FLUID (Fast Light User Interface Designer) is a graphical editor and GUI builder that is used to produce FLTK source code. FLUID edits and saves its state in text .fl files, which can be edited in a text editor for finer control over display and behavior.After designing the application, FLUID compiles the .fl file into a .cxx file, which defines all the objects from the .fl file, and an .h file, which declares all the global ones. FLUID also supports localization of label strings using message files and the GNU gettext or POSIX catgets interfaces.
A simple program can be made by putting all non-interface code (including a main function) into the .fl file, thus making the .cxx file a single source file to compile. Most programs are more complex than this, so other .cxx files can be written that call the FLUID functions. These .cxx files must #include the .h file, or they can #include the .cxx file so it still appears to be a single source file.
Normally the FLUID file defines one or more functions or classes, which output C++ code. Each function defines one or more FLTK windows, and all the widgets that go inside those windows.
Widgets created by FLUID are "named", "complex named", or "unnamed". A named widget has a legal C++ variable identifier as its name (i.e. only alphanumeric and underscore), and is defined by a global variable or class member that will point at the widget after the function defining it is called. A complex named object has punctuation such as '.' or '->' or any other symbols in its name. In this case, FLUID assigns a pointer to the widget to the name, but does not attempt to declare it. This can be used to get the widgets into structures. An unnamed widget has a blank name and no pointer is stored.
Widgets may either call a named callback function that one writes in another source file, or one can supply a small piece of C++ source and FLUID will write a private callback function into the .cxx file.
Hello, everyone I am new to the site
I was wondering if the Universe and gravity are types of fluid?
As you can read I am not a cosmologist or even a physicist but I love science
Hi everyone, I have been hunting all over the Internet for an explanation to changes in the blood pressure when sitting, standing or lying down. I know the complex mechanisms that are involved but I need an equation for an ideal system with the heart in the middle and the pressure that needs to...
Homework Statement
Two identical balls A and B are dropped from rest into a tall column of viscous liquid. Ball A is dropped from the surface of the liquid while ball B is dropped from a small height ##h## above the liquid. Let ##E_A## and ##E_B## be the loss in mechanical energy of bal A and B...
Good day to all!
I have a question : We have a flowing fluid ( liquid ) with known pressure, flow in the pipe ( pump is pumping it). There are some spherical microparticles in the liquid, let's say 10-15 microns. I want to create force to stop them moving! Will the pressure force be in the form...
Homework Statement
Mercury is poured into a U-tube as shown in Figure a. The left arm of the tube has cross-sectional area A1 of 9.4 cm2, and the right arm has a cross-sectional area A2 of 4.50 cm2. One hundred grams of water are then poured into the right arm as shown in Figure b.
(b) Given...
Hi, I study linear momentum. But I cannot understand enough that how can forces appear on a pipe when fluid flows in the pipe? Fluid have a momentum as m*v how can forces appear on the pipe. I cannot demonstrate the situation in my mind. How can I find a demonstration or a free body diagram for...
As shown in the attached image, a tank has an inclined wall at an angle of 450 to the horizontal. On this wall, there is a 1m square door that is hinged at A and has a simple latch at B. The distance between A and the free surface of sea water measured along the inclined wall is 2 m. (Specific...
Homework Statement
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When asked for the bouancy of a hollow cylinder, containing air, submerged in ocean water.
outer radius R.
Length of cylinder = L
The Material of the cylinder is neglected.
I'm thinking the Bouancy (Force) = ρ ⋅ g ⋅ v
where v = LπR^2 and therefore F = ρgLπR^2
But the...
I am trying to determine which fluid to use in an experiment.
An important aspect of the experiment is the ratio of inertial forces (due to mass) vs the viscous forces that the fluid will experience
Amongst common liquids the lowest I can see is Acetone with a kinematic viscosity of 0.41 cSt...
Hi,
I'd like to know how I'd put together, either elegantly or at least in physical terms, that surely water evaporation in a large pool of V volume and S surface is influenced by wind (increased by it as opposed to having side barriers), temperature (increased by direct sunlight as opposed to...
I'm looking for a book to really help hit home what my fluids class is teaching because I'd like to eventually learn the Navier Stokes Equation.
Syllabus:
1. Introduction, definitions, fluid kinematics
2. Hydrostatics, including nanometers, Bourdon gauges and pressure transducers
3. Control...
water moves over a stationary horizontal flat plate of one-meter length. if velocity of water is 1 m/s, draw boundary layer and friction coefficient versus x for this plate.
hint: start your curves from x=1cm.Professor asked us to do it in Matlab or Excel and I'm not sure I understand how to...
