Capillary Definition and 113 Threads

Hello, I designed a tiny peristaltic pump which works really fine. I am using a very thin tubing of 0.5mm diameter, which makes me struggle with capillary action, unfortunately. When my pump is not working, sometimes liquid still flows into the tubing because of capillary action. Do you have...

Is there a way to measure the critical capillary number? I am running water flooding tests in micro single capillary ducts. I am displacing oil in my experiment, and my channel should be oil wet. I was able to measure the properties of both fluids, this includes; Kin and Dyn Viscosities...

I'm having some trouble getting my head around the scale at which capillary flow and contact line dynamics are important. In the simple case of liquid rise in a capillary tube, a smaller tube will allow for greater rise since a larger height is required to achieve an equal weight of the liquid...

I am learning about capillary action of water. As water moves up paper. How is that not violating energy conservation as it is going against the force of gravity. This obviously can't be infinite energy.

When figuring out the capillary pressure on a liquid in a tube of a certain cross-section, the typical approach is to consider the Young-Laplace pressure and the curvature etc. I was looking through some of my old notes and I had an equation for the capillary force: fc = γ cosθ dS/dx where γ...

I was researching capillary action to design an efficient evaporative cooler, when I found this thread... https://www.physicsforums.com/threads/using-capillary-action-to-raise-water-is-perpetual-flow-possible.551285/ Upon reading this thread, the statement, "Trees are solar driven evaporative...

According to this definition I am unable to understand why does surface tension acts tangentially to surface of contact of liquid and capillary tube. And is the force of surface tension balancing the adhesive forces which lead to capillary rise OR it is the reason behind the capillary rise?

Please, I need a good books about the meaning of "Gravitational and Capillary waves "

I know that the height in general is goven by 2σcos(θ)/(ρgr). So the maximum height can be 2σ/(ρgr) with cos(θ)=1. But the answer given is c.

Homework Statement Hello everyone, I am doing an experiment and I've hit a snag with my calculations. I am looking at how concentrations of soap affect surface tension in water. I am have been using the capillary equation and capillary tubes for my calculations. I have practiced this method for...

Homework Statement A 20 cm long capillary tube is dipled in water.The water rises up to 8cm .if the entire arrangement is put in a freely falling elevator ,the length of the water column is A)10cm B)8cm C)20cm D)4cm Homework Equations Its a theoretical sum The Attempt at a Solution...

It's a question which come into my mind after reading related notes now and again and I can't think of plausible response to it. Given Statements: We have a container filled with mercury and a glass capillary tube placed in it . As tube's diameter become smaller mercury's height in tube will get...

Hi everyone I am trying to build an experiment with microfluidics. I have a reservoir containing a bellow. This bellow is a compensation mechanism and makes sure that the liquid (in this case water) can be pushed out of the reservoir. Before storing the fluid in the reservoir, the reservoir is...

I've been trying to understand how dilution refrigerators work and inbetween intermediate steps, between different temperature points, I see capillaries here and there under the name of impedances. After some googling, I somewhat convinced myself that it's to build up pressure before and after...

Hi PF! The capillary number is defined as ##Ca = \mu V/\sigma##. Does more inertia in a fluid increase the capillary number? As inertia increases, it's my intuition that so does velocity. Then it seems (all else constant) that ##Ca## increases too. Is this correct?

Is the adhesive force greater in a smaller tube then a bigger tube at the top? So would it take more energy to take out water at the top of the straw from the thinner straw? Or would, due to gravity cancelling eventually the capillary rising, the adhesive force at the very top of the straw is...

I calculated the energy density of capillary waves with Debye method (pretty much Debye model in 2D), and I assumed there is a frequency cutoff for capillary waves as well. However, when I checked my work with solution I was quite surprised that the solution suggests there is no such a cuttoff...

Hi PF! I'm trying to model a fluid dynamics problem where there is flow in a wedge. Length scale is 160mm and two fluid phase: air sits on top of silicone oil. Boundary conditions can be to specify height conditions, flow rate, et cetera. Very low gravity, so surface tension is very relevant...

Capillary action is a form of work, i.e. an object (water) moved by a force (capillary action) over a distance. Since all work requires energy, what supplies the energy for capillary action? Is the chemical energy of the water increased by adhering to a surface? Perhaps the heat energy of the...

How does the capillary tube decrease the pressure on the liquid when its diameter is smaller? How small diameter of capillary tube is helpful in causing more pressure drop? And how, when pressure drops, the liquid instantly cools down?

Homework Statement Why there's no pore pressure due to capillary rise at point A and point D ? There's only pore pressure due to capillary rise at B .. Homework EquationsThe Attempt at a Solution i think the author is wrong . There's should be also ore pressure due to capillary rise at A and D...

Dear all, I have a problem to solve but i am not very familiar with physics. See attached image. Data: 1)I have a capillary system with a short an thinner tube on one end and larger taller tube communicating. 2) at the equilibrium, the thinner capillary is full of liquid, while there is a...

Hello, I am doing a project which includes attempting to map a theoretical pressure distribution across a capillary tube. I am trying to do a finite element analysis using Hagen-Poiseuille's Law to map the theoretical pressure distribution before I move onto using a SolidWorks Flow Simulation...

While going through the derivation to find the surface tension of liquid i came with the formula which says that the surface tension is directly proportional to radius of the capillary so does that imply if we use a capillary with a greater radius so the same will give the different value of...

When we put an empty capillary tube in a water container, the water goes up a little bit by itself until the surface tension (ST) force is equal to its weight .This shows that unlike friction, this ST force acts individually . So if we take out the tube out of the container, and drain a little...

