Questions tagged [bubble]

A coherent region of fluid embedded in a fluid with different properties (air in water) or a coherent region of fluid surrounded by a membrane embedded in a fluid which may or may not be different (such as air in a soap membrane).

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How is energy stored in the surface of a bubble?

In the book of Prigogine, Modern Thermodynamics, it is given on page 147 that Another example is the natural evolution of the shape of a bubble enclosed in a box of fixed $V$ and $T$. In the ...
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Bubbles in pressure waves

I found an article in which they say this, at the end they say that there is a net flux of gas into the bubble, but I don't understand why, since there is a dilatational phase (in which the bubbles ...
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Formation of bubbles in a fluid

I'm reading an article (The fluid mechanics of bubbly drinks by Roberto Zenit), I have a question about it (the part of which is added as a picture) In the article they say that the gas cavity will ...
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Effective viscosity in bubbly liquid

Motivation: I have screwed some crepes big time this morning and it made me think... Consider a bubbly liquid (such as a crepes batter if you whisk it too much). Is there an approximate measure of ...
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What kind of propulsion would a Scrubbing Bubble use [closed]

The brand name bathroom cleaner Scrubbing Bubbles has a mascot, that is a bubble with a rotating bush on the bottom. Please view this video to see an example of the motion. I would like to know what ...
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Help with obtaining the derivation of the resonance frequency of a bubble [closed]

I have a question with regards to the derivation of the resonance frequency of a bubble described using the bubble dynamics equation in the paper I'm currently reading (Eqn 1): $$\frac{3}{2}R_t^2+RR_{...
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What causes this phenomenon when boiling water?

A few days ago, when boiling potatoes I only cut each of them in half (leaving a flat face in each half). When the water started bubbling a little (and also later when it was boiling) the flat face of ...
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A question about Laplace law

In Laplace law, the force on a soap bubble from inside is $F = P.πr^2$ and what I understand that the leaning forces acting on the inside of the sphere are resolved into two components the vertical ...
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Questions about Vapor Pressure and Cavitation Bubble

I am currently learning about cavitation in my fluid mechanics study. I am confused about the definition of Vapor Pressure, does it exist only in the saturation line? I am also confused about how can ...
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Why do gas bubbles stick to the surface of the bottle?

When a bottle is left out in summer for sometime gas bubbles are formed on its walls and they remain there unless they are disturbed. But why does it happen so? I mean the water is exerting buoyant ...
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Observed that under-water bubbles are very resilient: what causes this?

Noticed that bubbles could simply not be burst while underwater -- a bubble that was underwater with part of the surface touching the wall of the tub if pressed upon with a finger would simply move -- ...
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Why does foam in a rotating liquid accumulate near the centre?

I first noticed this while having a coffee. When the coffee was rotating in the cup, most of its foam accumulated near the centre. I recreated the effect with some soap and water. The accumulated foam ...
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103 views

What happens during cavitation?

Cavitation is vapor bubbles and when they implode creates a shock wave, before imploding the bubble can reach temperatures of 10000k. I want to know what conditions must be met to make cavitation, ...
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Time taken by bubble to come to surface

Does air bubble take same time to emerge from shallow water and deep water? I think the acceleration due to buoyancy will be the cause.
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Why Air bubble are always sphere in shape? [duplicate]

Everyone of us had noticed air bubbles once in his life. They are Sphere in shape. But I want to know why the are sphere in shape, instead of any other shape.
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67 views

Movement of bubbles in a cup of tea

Why is it that when I try to scoop bubbles out from the surface of a cup of tea, they always slip off the spoon even if some of the tea does not?
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What kind of forces develop on a solid shape suspended in bubbly fluid? Is there a name for the study of this sort of interaction?

Let's say I have a solid shape - a sphere, a cylinder, I don't know if it matters - and I place that solid in a container of water. The forces on the shape consist of gravity and buoyancy (due to ...
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Does a thickness of a bubble become constant over time?

Assuming no gravity, imagine you have a bubble floating in the air, does its thickness have a tendency to become constant? State a bit differently, if we start with a bubble with variable thickness, ...
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Bubble optics, impact

My 8 years old daughter was blowing soap bubbles. Most of the bubbles had color. She randomly choses a bubble with colors and lands it on the wand. Instantly it's color is gone. If she blows this ...
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Bubbles in a Pipeline 2

This question has kind of been asked before here, but aren't the gas bubbles in the pipeline also a moving fluid and so as they get constricted shouldn't their pressure decrease too. If so how are ...
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Bubble flow in vertical pipe

I have an application where I would like to keep a bubble flowing freely within a pipe. Assume a single small, spherical, non-deforming gas bubble in a viscous, laminar fluid flowing in a vertical ...
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139 views

Optics of thick soap bubbles

There was some discussion in a previous thread ( Why are thin soap bubbles colorless? ) that talked about thin soap bubbles. My question is, what if we go the opposite way? Why are thick bubbles ...
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137 views

Why do soap bubbles seem to resist merging?

When playing with soap bubbles in a bathtub, it seems impossible to bring two bubbles together to form a single larger bubble. When two floating bubbles meet, a wall is formed between them. Even when ...
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Why are there less bubbles the second time I pour soda in the cup?

I poured some Pepsi into a mug, and it foamed, and I poured until the foam was at the top of the glass. I waited a few seconds for the bubbles to go, and the liquid level was revealed to be at around ...
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Why does soap solution forms bubble but tap water does not? [duplicate]

The surface tension of water reduces on addition of soap to it. Then why does normal water not form bubbles but soap does even with less surface tension?
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Why does air get trapped below water pouring into a glass?

