Is the Eulerian View Valid for Unsteady Flows?

Thread starter mech-eng
Start date Mar 31, 2017
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Lagragian

In summary, Eulerian and Lagrangian views are two different perspectives used in fluid mechanics to study the motion of fluids. The main difference between them is the frame of reference they use to describe the fluid motion. The Eulerian view measures fluid properties at fixed points in space, while the Lagrangian view measures properties at specific points in the fluid that move with the flow. Both views have their own advantages and can be used to study the same fluid flow, but the Eulerian view is more commonly used for its detailed analysis. The equations of motion also differ between the two views, with the Eulerian view based on conservation laws at fixed points and the Lagrangian view based on specific fluid particles. These views have practical applications in fields

Mar 31, 2017

mech-eng

Is Eulerian view valid when the flow is unsteady? I think Eulerian view is valid only for steady flows because the points in the flow domain should be with constant velocities.

Thank you.

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Mar 31, 2017

boneh3ad

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Neither the Eulerian nor Lagrangian descriptions of a flow field care whether the flow is steady or not. Both are valid for unsteady flows.

1. What is the difference between Eulerian and Lagrangian views?

Eulerian and Lagrangian views are two different perspectives used in fluid mechanics to study the motion of fluids. The main difference between them is the frame of reference they use to describe the fluid motion. In the Eulerian view, the fluid properties are measured at fixed points in space, while in the Lagrangian view, the properties are measured at specific points in the fluid that move with the flow.

2. Which view is more commonly used in fluid mechanics?

Both Eulerian and Lagrangian views have their own advantages and are used for different purposes. However, the Eulerian view is more commonly used in fluid mechanics as it allows for a more detailed analysis of the fluid flow in a fixed reference frame.

3. How are the equations of motion different in Eulerian and Lagrangian views?

The equations of motion for a fluid in the Eulerian view are based on the conservation laws of mass, momentum, and energy. These equations are expressed in terms of the fluid properties at a fixed point in space. In contrast, the equations of motion in the Lagrangian view are based on the conservation of mass, momentum, and energy for a specific fluid particle as it moves through space.

4. Can both views be used to study the same fluid flow?

Yes, both Eulerian and Lagrangian views can be used to study the same fluid flow. However, the results and insights obtained from each view may differ due to the different perspectives and frames of reference used.

5. What are the practical applications of Eulerian and Lagrangian views?

Eulerian and Lagrangian views are widely used in fields such as fluid mechanics, atmospheric sciences, and oceanography to study and analyze fluid flows. They are also used in various engineering applications, such as aerodynamics, hydrodynamics, and heat transfer, to design and optimize systems that involve fluid motion.