In Bernoulli equation we use pressure energy... Pressure* volume gives the unit of energy... But what does this mean... If someone says it is potential energy per unit volume, then what does datum head refers to?... Please help... Can't go ahead without having thorough knowledge about this..
Hello everyone
I have a simple question regarding how to calculate the speed of a fluid in a normal pipe with a constant cross-section
If we are given the pressure difference at the two ends of the pipe (P1 and P2) is it possible to calculate the speed of the fluid? (I think I can imagine this...
Hello,
My memories of fluid mechanics are very rusty and therefore I was wondering if you could help me with this hypothetical problem. Let's say I want to generate very high hydrostatic pressures in a liquid (of order of 400 kbar). Would it be enough to do the following: take a rod weighting 1...
Fluid or sleeve bearings use an off center shaft location to generate a hydrodynamic wedge in direction of rotation. This converging fluid causes higher pressure and can support a load applied normal to shaft axis during rotation. This action appears to be similar to the hydrodynamic support of...
Hi all,
I am analysing the flow of water in a subsea pipe, and have been getting stuck in trying to solve the energy equation to plot a temperature distribution across the pipe diameter
I have derived the equation as such seen in my attachement. But my main question is how should/would I...
How can I calculate the pressure exerted by a fluid on the walls of the vessel that is being agitated. The vessel is not pressurised. I have to calculate the resultant pressure on the walls to calculate the thickness of the vessel walls.
hello,
in numerical fluid dynamics there are field methods like finite-volume, finite-element, etc. and particle methods like Smoothed-Particle-Hydrodynamics – SPH and others. Both approaches have advantages and disadvantages depending on the application. Both, in principal completely different...
I am intrigued by the diversity of Non-Newtonian fluids and need to ask a question.
Can anyone provide me with a breakdown of what goes on at the quantum level as the Non-Newtonian fluid bounces up and down on top of the speaker in the video I have embedded.
What I would like to know is...
Hi guys, please help me with these questions. I've been racking my brain for days but I'm not sure of the answers.
1) (Assume that pump similarity laws are valid and that the effects of Reynolds number (Re) are small.)
A centrifugal pump operating at speed N is combined in series with an...
Homework Statement
This is simply a sanity check concerning the system described and attached. My concerns are detailed within my attempts at the solution. Any guidance will be greatly appreciated!
The diagram attached represents a process for which a pump and associated pipe work require to...
Homework Statement
is it correct to say that the force exerted by reducer on fluid directed to the left because of the fluid move from left to right ?
Homework EquationsThe Attempt at a Solution
If you place an solid object on a fluid, is the force it applies to the fluid equal to the buoyant force? I would have thought that it applies a force equal to its own weight but that would mean that the force applied to the object by the fluid, the buoyant force, would not be equal and opposite...
Hi, all
I am working on a project that involves analyzing fluid flow behavior in oil & gas pipelines.
I am interested in calculating and plotting the velocity profile, and also(pressure distribution, temp distribution)
Having studies fluid mechanics last year I am aware of the EOS for fluid...
Hi there,
I have recently been experimenting with solid metal spheres being let to fall through fluids of different viscosities and have recently been introduced to the 'Ladenburg correction'. This correction multiplies the measured velocity of the sphere to obtain the 'correct' velocity used...
Homework Statement
http://imgur.com/DSBFIeO
I want to find the flowrate through this pipe based on the pipe's diameter, height of the pipe and the pressure difference. I tried to use Bernoulli, but since the diameter on either end is the same, the terms cancel out. I guess Bernoulli's equation...
How does one setup the stress tensor for a non-Newtonian fluid? I know that for any fluid the normals should be the pressure and for a power law fluid the shear stress in the direction of flow is related by K(du/dy)^n. Does this mean that all other components are 0 for a symmetric pipe or...
Homework Statement
why the formula of weight of fluid block is given by the formula of ρg[ (R^2) - pi(R^2) ] 1?
what does the 1m mean here ?
shouldn't it = ρg (pi) (R^2) h ?
2. Homework Equations The Attempt at a Solution
Homework Statement
why the fluid need the wall to eliminate the shear stress?
Homework EquationsThe Attempt at a Solution
is it because if there is no wall to support teh fluid , the fluid would move continously , resulting the shear stress act on water?
Homework Statement
Im working with a UROV and I have a technical scenario that I am supposed to solve. It seems pretty easy but i keep getting ridiculous answers.
