Fluid Definition and 1000 Threads

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.

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  1. J

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    1. A sphere 1 ft in diameter is moving horizontally at a depth of 12 ft below a water surface where the water temperature is 50F. Vmax = 1.5Vo, where Vo is the free stream velocity and occurs at the maximum sphere width. At what speed in still water will cavitation first occur? Given: speed...
  2. M

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  3. V

    How Does Downstream Restriction Affect Upstream Water Levels in Fluid Mechanics?

    Dear Friends, I need some ideas on a problem I am facing at work. I have attached a sheet with has a rough picture of scenario. I urge you to please keep open the picture while reading my problem. Problem:- There is a small wall in a water stream. Due to the small wall the water stream upside of...
  4. P

    Pipe Flow Rate: Guarantee Constant Volumetric Flow

    I have a pipe with regular diameter connected to a tap, the water comes from public supply, I assume that public supply can vary on pressure and flow rate. How can I guarantee that I allways get the same volumetric flow rate at the end of the pipe? Will a pressure reducer be sufficient? Thank you!
  5. B

    Theoretical Fluid Mechanics - Ideal Fluid Flow

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  6. D

    Applied pressure through fluid to measure strain

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  7. M

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  8. D

    Measuring Flow Velocity in Pipe Expansion: Laminar vs. Turbulent | Explained

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  9. L

    Fluid dynamics problem -- Tanks Connected by Capillary

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  10. A

    Two Balls Drop, what happens to the distance?

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  11. U

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    Hi All, Recently we've been working on the distinction between the Eulerian and Lagrangian approaches in Fluid mechanics. I understand the simpler examples like a running stream of hot water etc. However one example is really tripping me up. So what's confusing me is that in analyzing...
  12. T

    Fluid mechanics self-studying book

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  13. F

    Calculating Minor Head Losses in a Fluid System

    I have a question where I have to find minor head losses for a system using both the equivalent length method and number of velocity heads method . It will not let me attatch the drawing here but , a liquid is to be pumped from an underground vessel (which is vented) to a pressurissed...
  14. S

    Fluid mechanics modeling question

    Physics Forum: Can someone show me how to model, mathematically, what happens if you place a drink box with a straw sticking out of it, in a vacuum chamber and apply a vacuum?
  15. E

    How Does Blood Pressure Change with Velocity in Fluid Mechanics?

    I have a question about fluid mechanics. I know it's not completely physics, but in the end, it involves physics: Suppose you are computing the blood flow in an artery segment with length 3 cm and diameter 3 mm. The artery has a constant cross section and its positioned horizontally in your...
  16. C

    Fluid dynamics - find distribution of a conserved variable

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  17. T

    Fluid statics - two water tanks

    Homework Statement A water tank, 3.7 m deep and 2 m in diameter, is connected at the bottom to a second water tank by using a 2 cm diameter pipe (see the figure). The tank A is open to the air and tank B is filled to the top and sealed. a) what is the mass of the water in tank A...
  18. R

    Areas Of Reasearch in Fluid Mechanics & Mechanical Design

    Hello! My friend and i are interested in doing a project.My area of interest in Fluid mechanics and my friend's is mechanical design can you guys help us out by providing some topics of research which encircles both these areas.
  19. Kaustubh sri

    See an object clearly in fluid like water

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  20. H

    Fluid Forces & Buoyancy: Why is There a Force Pushing Up?

    Homework Statement There is a figure of a cylinder of liquid partially immersed in a beaker of a fluid. Why is there a force that pushes up on the cylinder of liquid in the beaker? Multiple choice: 1. The weight of the liquid cylinder and the atmospheric pressure acting on the cylinder is...
  21. TheTank

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  22. F

    Calculating Minor Head Losses for Pumped Liquid System | Fluid Dynamics Question

    I have a question where I have to find minor head losses for a system using both the equivalent length method and number of velocity heads method . It will not let me attatch the drawing here but , a liquid is to be pumped from an underground vessel (which is vented) to a pressurissed...
  23. W

    Why should people with congestive heart failure drink less fluid?

    People with congestive heart failure (CHF) are advised by doctors to restrict fluid intake. For example, while 8 cups of fluid per day is recommended for healthy individuals, people with CHF are recommended not to exceed 4 cups a day. The explanation, according to a medical student friend, is so...
  24. G

    Optics and fluid dynamics simulation software

    I am doing "Schlieren imaging" visualization of a gas flow from the nozzle. could anyone please recommend a software to simulate a gas flow from the nozzle. in addition please recommend a software to simulate optics, like the propagation of a light beam through the optics and image...
  25. M

    Help solving / check fluid force

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  26. D.R.U

    Why fluid transmit for or less force ? Why it is not act like rigid bo

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  27. F

    Fluid Dynamics Question - Pressure Difference in Horizontal Pipe

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  28. H

    If density of object is slightly greater than density of fluid?

    I know that if density of an object is equal to density of fluid, the object will be fully submerged hovering right underneath the fluid. My questions related to this concept are: 1. If the density of the object is extremely slightly greater than the density of the fluid, will the object look...
  29. M

    Would Fluid Droplets Land in the Same Position in a Vacuum?

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  30. Cygnus_A

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  31. Rugile

    Archived Fluid statics and relative humidity problem

    Homework Statement A tube (both ends open, height h, diameter d) is immersed into water so that length h1 of the tube is above water. Then the top of the tube is covered tightly and the tube is pulled out of the water so that length h2 is above water. The relative humidity of air is \phi and...
  32. K

    Fluid flow out of pressurized vessel

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  33. duhuhu

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  34. F

    Fluid mechanics: books and other learning resources

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  35. J

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  36. E

    Coaxial Cylinders Flow: Examining Velocity & Stress in a Rotating Fluid

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  37. M

    The impact of a rope versus the stagnation pressure of a fluid

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  38. P

    Specific gravity of mystery fluid

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  39. N

    "Violation of Bell's inequality in fluid mechanics"

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  40. Z

    Why incompressible fluid flow is advantageous in numerical computation

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  41. M

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  42. Z

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  43. D

    Fluid Flow out of a Liquor Bottle

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  44. S

    Find the potential of a fluid with varying density

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  45. M

    Exploring Pressure Energy in Incompressible Fluid Flow

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  46. M

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  47. P

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  48. T

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  49. B

    Calculating Liquid Height Difference in U-Tube | Fluid Mechanics Homework

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  50. C

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