The drinking-water-tap at my workplace has a low pressure continuous stream of water. When I pour water into a glass which has at least about (depth) 5cm of water in it, surprisingly large air bubbles ...
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What is the equation of state of foam, on a macroscopic scale?

Consider a large amount of soap foam (or any other substance producing foam), of mass density $\rho$ in a gravityless environment. What is the internal pressure $p$ of that foam, viewed as a fluid on ...
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Water vapor pressure in oxygen bubble

Suppose we have a source of O$_2$ bubble formation in water at specific nucleation sites, how can we estimate the water vapor pressure inside the O$_2$ bubbles? I know that: (1): $p_\mathrm{O_2}+p_\...
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Surface tension and entropy

I think of surface tension as work/area, just as pressure is work/volume. I understand it to measure energy rather than free energy. I should think that a molecule on the surface of a liquid would ...
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Why are we able to see air bubbles under water?

Title is self explanatory. I'm assuming both water and air are transparent. So, if they are true, how can I clearly distinguish an air bubble under water?
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Why do bubbles initially stick to the side or the bottom of a glass while boiling?

When boiling water, I've noticed that bubbles will appear to grow at the bottom of the glass for a period of time and then rise. I've read that bubbles form from nucleation centers but I don't know ...
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How long does it take for oil to coalesce in water?

I was studying the process of coalescence in emulsions. We considered $N$ bubbles of liquid 1 floating in liquid 2. The result we derived, is that if there are some dissipative forces (diffusion) the ...
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What keeps small mobile bubbles at the bottom of a kettle from rising

We have a glass jug water kettle with a flat heat plate as the bottom. It boils water quite vigorously in 2-6 minutes depending on how full with a 1000+W element. Just today I noticed that very ...
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758 views

Pressure inside a bubble

Consider a bubble with radius $r$, inner pressure $P_v$, and outer pressure $P_{\infty}$. When we choose our control volume (blue dotted line in figure) to encompass half the bubble, we have a surface ...
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Why are the “bubbles” at the edges of my soup so large?

At lunch today, I was eating chicken noodle soup. After finishing most of it, I turned my attention to a sandwich and let the soup sit for about five to ten minutes. When I looked back, I noticed that ...
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Champagne bubbles and gravity

One of the influences on bubble size is the speed with which a bubble rises in a glass - this, I believe, is due to the force of gravity which acts on the liquid around the CO2. The greater the ...
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Why do bubble rings stop rising near the surface, and then spontaneously dissipate?

When I've blown bubble rings in my pool I've noticed that every single time a ring rises to the surface it stops rising about 1-2 centimeters from the surface, stopping in place. Then, it ...
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63 views

Best way to pour a too-carbonated beer?

I hope people have fun with this. But, for those who aren't interested in fun, here's a Tl/Dr: What is the fastest way to disperse foam from an overcabonated drink being poured. For example, is it ...
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Bubble with varying pressure over surface

I was wondering if it's possible to have a soap bubble with a varying pressure over its surface? That is, such a bubble would not have constant internal pressure at all points. I am specifically ...
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Why does not a bubble in a thick hand sanitiser not rise?

Here is a picture of a bubble trapped inside a thick hand sanitiser. These bubbles never rise despite not sticking to the walls! They just remain stationary, in the middle of the liquid, despite the ...
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Is the trajectory of a bubble a good indicator of the direction and velocity of air flow?

I'm wondering if a soap bubble is a good "measurement device" for the flow field of air it is surrounded by. If I could somehow create many bubbles in an array, could I infer the flow field of the air ...
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Is it possible to create a soap bubble in space?

since space does not contain air, is it possible to create a soap bubble without air in space or in vacuum and can can you explain why so? OR will there be any possibilities for a bubble in such kind ...
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Will a soap bubble remain stable if its surface is uniformly charged?

Considering a uniformly charged spherical shell, it is easy to show with a virtual work argument that the pressure will be given by $$ p = \frac{Q^2}{32\pi^2 \epsilon_0 R^4} $$ On the other side, ...
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Can bubbles lower water pressure?

After watching a TV show I saw that bubbles originating from underwater can lower the impact damage when something hit it at velocity. I was wondering if another implementation of this would work. ...
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What is causing the repeated creation and destruction of bubbles in boiling starchy water?

A while ago I was cooking rice, and I noticed a recurring pattern of creation and destruction of bubbles. It seemed like the bubble-layer would increase in height, until it 'popped', and the layer ...
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What determines the lifetime of a soap bubble?

I'm wondering why soap bubbles only last some seconds in average. There is almost no wind in the closed environment I create the bubbles in. Regardless of whether they adhere to a surface (e.g. the ...
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In a real life system of waving a bubble wand or baton around how do you determine when chaos has occurred?

In a real life system of waving a bubble wand or baton around how do you determine when chaos has occurred?
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Why do turkey bacon slices form bubbles in the same places?

Often, turkey bacon forms large bubbles when cooking. It's simply a fact of how it cooks. More interestingly however, I was making turkey bacon this morning when I noticed that all of the slices ...
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Is the energy of sonoluminescence derived solely from ultrasound?

Sonoluminescence occurs when a small gas bubble is oscillated in a liquid solution with ultrasonic frequencies. The bubble's collapse and cavitation results in light emission and thermal energies that ...
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What can be the simplest way to find the thickness of a soap bubble?

Is it possible to measure the thickness of a soap bubble without using any sophisticated instruments such that anyone can do it?