I'm trying to understand capillary flow in a tube. I've found this http://folk.uio.no/eaker/thesis/node11.html that explains some aspects of it, the system is illustrated here, So the (black) non-wetting fluid resides to the left and the (white) wetting fluid is to the right. Say that we are...

Which materials have high capillary length, and can be found easily? (above 1cm)

Homework Statement The temperature across the capillary with constant cross-sectional area and length L is given by ##T=T_0e^{-kx}##. Assuming an ideal gas and constant pressure show the number of moles to be: $$n=\frac{PV(e^{kL} - 1)}{RkLT_0}$$ Homework Equations ##PV=nRT## The Attempt at a...

It seems that both the capillary number and the Laplace number represents the relative effect of viscous forces and surface tension. Can anybody explain the difference between them? Thanks a lot. I have attach the Wikipedia- links to these two concepts...

Homework Statement Consider an experiment on the International Space Station, which is illustrated below. A cylindrical capillary of length L= 10. [cm] and inner diameter of dc=500. [µm] (sealed at one end), is positioned to contact a droplet of water, D = 1.0 [cm], which is floating in the ISS...

I've been reading up on capillary action in a tube, and I have some questions: Say we insert a tube in a pool of fluid; Jurin's Law expression is ##h=\frac{2\sigma \cos \phi}{r\rho g}##. However, this height is not the height of the fluid measured from the bottom of the tube, but rather the...

Hello So like anyone who read about capillary action, you think about free energy generation, but as I read the problem is that the water won't leave the capillary tube on the other side because of the capillary action. So you need to use the capillary force from one end of the tube then...

In a demonstration of the qualities of liquid Helium in type 1, and type 2 the fact that a super-fluid can permeate through capillaries which are too small for type 1 Helium to pass through. I was wondering about the equation which determines the capillary radius threshold under which the...

When there is Capillary rise in tube of insufficient length, why does not the liquid overflow?

Hi, I was looking for a formula to describe capillary action speed in a medium. On wikipedia (https://en.wikipedia.org/wiki/Capillary_action) I came across a formula which describes the cumulative volume of a liquid drawn by capillary action after time t where V is cumulative volume, A is...

Hi guys, I'm doing a project at the moment revolving around capillary action and surface tension. Today I conducted an experiment to observe capillary action in a capillary tube and paper towel at different temperatures of water. I don't understand why I've got the following results: As you...

You have a capillary with a stream of water vapor flowing through. Inside the capillary argon gas is also flowing (in the same direction) with a flow rate of 3 L/min. How high of a flow rate can the water vapor have before it starts condensing on the walls? Flow is laminar and the system is at...

case 1)The hole is drilled before the liquid rises case 2) the hole is drilled after the liquid rises

Homework Statement Homework Equations height of liquid above water level ##h=\frac{2T}{R\rho g}## for isothermal process :##PV##=constant And if ##P_0## is atm. pressure, and P is pressure just below the water level in capillary tube, then $$P=P_0-\frac{2T}{R}$$ The Attempt at a Solution...

Hello, I'm an art student trying to recreate this phenomenon, but maybe on a larger scale. I'm trying to create a sculpture that is able to do that. If I can rely on just structure and not worry about materials, that would be great, since my plan is to be able to 3D print it out of plastic...

Homework Statement Kindly view the attached. Homework Equations ΔP = γ(1/R1 + 1/R2) The Attempt at a Solution [/B] I've began the topic of fluid mechanics, capillary pressure, surface tension and such and was given this question to try. Now from my limited knowledge it seems to me that in...

Hello Forum, I have some conceptual doubts about shear viscosity and would like some help if possible. In general, viscosity depends both on temperature and on shear forces (more strongly on shear forces). "Shear viscosity" is the viscosity that a molten plastic assumes when the molten fluid...

I have a strange problem. We test our components in oil in a hot chamber(60-100C). Wires are bought out of the chamber for power supply and data acquisition. The oil from the chamber leaks on to the wires because of heat and capillary action. This makes the wires oily and working with oily wire...

What happen when the capillary rise occur in a tube of insufficient length? My teacher told me that hR = constant where h is height and R is radius of sphere of which the curved surface of meniscus firm a part. She also told me that if h become less so R has to increase so radius of meniscus...

When we write the equation for expressing the dynamics of capillary filling, why don't we include the effects of pressure difference?

Hi everyone, I'm doing a simulation and need some help. A capillary which is closed on both ends with the length l (x=0 to x=l), with a radius R and the volume pi*R^2*l is dropped on a parachut at the time t=0 from a hight h above ground. At t=0 the pressure inside the capillary is p_i0 (this...

What's the difference between surface tension and capillary force? Surface tension, a tensor, is the force per unit length. Again surface energy is the energy required to increase the surface area by one unit. Is the surface tension a capillary force?

Homework Statement When the rate of blood flow in the aorta is 5 litres per minute, the speed in the capillaries is about 0.33 mm per second. If the average diameter of a capillary is 8 microns (0.008 mm), calculate the number of capillaries in the circulatory system. Homework Equations Flow...

Homework Statement Two tanks are connected via a capillary pipe, with one tank over the other. The speed in which the liquid flows from the upper tank to the lower tank is 3472 cm/min. The height of the liquid inside the upper tank is 30cm from the bottom of the tank. The capillary pipe sticks...

Good day I am interested in making a wicking bed for typical vegetable growing. I have read that the height of the soil should be no higher than 300mm. I suspect this number is experimental or simply copied from other sources. I am a little more curious regarding the mechanics of such a...