# Tag Info

5

I should start with the disclaimer that I don't know the answer to this, however I have seen very similar patterns in flocculating systems and I would guess that the same principles are involved. The patterns are produced by adding a drop of pigment to a layer of slip. Both of these are colloidal suspensions. Slip is a suspension of aluminosilicate ...

4

Option 3: Squeezing the bottle. Of course it depends how much pressure you are able to do, the strongest you are the fastest, and if you compress the bottle in an industrial press, the water will leave in a split second without breaking the bottle (well, it gets deformed, but that was an option).

3

For a candle flame, following processes occur. 1. heat transfer (from flame to surrounding and to candle) 2. material transfer (wax vapor diffused outwards and oxygen diffused inwards) 3. heat generation (chemical reaction at stoichiometric mixture location) with gravity, the above will shift due to free convection flow. This will accelerate heat transfer, ...

3

What I have observed is that if we turn the filled bottle (open) upside down and plug in a straw then the water starts to flow out faster. This happens because by plugging in a straw we make a way for air to come inside the bottle and fill empty space. Another observation that I've made is that when water is flowing out of a bottle (upside down) just shake ...

2

UPDATED ANSWER Sorry, I interpreted your question too narrowly. Couette flow occurs without a pressure gradient, due to viscous drag from a boundary surface, and is laminar. If the drag force is increased the flow can become turbulent. If a transient inertial flow begins laminar I think it must remain laminar as it dies out, because the speed of flow ...

2

A bit of 1, a bit of 3... The technical name is flow velocity, as correctly stated in the Wikipedia article about NS equations. But one could ask what "flow velocity" means. From the Wikipedia article: flow velocity [...] is a vector field which is used to mathematically describe the motion of a continuum. Although correct, this definition is ...

2

You are correct, it is the velocity of a small volume of fluid centered at the point, that is a macroscopic motion, but it is also the result of the average velocity of the particles in that volume.

2

Cut the bottle base and squeeze the bottle The air pressure has a major role to play in this situation. If you keep the bottle vertical, there wouldn't be any room for the air to move in as the water falls through which is the reason why you see turbulence and interruptions. There are various ways to tackle the issue. The best method would be to punch a ...

2

I doubt if the person who made that animated gif knew how the pump works. It's not at all clear why the valves open and close, and the regular movement of the water is nothing like an actual ram pump. It's more likely to confuse than enlighten people imo. This one (found on http://www.meribah-ram-pump.com) does a better job showing the strong waterhammer ...

2

The question is: what is the optimal way to pour the water so that it [the bottle] completely empties fastest? I conclude the aim is to have the empty bottle, not the water in another container. Solution: Create a centrifuge-like setup, bottle opening to the outside. The setup will generate artificial gravity for the water in non-inertial frame of reference ...

1

Using Bernoulli's equation and the momentum conservation equation, we can show that water flowing out of a pipe with cross-section $A$ at speed $v$ exerts a force $F$ on a wall (at 90 degrees), acc.: $$F=\rho Av^2$$ With $\rho$ the density of the water. But your specification of "8" pipe with 500psi stream of water exiting it and hitting a wall at 90 ...

1

You need to get $p_4-p_3$. Taking the datum of elevation z as that of points 3 and 4, we have $$p_{atm}+(10)\rho g=p_2+\frac{1}{2}\rho v^2$$ $$p_3+\frac{1}{2}\rho v^2=p_2+\frac{1}{2}\rho v^2$$ $$p_{atm}+(120)\rho g=p_5+\frac{1}{2}\rho v^2+(120-h)\rho g$$where h is the depth of point 5 below the surface of the tank on the right. p_4+\frac{1}{2}\rho v^2=...

1

what i do not understand is why does the waste valve open (and close) The waste valve is normally open. In your figures, the plug is weighted and falls away from the valve. The water flow through the waste creates drag which pulls the valve closed. and how does it sync with the check valve? When the waste valve closes, it causes the pressure in ...

1

This is a correct way to solve exercises involving viscosity (within certain constraints, e.g., constant viscosity). Eqn. 1 is a version of the Bernoulli equation, modified to include a frictional head loss, and is definitely valid, provided the velocities used are the average velocities. Eqn. 1 without the $h_L$ is valid along a streamline, even for a ...

1

I am telling this from my practical experience. In my home we have very poor water supply so we purchase 15 ltr water dispenser for drinking water. The guy needs to take the bottle back. So he shake the bottle such that water make a kind of whirlpool while still keeping it straight and then quickly turn it upside down at an angle. The water flows quickly out ...

1

The convection-advection equation resembles the mathematical structure of Burgers equation. Despite differences (convection-advection has an "extra" variable $c(x,t)$) you can think that Burgers describes compressible material fluid transportation by means of advection (the $\vec{v} \cdot \nabla$ term) and diffusion (the $D \nabla^2$ term) without ...

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