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.
Homework Statement
The Attempt at a Solution
So first I found the density of the air coming in and going out. Next I used conservation of momentum with two forces caused by the pressures at the entrance and the exit of the nozzle.
I end up getting 1004 which is not the same as...
Compute the coefficient of expansion α in terms of P and V...
Homework Statement
Compute the coefficient of expansion α in terms of P and V for an ideal Van der Waals
gas
Homework Equations
(p+a/v^2)(v-b)=RT
The Attempt at a Solution
Is this as simple as solving for a? How...
Hi all,
I have a question about calculating the concentration of continuous air and carbon monoxide flowing through a pipe. If the gas cylinder originally has 20% CO and 80% air and it will be diluted by another gas cylinder of air, how do you account for temperature, pressure, and...
Homework Statement
Here is the question along with my attempt:
As you see in my second equation there are two unknowns, A_out and dm/dt.
I think my problem is that I don't exactly understand the equation. dm/dt is the net mass flow rate. For example if dm/dt is a positive number then there...
when you stir fluid in a beaker of fluid, how is the motion on the fluid by the stirring rod calculated?
the fluid is represented using smoothed particle hydrodynamics lagrangian method so that I can look at fluid as a bunch of spheres interacting with each other through a sort of force...
Homework Statement
Use the continuity and momentum conservation equations for a single species to construct the following "convective derivative" equation for the fluid velocity:
\frac{\partial\vec{v}}{\partial t}+\vec{v}\cdot\nabla\vec{v}=\vec{g}-\frac{1}{\rho}\nabla p...
Does a pipe have to be completely filled with a fluid to measure its pressure? For instance if I have a small diameter pipe that diverges to a bigger pipe. The small pipe will be completely filled with water, but will the bigger pipe be? If the bigger pipe is only half full of flowing water...
Hi,
Can Someone Elaborate the fluid(water) Characteristics Such as Velocity n pressure When it passes through a divergent Part. Actually The Fluid is pumped Out from A 0.5HP Centrifugal Pump and then made to pass through a Divergent Part.
Author: John D. Anderson
Title: Computational Fluid Dynamics: The Basics with Applications
Amazon Link: https://www.amazon.com/dp/0070016852/?tag=pfamazon01-20
Prerequisities: Calculus, Introductory Physics and/or Aerospace Engineering, Fluid Mechanics, Heat Transfer
Level...
We are beginning a project in my Intermediate Fluids class to make a program that can do aerodynamic analysis on an air foil. First, given any three nodal coordinates (x,y) of a triangle, we must write a program to compute its surface vectors and area of the triangle. The nodes will be in...
Hi guys and girls,
I hope you can help an electronics engineer out of his place in the mechanical world:rolleyes:
My very basic question is for a vessel holding a liquid at a given pressure and a given opening in the vessel how can i calculate exit velocity and mass flow rate? Like if i...
Hey everyone, I'm a second year undergraduate student in aerospace engineering and I've been learning a bit of quantum mechanics for the past few weeks, for recreational purposes.
I've been following this textbook: http://www-thphys.physics.ox.ac.uk/people/JamesBinney/qb.pdf
On pages 40-41...
Walking round a local amenity area today brought this photo of a side stream cut off by the local river in spate flowing past from left to right in the picture.
The river water is reddy brown and the side stream grey-green.
The two waters are not mixing as can be seen by the well defined...
Can anyone give me some advice on where I should take my points of reference when using bernulli equation. I know the point will vary according to the problem, but can one say, always begin looking for this and that and apply the equation... Then move to this and that, etc
I am working on hobby project with almost no budget.
I bought some "nice" (cheap & simple) electronic solenoid valves for water flow. I've since discovered that they need 3PSI to open. Which is ok for the supply lines. But the drain line requires that as well. Now I either need a column of water...
Homework Statement
A cube of side 5cm is placed in a fluid. For the following velocity values, calculate the average divergence of the flow. Is there a source or sink within this box? The velocities are given in cm/s. The cube is oriented so that the +z axis exits the front face, the +x axis...
The basic idea is to package an egg so that it will not break when I drop it off a roof (assume 10m tall). The packaging should be as small and lightweight as possible. I know using a fluid will be rather heavy, but I'm still curious about his.
