Help with Drag Calculation for Laminar Flow Model

In summary, the reacf() operator in Comsol Multiphysics can be used to calculate the drag force on a stationary, laminar flow model by defining a 'u' vector field and using the operator to calculate the drag force.
  • #1
velisch
2
0
Hi there,

I am working an a stationary, laminar flow model and would like to calculate the drag of that model.
Now the Comsol forum guys suggest to use the operator reacf(u). It is also used in the "Flow over a circular cylinder" tutorial. Does anyone know where to get it from or how to use the reacf() operator?
I have been looking everywhere for this tutorial, asked for help in the comsol forum, read the Comsol guide but I haven't found any useful information.
I am really desperate for help, please.

Appreciate it
 
Physics news on Phys.org
  • #2
. The reacf() operator is part of the Comsol Multiphysics software. It allows you to calculate the drag force on a stationary, laminar flow model. To use this operator, you need to first define a 'u' vector field in the physics interface, which represents the velocity field of the flow. Then, you can use the reacf() operator to calculate the drag force on the model. You can find more information about the reacf() operator in the Comsol documentation.
 

Related to Help with Drag Calculation for Laminar Flow Model

1. What is drag?

Drag is the force that opposes the motion of an object through a fluid, such as air or water. It is caused by the friction and pressure differences between the fluid and the surface of the object.

2. How is drag calculated for laminar flow?

The drag for laminar flow is calculated using the drag equation, which takes into account the fluid density, the object's velocity, its cross-sectional area, and a drag coefficient specific to the shape of the object. This equation is D = 1/2 * ρ * v^2 * A * Cd, where D is the drag force, ρ is the fluid density, v is the velocity, A is the cross-sectional area, and Cd is the drag coefficient.

3. What is a laminar flow model?

A laminar flow model is a mathematical representation of the flow of a fluid that assumes a smooth, non-turbulent flow. This type of flow is characterized by layers of fluid that move in parallel, with little to no mixing between them.

4. How does the Reynolds number affect drag in a laminar flow model?

The Reynolds number, which is a dimensionless quantity that compares the inertial forces to the viscous forces in a fluid, has a significant impact on drag in a laminar flow model. At low Reynolds numbers, the flow is laminar and the drag is directly proportional to the velocity. As the Reynolds number increases, the flow becomes turbulent and the drag increases exponentially with velocity.

5. Can drag be reduced in a laminar flow model?

Yes, there are several ways to reduce drag in a laminar flow model. Some methods include using streamlined shapes, reducing the object's surface roughness, and controlling the flow separation by using vortex generators or other flow control devices. Additionally, reducing the fluid density or velocity can also decrease drag in a laminar flow model.

Similar threads

I Regarding when to consider both laminar and turbulent flow
    • Other Physics Topics
Replies
7
Views
2K
B Beam of air: Extending the range of a fan
    • Other Physics Topics
Replies
17
Views
2K
COMSOL Modeling help (ambient air around a thermoelectric module)
    • MATLAB, Maple, Mathematica, LaTeX
Replies
3
Views
2K
Beyond Viscous Drag, Cavitation, Laminar Flow, & Reynolds
    • Mechanics
Replies
15
Views
2K
How Do You Calculate Static Pressure Drop in a Laminar Flow Channel?
    • Mechanical Engineering
Replies
3
Views
1K
Can Reynolds Number < 70 Cause Turbulence in Elbow Fittings?
    • Mechanical Engineering
Replies
20
Views
4K
Modelling Heat Transfer for Pulsating Laminar Duct Flow
    • Thermodynamics
Replies
20
Views
1K
I Laminar-turbulent transition and Reynolds number
    • Classical Physics
Replies
5
Views
1K
I Flow rate calculation for laser cutting nozzles
    • Other Physics Topics
Replies
3
Views
1K
COMSOL: Problem about optimization applied to a laminar flow
    • MATLAB, Maple, Mathematica, LaTeX
Replies
1
Views
3K

Hot Threads

Recent Insights

Back
Top