# Questions tagged [vortex]

The tag has no usage guidance.

331 questions
Filter by
Sorted by
Tagged with
29 views

### How do I find the absolute maximum and minimum values of the Lamb-Oseen Vortex?

For an angular velocity function derived by Navier-Stokes, $$\omega \left(r,t\right)=\frac{\omega _0R_0^2}{R\left(t\right)^2}exp\left(-\frac{r^2}{R\left(t\right)^2}\right)$$ from which the azimuthal ...
27 views

### What is the relationship between a fluid vortex's expansion rate and its kinematic viscosity?

I've read through research papers with very specific radius formulas pertaining to 2D fluid vortexes, such as confined rotation with variations in pressure and density ($\rho(r,t)$ and $p(r,t)$), ...
1 vote
33 views

### Is this assumption about a vortex's angular velocity reasonable?

I am deriving a velocity flow function $\psi(r,t)$ that could be derived by (1) establishing the relation between two vortex area functions, $a(t)$ and $A(r)$, using the disk method of integration, ...
1 vote
13 views

### What is the vortex pattern when the flow is passing an axis-symmetric vortex flowmeter?

It is wellknown that in 2D case, the vortices will be formed at the back of the bluff body and detached periodically from either side of the body in a pattern called Kármán vortex street. But what ...
• 138
15 views

### When pouring water into a water body, how does that form one or more vortices in the water body?

When pouring water into a water body, sometimes it forms one or more vortices and sometimes it doesn't. I know it has something to do with the conservation of angular momentum but what are the exact ...
127 views

### Why do jet engine vortices go toward the ground?

This image was shown to us to illustrate how a tornado forms due to a low pressure region (also see Jet engine vortices). I find it odd that the tornado always ends up at the ground, where it is a ...
• 12.5k
36 views

### How to derive the ODE from the EOM of vortex?

In the Lagrangian mode we have the equation of motion \begin{align} \partial_\mu F^{\mu\nu}&=j^\nu. \\ D_{\mu }D^{\mu}\phi +\mu^{2}\phi-\lambda(\phi^{*}\phi)\phi &=0. \end{align} Since we ...
24 views

### How to calculate the latitude/longitude by the RPM in the basin? [duplicate]

By seeing how the water swirls and whirlpools when going down the drain in a washbasin is it possible to tell something about the longitude or latitude where the individual is?
• 1,389
1 vote
46 views

### Hot dust contribution to whirlwinds forming

My father observed an event with a whirlwind and had an aha moment on its forming. What he saw was a weak wind blowing over a sun heated patch of dust, and when the dust rose up, all of suddenly a ...
• 111
74 views

### Metric of a rotating Cosmic String

I searched on the internet superficially but I couldn't find it. Is there any reference that find the solution to Einstein's Field Equations for a rotating Cosmic String? Personally haven't got the ...
47 views

### Cosmic string in real space

I am considering $U(1)$ global cosmic string. In the case of wine-bottle potential with real field ($\phi$), it is known that there exists a static solution that corresponds to cosmic string (or ...
39 views

### What will happen if three equal tornadoes compressed together in one axis? [closed]

Imagine, 3 completely equal tornadoes with similar spin are compressing together by huge outer force in one axis and we can control the amount of outer force, what will happen as we gradually increase ...
• 21
34 views

### Best Shape for Creating a Liquid Vortex

I am trying to create a vortex in a closed tube, and I am wondering if there are any resources with research on what shape would be most effective for creating this vortex. Literally any shape, paddle,...
• 1
50 views

### How does a shear layer make vortices?

How does a shear layer make vortices? If you have 2 streams of air that are moving at different speeds or opposite directions right beside each other, how does that make a vortex? What causes the ...
• 275
80 views

### Can vortices be formed in a non-viscous fluid?

As I understand vortices form when a part of a fluid is moving with greater velocity, than its neighbour parts, so its neighbour parts that are moving slower ''want to slow down its faster neighbour ...
37 views

### What is the physical significance of the cross product of curl of a vector field $v$ with another vector field $w$?

I think if curl of a vector field v corresponds to an applied rotation, it's cross product with a velocity vector field w (say) should give something analogous to the resulting torque. Am I close?
56 views