Assuming a max thrust of 5 N for 1 motor/propeller, for the forward direction only, use the above information to determine the Max...
So there is this ball held on a spring. It's radius R = 0.015m , and density ρ=7800kg/m^3.
It's oscillation period in air is 1.256 seconds and in the fluid it changes to 1.57 seconds.
Find the viscosity of the fluid considering that the drag force obeys Stokes law.
I first found the spring...
Homework Statement
A 15 cm. radius cylindrical air duct is used to replenish the air of a room 10 m.*6 m.* 3m. Every 10 minutes. Determine the speed of the air through the duct in m/s. A1=15 V1=? A2=19 V2=0
Homework Equations
A1V1=A2V2
The Attempt at a Solution
3.14*15^2 * ?= 19*0=...
Homework Statement
Find acceleration for a general point (x, y) at time t, in the velocity field u = (y, t-x)
Homework Equations
Du/Dt = ∂u/∂t + (u⋅∇)u
The Attempt at a Solution
∂u/∂t = (0, 1)
(u⋅∇)u = [(y, t-x)⋅(∂/∂x, ∂/∂y)](y, t-x)
= (0 + 0)(y, t-x) = (0, 0)
Thus Du/Dt = ∂u/∂t +...
Homework Statement
. Air, at a flow rate of 30 [N/s], flows through the reducer shown below. In the 300 [mm] diameter section of the pipe the specific weight of the air is 9.8 [N/m3 ]. When flowing through the reducer the pressure and temperature will fall causing the air to expand and...
T1. Homework Statement
a wooden ball of mass m is kept inside water by the help of a massless string shown in the figure. One end of the string is fixed at the bottom of the vessel. when the vessel containing the water is accelerated upwards with acceleration a , will the tension increase and...
Homework Statement
A time-dependent two-dimensional fluid flow is given, in a Cartesian coordinates system (x, y), by the velocity field:
u = (y, t-x)
Show that, at time t = 0, the streamlines of this flow are circles centred on the origin.
Find equation of the streamline that passes through...
Hello there Physics Forum!
This is my first post here. This problem has been boggling me all day and I'm need of help in piecing together what I've come up with so far.
I'm currently working on a personal project related to paint spraying. In this project I'm using a syringe & needle to feed...
Homework Statement
A cart has a tank of water on it which has a nozzle. Water jets out from the nozzle onto a turn vane oriented at theta = 30° which deflects the flow upward. The cart is held stationary by a rope as shown in the image below. Find the force in the rope if the velocity of the...
Homework Statement
Water flows through a 1.5 [in] diameter pipe. In a 1.5 [ft] section of the pipe water is injected through the porous walls into the pipe at a velocity of 3 [in/s]. What is the average velocity at the exit if the inlet velocity is 6 [ft/s]?
Homework EquationsThe Attempt at a...
The question:
There is a 650m long tube on a 1 degree incline. At one end of the tube is a pump that alone has a volumetric flow rate of 750 g/min. The fluid in question is water and its a PVC pipe. What diameter does this tube need to be in order to have 25 psi on the top end of the tube...
Hi, I'm looking for a liquid that is nontoxic, high transmittance, has a specific gravity higher than 1.3.
Here is the catch. I'm using it to separate resin, so it can not dissolve or react with resin.
there was a similar topic on high density fluid on other forums, but I'm using it...
Hello,
I'm doing some online research on fluid flow in waste water treatment. One of the problem I'm trying to find information about is how can visible particulate matter be separated within a liquid. I saw the following picture:
What fluid concepts are going here that allow the grit to...
Homework Statement
A rectangular plate AB is 1.8 [m] wide and 2.0 [m] long. As shown below the plate is used to keep water (blue region) confined to the region. Find the weight of the gate necessary to keep the water enclosed. Assume the hinge at A is frictionless.
Homework EquationsThe...
I'm not really sure where to post this. I saw that this Homework section exists even for technically non-homework (I'm designing a machine at work, but the problem is homework-esque and my fluid dynamics knowledge is rusty at best). I'm not sure if this introductory or advanced, and the template...
1. Air at 0∘C flows through the tube shown in the figure. Assume that air is an ideal fluid. What is the air speed v1 at point 1?2. Formulas: A1V1=A2V2, ΔP + 1/2ρΔV2, ρgΔh3. My first through process was to calculate the change in pressure in the mercury as the change in pressure in the...
Homework Statement
what's the difference between zs and hc ? in the pictuire , they are both drawn from the bottom of water to the free surface ...
Homework EquationsThe Attempt at a Solution [/B]