Tagged Questions
3
votes
1answer
144 views
Rayleigh-Benard Convection
I found this nice paper about RB convection. However I am confused by what is going on page 6. In particular why we are suddenly using Helmholtz equation to find spatially periodic solutions. Aren't ...
1
vote
1answer
1k views
Boussinesq approximation for the Navier Stokes' equation - discrepancy
In the Navier Stokes' equation:
$\rho_0 \left( \frac{\partial v}{\partial t} + v \cdot \nabla v\right)
= -\nabla p + \mu \nabla^2 v + \hat{f}$
I included the temperature variation of density as ...
8
votes
3answers
240 views
What is the microscopic picture for warm air rising?
The usual explanation for warm fluids rising past cooler ones is that the warmer fluid has a lower density. I'm trying to understand what this looks like at a molecular scale. The density seems to ...
4
votes
1answer
3k views
What exactly is the difference between advection and convection?
After reading Wikipedia articles on advection and convection, I still cannot determine whether there is a consensus on a difference between these two terms.
Sometimes, the term convection seems to ...
3
votes
1answer
70 views
Bifurcation of convection of fluid in container, when adding temperature
I once read a paper, in which:
a fluid in a container was heated from below,
after reaching temperature $T_1$, a circular motion (convection) was clearly distinguishable, in form of cylinder,
after ...
4
votes
2answers
2k views
Convective and Diffusive terms in Navier Stokes Equations
My question has 2 parts:
I just followed the derivation of Navier Stokes (for Control Volume CFD analysis) and was able to understand most parts. However, the book I use (by Versteeg) does not ...
1
vote
1answer
453 views
How does smoke move in the air and how can I direct it so it will go to a place I want it to go?
Let's assume a close room with 1-2 people who only one of them smoking cigarette.
What is the equation describe the smoking spreading? is it diffusion? what are the parameters is so?
Is there a ...
3
votes
2answers
164 views
Air velocity in a double-skin facade
I was wondering how the air flows in a double skin facade? Say I have a glass facade with a depth of 1m, a height of 200m and a width of 10m. It is a single vertical shaft all the way up with openings ...