### Physical significance of $\vec{w}$ $\times$ $($curl $\vec{v})$

I think if curl of a vector field $\vec{v}$ corresponds to an applied rotation, it's cross product with a velocity vector field $\vec{w}$ (say) should give something analogous to the resulting torque. ...
36 views

### Frequence vs speed of a moving object

Imagine swinging wood stick using hand (say it's a 1-meter long cylinder with 2 centimeter diameter, just for the sake of argument). When doing it fast (angular velocity = $\omega_1$), it will create ...
• 21
39 views

### Vorticity in quantum field theory

Can you refer some good papers to read on quantum field vortices, and a comparison with classical field vortices?
1 vote
22 views

### Would flux tubes be prevented from passing through a sufficiently thick superinsulating layer?

Suppose you have a type-2 superconducting cube with a thick superinsulating layer passing through the middle of the cube; visualized below with (grey superconducting mass, violet superinsulator in ...
• 2,979
1 vote
32 views

### Assuming vortex defect pinning is equal, and number of tubes are equal should longer flux tubes lead to stronger pinning?

Suppose you have two superconductors that resemble rectangular prisms with identical width and length. The first superconductor call it $A$ is shorter than $B$ visualized below: Now both $A$ and $B$ ...
• 2,979
61 views

### What would happen if I swirl a bottle of water in the space station?

Right now I am swinging a bottle of water in a tight circular motion to form a vortex, the vortex will last quite a while after I stopped swinging it. The vortex will took the shape of a funnel in 1g ...
• 13k
1 vote
63 views

### Has Biot–Savart law real physics in fluids?

In this video from 28:27-36:50 author talk how Bio Sawrt law dont have any physics in aerodynamics, he say it is just math concept and how vorticity cant induce velocity in fluid somewhere in the ...
• 613
85 views

### How would we explain a whirlpool shape without using centrifugal forces?

How would we explain a whirlpool shape formed in a bucket without using fictitious forces like centrifugal force? I am in high school and my teacher always gave me the explanation for shape of ...
• 39
27 views

### How does a fluid element have vorticity if the stress tensor is symmetric

Considering incompressible, Newtonian fluid as an example. The stress tensor is dependent on the symmetric part of the strain rate tensor, which is also symmetric. What I don't understand is, with a ...
1 vote
52 views

### How to calculate vortex movement in fluid dynamics?

I'm going mad...I just want to understand: Given there are three vortices of type "Rankine" in an incompressible 2D-fluid, each having radius R and a given vorticity $\Omega$ inside r<R. ...
• 1,299
45 views

### Coriolis effect in the bathroom? [duplicate]

I understand that the Coriolis effect is not responsible for the spin effect in the bathroom, but I have never seen a rigorous math prof of this. Where could I find a proof of this? What references ...
• 213
77 views

### What does vorticity and circulation physically signify?

When I see say a circulation value of 0, pi, 2pi or -12pi, what should this mean to me? I am a beginner in fm and have been trying to understand vorticity and circulation's physical significance and ...
• 27
93 views

### Can an ideal fluid undergoes a turbulent flow?

I have read before that the existence of viscosity is the main reason for the appearance of vortex. However, by definition, an ideal fluid has $\eta=0$. So, can an ideal fluid undergo a turbulent ...
• 959
66 views

### How can the vortex be an elemental potential flow if there is a point of curl?

Aero is not my speciality at all so apologies if missed anything. But when looking at potential flows, i thought the whole point is for there to be no rotation at any point and its that reason the ...
• 113
514 views

### What is the physical meaning of "flow" or "circulation" in fluid dynamics?

In fluid dynamics, the line integral of velocity field is called "flow," or "circulation" if the curve is closed. But does velocity times length correspond to any physically ...
• 644
57 views

• 113
181 views

### Do hurricanes spin?

It is often said that the spin of a hurricane forms as a result of being in a rotating reference frame with the spin caused by the coriolis force. For example, if you’re on a merry-go-round and you ...
148 views

### Material derivative of circulation, Kelvin's theorem

i'm trying to work with the material derivative $$\frac{D}{Dt}=\frac{\partial}{\partial t}+(\vec{u}\cdot \vec{\nabla})$$ of the circulation $\Gamma=\oint_{C=\partial S}\vec{u}\cdot d\vec{l}$, that ...