What exactly is the difference between advection and convection?
The terms advection and convection have different meanings depending on in which context they are used. Fluid dynamics. In fluid dynamics, advection is a type of convection, with the other type of convection being diffusion. Both advection and diffusion act to move around various intensive properties of a fluid.
What is the exact difference between diffusion, convection and …
Let me try to give you a visual picture of these terms in the advection -diffusion equation(ADE): Coffee cream mixing Advection (1st term in ADE): It is the mechanical motion of the fluid. For example, stirring a coffee cream by spoon. Diffusion(2nd term in ADE): After this mechanical/spoon action, cream will stretch and fold and form thin ...
Diffusion vs Advection - Physics Stack Exchange
Apr 1, 2018 · Advection is the part of convection due to a net force acting on all the particles of one substance, causing them to drift as if they're a point mass. (By "particles" of a "substance" I could also mean quasiparticles, such as phonons of heat, which convect in a mathematically similar way; a container with only one fluid material in it will ...
Convection vs diffusion - Physics Stack Exchange
Oct 19, 2016 · Convection is a combination of advection and diffusion, where the former is a macroscopic movement of bulk fluid and the latter is a microscopic movement of fluid particles. But often in literature, I see sentences like "The second and third terms of the left-hand side are the energy convected (advection) and the energy transferred (diffusion ...
Advection-diffusion with periodic boundary conditions and tilt
Jul 19, 2020 · Question: Any idea or reference about the diffusion-advection equation in periodic boundary conditions (in particular about the steady-state)? Which is the "Gibbs-like solution" in this case? Which is the "Gibbs-like solution" in this case?
homework and exercises - Advection operator - Physics Stack …
Jan 20, 2015 · The problem is in the way you wrote your last equation as a matrix multiplication. You have $$ [ \textbf u \cdot ( \nabla \textbf u) ]_i = u_j (\partial_i u_j) = (\partial_i u_j) u_j, $$ so if you want to write this in matrix form you have to multiply the vector $\textbf u$ at the right, as a column vector, i.e.
fluid dynamics - How can I see this equation describes advection ...
$\begingroup$ Well you don't adjust the advection equation, you derive a new one. In the case of the magnetic field, the temporal evolution of the $\mathbf B$ field depends on the electric field, you then can use the Lorentz force law (assuming no forces) to get that $\mathbf E=\mathbf v\times\mathbf B$, thus $\partial_t\mathbf B=\nabla\times ...
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 der...
Why is the momentum advection dependent on all 3 dimensions?
Apr 13, 2021 · For a 3D flow, the advection term in the x-momentum equation is $-\\nabla \\cdot (\\rho u \\vec{u})$. How does momentum flow in the y and z directions contribute to the momentum flux in the x direction?
9-point stencil “equivalent” for advection equation
Jul 24, 2015 · The 9 point stencil adds spatially "diagonal" components to the discretization. However, the advection part still has some pretty bad grid orientation problems. I was wondering if there is a "9-point stencil" analog to the 2D advection problem. Maybe a stencil that takes into account the "diagonal" cross-term spatial components somehow.