How would I determine the optimal fluid to use? I...
Hi,
I'm looking at the solution to a question on fluid flow through a rigid pipe.
Original equation: \mu u = 0.25r^{2} dp/dx + Aln(r) + B
After applying boundary conditions: \mu u = 0.25dp/dx (r^{2} - a^{2})
I don't understand how the constants have been solved for. Below is as far as I get...
I am trying to understand how the Lorentz force affects bulk fluid motion when I have an applied electric field (y-axis), applied magnetic field (x-axis) and bulk fluid velocity (z-axis), all orthogonal to each other.
I understand that if the fluid was at rest, an electrostatic force would...
Hi all,
For an exam I'm required to be able to plot the PDF of a fluctuating velocity function, say u(t)=sint(wt), using what they call the "graphical technique", but handily I can't find it anywhere in the lecture notes, and I'm struggling to find anything with a standard Google search...
I am trying to understand how the Lorentz force affects bulk fluid motion when I have an applied electric field (y-axis), applied magnetic field (x-axis) and bulk fluid velocity (z-axis), all orthogonal to each other.
I understand that if the fluid was at rest, an electrostatic force would...
I've rencently been thinking about several systems related to fluid mechanics, and I've asked myself the following question:
If I have a cylidrical tank with a small hole in the bottom (the surface area of the hole is small in comparison with that from the tank) and I'm filling the tank with...
Hi. I was asking myself the following question.
What happens if I have a fluid at rest inside a container, and I introduce my finger in it without applying any force to the walls? Will the weight of the whole system change?
My intuition says no (If I don't exert a force on the fluid this...
Need help on basic fluid volume calculation!
Hey guys, I need some help calculating a volume.
Ok, so say we are given a pressure vessel with an 88ci volume @ 4500psi which is then regulated down to 100psi and we open a valve for 0.1 second. How many cubic inches of air would be released...
the probem is from the book:
Fundamental mechanics of fluids by I.G. Currie
is from the chapter 4 ( 2 dimentianal potential flows )
is the problem 4.4:
. Consider a source of strength m located at z = −b , a source of strength m
located at z=- a^2 / b , a sink of...
hi all,i have recently started studying a subject heat transfer,in which i learned that there are two types boundary layers.one is velocity boundary and other is temperature boundary layer..now my question is that..boundary layer thickness increases in flow direction,what is the physical...
Homework Statement
A shaft of diameter 74.9mm rotates at 1400rpm in a bearing which is of diameter 75.03 mm and 75mm in length. The annular space between the shaft and the bearing is filled with oil of viscosity 0.096 kg/ms.By assuming a uniform velocity gradient in the oil, determine the...
1. The problem statement...
The textbook I am using states that an idealized fluid cannot sustain a force tangential to its surface. Can anyone expound upon this argument? This statement is an introductory exploration of pressure and is cited as the reason that the force dF exerted by its...
I am interested to know what book(s) others would recommend to someone aspiring to learn fluid mechanics from and what kind of preparation would be required for that book.
I am an undergraduate student and have completed courses in single and multivariable calculus, linear algebra, ordinary...
fluid mechanics: defition of "shear flow" [rate of deformation tensor]
I'm studying old undergraduate chemical engineering notes for an exam in grad school. Can't recall what this really means, can anyone explain to me what "off-diagonal elements" means and why the trig function velocities...
This may sound like a basic question, but it's just to get it clear:
When describing fluid flows, does the term "incompressible" mean exactly the same thing as "constant density"?
I was under the impression that if a fluid cannot be compressed, then its density must remain constant for any...
QUESTION
Rainwater collects behind the concrete retaining wall shown in the figure. If the water saturated soil (specific gravity 2.2) acts as a fluid, determine the force and center of pressure on a 1-m width of the wall.
PROBLEM
1. What does it mean by 1-m width of the wall? Is it 1-m...
Hi, I am trying to work with the problem of keeping a solid body at equilibrium over an orifice.
To see what I mean ( not necessarily a sphere could be a cube or something like that as well ) please look at the image I have attached.
I am trying to work with the sphere case first and then...
