flow and shear stress

In summary: The discrepancy in the solution may be due to this difference. It is important to consider the correct equation and values when calculating shear stress in fluid flow.
  • #1
baranii2000
4
0
Dear all,

I was trying to calculate the shear stress due to fluid flow inbetween two parallel plates from the velocity profile taken from the middle of the flow channel (along vertical axis 'y') using comsol. The solution i got is two times the analytical solution i have calculated. The analytical equation i have used here is
Tou=viscosity*(Umax/h)

where tou is shear stress, umax is the max velocity
h is half of the distance between plates.

The calculation with velocity profile from comsol is done by

Tou= viscosity*(du/dy)
du/dy, i calculated with excel from the u,y values in the velocity profile.

the velocity profile is parabolic and looks laminar.
is that i am doing something wrong?


Thanks

Arun
 
Last edited:
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  • #2
baranii2000 said:
Dear all,

I was trying to calculate the shear stress due to fluid flow inbetween two parallel plates from the velocity profile taken from the middle of the flow channel (along vertical axis 'y') using comsol. The solution i got is two times the analytical solution i have calculated. The analytical equation i have used here is
Tou=viscosity*(Umax/h)

where tou is shear stress, umax is the max velocity
h is half of the distance between plates.

The calculation with velocity profile from comsol is done by

Tou= viscosity*(du/dy)
du/dy, i calculated with excel from the u,y values in the velocity profile.

the velocity profile is parabolic and looks laminar.
is that i am doing something wrong?Thanks

Arun
For a parabolic velocity profile, if you calculate the velocity gradient at the wall, it is equal to 2Umax/h, not Umax/h
 

FAQ: Comsol-Fluid flow and shear stress

1. What is Comsol and how does it simulate fluid flow and shear stress?

Comsol is a finite element analysis software that can simulate fluid flow and shear stress by solving the Navier-Stokes equations, which describe the motion of fluids, using a numerical method called finite element analysis.

2. What are the main features of Comsol that are useful for studying fluid flow and shear stress?

Comsol offers a variety of features such as built-in physics interfaces, customizable meshing options, and the ability to simulate both laminar and turbulent flow. It also has built-in solvers for various types of flow problems and the option to incorporate user-defined equations.

3. Can Comsol accurately predict fluid flow and shear stress in real-world situations?

Yes, Comsol has been extensively validated and is known for its accuracy in predicting fluid flow and shear stress in various real-world scenarios. However, the accuracy of the simulation depends on the accuracy of the input parameters and boundary conditions.

4. How does Comsol handle complex geometries in fluid flow and shear stress simulations?

Comsol has a built-in geometry modeling tool that allows users to create and import complex geometries for their simulations. It also offers meshing options that can handle complex geometries and generate high-quality meshes for accurate simulations.

5. Can Comsol be used to study the effects of turbulence on fluid flow and shear stress?

Yes, Comsol has built-in turbulence models that can accurately simulate turbulent flow and its effects on fluid flow and shear stress. Users can choose from various turbulence models such as k-epsilon, k-omega, and Large Eddy Simulation (LES) to study turbulence in their simulations.

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