Fluid Power

  1. Matter
    Anything that has mass and takes up space
  2. Pressure
    • Force per unit area
    • Pounds per square in
  3. Mass
    • The measure of a body’s resistance to acceleration
    • Different from but proportional to weight
  4. Weight
    The gravitational force exerted on an object
  5. Density
    Amount of mass per unit volume
  6. Atmospheric Pressure
    • Pressure due to the weight of the atmosphere above a certain point.
    • Approximately 14.7 psi at sea level
    • Lubbock is approximately 13.9 psi
  7. Specific Gravity
    • Density of a fluid referenced to:
    • Air if it is a gas
    • Water if it is a liquid
  8. Absolute Pressure
    • Referenced to a complete vacuum
    • Equals gage pressure plus atmospheric pressure for positive pressures
    • 585 psig + 14.7 psia = 599.7 psia
    • Equals Complete vacuum minus gage vacuum for vacuums
    • 29.92 in Hg – 26 in Hg = 3.92 in Hg
  9. Absolute Temperature
    • Temperature referenced to absolute zero
    • -273oC = 0 Kelvin
    • -459.7oF=0 Rankine
  10. Absolute Zero
    Point at which all molecular motion stops
  11. Equilibrium
    A state of balance between two opposing actions
  12. Compressibility
    The change in volume of a unit volume of a fluid when it is subjected to a unit change of pressure
  13. Force
    The action of one body on another tending to change the velocity of the body acted upon
  14. Friction
    • The action of one body or substance rubbing against another, such as fluid flowing against the walls of pipe
    • The resistance to motion caused by this rubbing
  15. Inertia
    The tendency of a body at rest to remain at rest, and a body in motion to continue to move at a constant speed along a straight line, unless the body is acted upon in either case by an unbalanced force
  16. Energy
    The ability or capacity to do work
  17. Fluid
    • Anything that has the ability to flow
    • A liquid or gas
  18. Thermal Expansion
    A change in the volume of a substance due to a change in its temperature
  19. Velocity
    • The rate of motion in a particular direction
    • The velocity of fluids is usually expressed in feet per second
  20. Power
    • The rate of doing work
    • The rate of expanding energy
    • Power = Work/Time
  21. Work
    • The transference of energy from one body or system to another
    • That which is accomplished by a force acting through a distance
    • Work = Force * Distance
  22. Boyles Law
    • The absolute pressure of a fixed mass of gas varies inversely as the volume, provided the temperature remains constant.
    • P1V1=P2V2
  23. Charles Law.
    • If the pressure is constant, the volume of dry gas will vary directly with the absolute temperature.
    • V1/T1=V2/T2
  24. Avogadro’s Law
    • At the same temperature and pressure, equal volumes of different gases contain equal numbers of molecules.
    • 6.023x1023 atoms per mole
    • Mole – The amount of pure substance that contains the same number of elementary entities as there are atoms in exactly 12 grams of the isotope carbon 12
  25. Dalton’s Law of partial pressures
    A mixture of several gases which do not react chemically exerts a pressure equal to the sum of the pressures which the several gases would exert separately if each were allowed to occupy the entire space alone at the given temperature.
  26. Pascal’s Law
    A pressure applied to a confined fluid at rest is transmitted with equal intensity throughout the fluid
  27. Bernoulli’s Principle
    • Pressure is inversely proportional to velocity.
    • An increase in velocity of a fluid will cause decrease in pressure
  28. Newton’s Laws
    • 1ST: A body at rest tends to stay at rest and a body in motion tends to stay in motion
    • 2ND: An imbalance of force on a body tends to produce an acceleration in the direction of the force. This acceleration is directly proportional to the force and inversely proportional to the mass of the body F=mA
    • 3RD: For every action there is an equal and opposite reaction
Card Set
Fluid Power