Principles of Engineering

 

Fluid Systems

Fluid - The medium used to transfer power can be a liquid or a gas. 

  • Pascal's Law:  A law that states when a force is exerted on a fluid, the fluid transfers this force equally against the walls of the vessel.

Blaise Pascal The pressure can be calculated with the formula:  

 or F = p x A
  • p = pressure (psi)
  • F = force (pound)
  • A = area (square inch)

  • Charles Law:  The volume of a gas at a constant pressure is directly proportional to its temperature.

Jacques Alexandre César Charles \frac{V_1}{T_1} = \frac{V_2}{T_2} \qquad \mathrm{or} \qquad \frac {V_2}{V_1} = \frac{T_2}{T_1} \qquad \mathrm{or} \qquad V_1T_2 = V_2T_1

  • V1 = initial volume

  • V2 = resulting volume

  • T1 = initial absolute temperature

  • T2 = resulting absolute temperature

  • Boyle's Law:  The volume of a gas at a constant temperature is inversely proportional to its pressure.

Robert Boyle

  • P1V1 = P2V2

  • Were P = Pressure and V =Volume

  • Bernoulli's Principal:  A change in the velocity of a fluid caused by a constriction produces an opposite change in pressure.

Bernoulli

  • As the speed of a moving fluid (liquid or gas) increases, the pressure within that fluid decreases.

Dynamics - The behavior of matter when in motion; (physics) the study of why objects move.

  • Fluid Power

    

  • Basic Pneumatics - uses air 
    • In pneumatic systems, force is produced by air pressure acting on the surface of a piston or valve. 

      Air is a colourless, odourless and tasteless gas consisting of approximately 78% Nitrogen and 20% Oxygen. The remaining 2% consists of about 1% Argon and a mixture of other trace elements such as helium, hydrogen and neon. 

      Compressed air is produced in a compressor and stored in a receiver.  From here it is routed to valves which control the direction of fluid flow, flow control valves which control the amount of power produced by the cylinders which convert the potential energy of the compressed air into kinetic energy at the output.

      The physical behaviour of a fluid was first discovered by Blaise Pascal. Pascal found that when a force is applied to the end of a container of liquid, the force is transmitted 

Pneumatics - Uses Air

  • Basic Hydraulics  - uses oil or water
    • In the hydraulic technology we transmit and control forces and velocities by transmitting and controlling pressure and flow. In nearly every kind of technology we use hydraulic drive and control techniques. A few examples are:
      • mechanical engineering
      • car technology
      • agriculture technology
      • earthmoving and mining technology
      • ship building technology
      • offshore-technology
      • aircraft and spacecraft technology
    • Hydraulic Fluid - A liquid that is used in hydraulic systems to transfer energy; usually an oil-based substance

    

  • Brakes

     Hydraulics - Uses Oil or Water