Homework Statement
Consider a bucket quarter filled with oil. When the bucket is rotating with the angular velocity ω, derive the equation of the surface h(x), where h is measured from the lowest of the surface and x is measured from the rotational axis. Does it change if we replace oil by...
Hi, I am a mechanical engineer, therefore I am no very experienced in chemistry
I need to find a fluid similar to lubrificant oil in density and viscosity, but with low oiliness
I thought to gasoline, but it is very dangerous for my aim. I have to test on the production line some components...
Homework Statement
A cork is held at the bottom of a bucket of
water by a piece of string. The actual depth
of the cork is 0.713786 m below the surface of
the water.
If the density of the cork is 157 kg/m3
and the volume of the cork is 3 cm3
, then what is the tension in the string...
Hi all, I know that for low speeds, the fluid resistance is F=kv while at high speeds, it's F= Dv^2. However, how do I ever know what is defined as a low speed and high speed? This kind of explanation is so qualitative and I think a quantitative one is better. Thanks all!
I've been attempting my Physics homework and realize I have no idea how to do any of the problems. Instead of asking each of them, I figured I'd ask if anyone knew where I could find a general lesson plan for this section. Here are some of the problems. All help is appreciated :).
1) A...
You have this loop of water (or some other "incompressible" fluid) with a nuclear powered water pump that constantly pumps the water in a circle. This loop is slowly lowered near the event horizon of a black hole, let's even make it a super duper massive black hole to minimize tidal effects...
Homework Statement
water in main pipe at the street level is at a gauge pressure of 170 KPa and is moving with neglibible speed. A pipe connected to the main pipe is used to deliver the water to kitchen located on the third floor of a building, at a 15-m height from the street level. what is...
Hello, and thank you kindly for considering my question.
Background: Medical needles come in gauges such that a smaller gauge represents a larger needle.
Scenario: Doctor Jack says "18 gauge needles are best for this procedure", but Doctor Jane says "27 gauge needles are best because...
Homework Statement
Hi guys,
I'm pretty new here, and long story short, I'm struggling a bit on a fluid mechanics question I've been doing for some revision.
A shaft 70 mm in diameter is being pushed at a speed of 400 mm/s through a bearing sleeve
70.2 mm in diameter and 250 mm long...
Homework Statement
Liquid 1 (density ρ_{1} = 8290 kg/m³) is poured into a large open cylinder to a depth of d_{1} = 85.9 cm. Liquid 2 (density ρ_{2} = 5695 kg/m³) is then poured on top of liquid 1 to a depth of d_{2} = 70.3 cm. Then liquid 3 (density ρ_{3} = 2933 kg/m³) is poured on top of...
Homework Statement
A velocity field is given by \vec{V}= [Ax^{3} + Bxy^{2}]\hat{i} + [Ay^{3} + Bx^{2}y]\hat{j}; A=0.2 m^{-2}s^{-1}, B is a constant, and the
coordinates are measured in meters. Determine the value and
units for B if this velocity field is to represent an incompressible
flow...
Hello there ,
could you please explain to me what would happen to an inviscid/viscous incompressible flow (energy,momentum and entropy wise)falling from a height ? ( i.e a dam )
Thanks;)
Homework Statement
A large cylindrical tank has a hole of area A at its bottom. Water is poured in the tank by a tube of equal cross-sectional area A ejecting water at the speed v
a)The water level in the tank will keep on rising.
b)No water can be stored in the tank.
c)The water level...
I am trying to come up with a shape or design of a simple piston with holes that will allow fluid to flow in one direction better than the other. Very Simple shock design.
I have tried tapered holes so as to speed up flow in one direction and it worked slightly but haven't quite found the...
Homework Statement
A piece of wood is floating in water kept in a bottle. The bottle is connected to an air pump. Neglect the compressibility of water. When more air is pushed into the bottle from the pump, the piece of wood will float with
a)larger part in the water
b)lesser part in the...
This is the question
The flow of a fluid between two large flat parallel plates normal to the y direction is fully developed and steady. The plates are a distance 2h apart in the y direction and the velocity profile, assuming y=0 is at the midpoint between the plate is V(y) = V_0(1-(y/h)^2)...