Mass flux across a volume - Physics Stack Exchange
Mar 28, 2015 · That is: The number of cubic meters entering the volume next to the cross-section every second times the mass of each cubic meter equals the total mass entering every second: m˙ = ρV˙ = ρAu m ˙ = ρ V ˙ = ρ A u. This m˙ m ˙ is what is called mass flow rate or mass flux. Addition: That your variables are symbolized as ρ(x, t) ρ (x, t ...
How can mass flux be defined for a one-dimensional flow?
Jan 14, 2019 · where the quantity m˙′′ A m ˙ A ″ is explained as the mass flow of substance A per unit area and its units are kg sm2 k g s m 2. YA Y A is mass fraction of substance A, ρ ρ is density and DAB D A B is binary diffusivity. In words, the above equation states: mass flux of A = bulk transport of A + diffusion of A.
Derivation for kinetic energy flux - Physics Stack Exchange
Feb 14, 2017 · Our flux therefore is ϕk =Ek = 12 m (v22 −v21) ϕ k = E k = 1 2 m (v 2 2 − v 1 2). We can set the initial velocity to zero and consider the Ek E k in each snapshot at that instant. Thus. Ek = 1 2 mv2 E k = 1 2 m v 2. This is valid for a single particle.
classical mechanics - On the definition(s) of flux/current density ...
Dec 21, 2022 · Electric current. In electromagnetism, we can define the electric current through a surface as the flux of electric charges across the surface. The volume density of electric current, the current density j(r) j (r), is defined as the product of the charge density times the local average velocity of the charges j(r) = ρ(r)v(r) j (r) = ρ (r) v ...
Is the Mass flow rate (Mass flux) a scalar quantity?
Mar 28, 2015 · 1. Wikipedia states that mass flow rate is a scalar quantity, however. Mass Flow Rate= Density x Cross Sectional Area x Velocity. and velocity is a vector quantity, so this would imply Mass Flow Rate is a vector? What is wrong here? The units alone can not tell you about the scalar or vector nature of something.
When the mass flux is constant, why does - Physics Stack Exchange
Apr 18, 2022 · Mass flux in a multicomponent mixture with a concentration-dependent density. 1. Given *an* expression for ...
Definition of Buoyancy Flux - Physics Stack Exchange
2. I've seen in some papers the definition of buoyancy flux as follows. B = gρa −ρ0 ρ0 Q B = g ρ a − ρ 0 ρ 0 Q. where g g is the gravity acceleration, ρa ρ a is the density of the ambient fluid, ρ0 ρ 0 is the density of the lighter fluid released into the ambient fluid from a point source, Q is the volumetric flow rate of the ...
Constant mass flux in fluid dynamics? - Physics Stack Exchange
Assuming the density and the velocity are constants over that area (at a fixed x x), the integral becomes: ρ1A1v1 =ρ2A2v2 ρ 1 A 1 v 1 = ρ 2 A 2 v 2. Possible second derivation Possible second derivation. There should also be another way of deriving this: Starting once again from. dm dt …
How does Galilean invariance lead to equality of "mass" flux and ...
Mar 18, 2020 · The footnote says "It must be borne in mind that, whatever the definitions used, the mass flux density j must always be the momentum of a unit volume of fluid ". This is exactly what is assumed for Galilean field theories. Landau seems to take it as a definition.
Intuitive understanding of the elements in the stress-energy tensor
May 14, 2015 · There is an image in the Wikipedia about the stress-energy tensor:. I have a rough understanding of the stress tensor: you imagine cutting out a tiny cube from the fluid and form a matrix out of the forces on each side of it: it's not hard to see that the forces that push the faces outwards so the x direction of the force on the x side, the y direction of the force on the y side, …