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• Thermal-Fluid Sciences


  The physical sciences that deal with energy and the transfer, transport, and conversion of energy
• Thermal-fluid sciences subcategories


  • Thermodynamics
  • Aircraft and spacecraft
  • Power plants
  • Heat transfer
  • Refrigerator
  • Cars
  • Wind turbines
  • Fluid mechanics
  • Food processing
  • Boats
• Thermodynamics


  The science of energy
• Energy


  The ability to cause changes
• Conservation of energy principle

  • During an interaction, energy can change from one form to another but the total amount of energy remains constant
• Energy forms


  • Potential energy
  • Kinetic energy
• Energy cannot be created or destroyed; it can only change forms (the first law)
• Heat


  The form of energy that can be transferred from one system to another as a result of temperature difference
• Heat Transfer


  The science that deals with the determination of the rates of such energy transfers and variation of temperature
• Thermodynamics is concerned with the amount of heat transfer as a system undergoes a process from one equilibrium state to another, and it gives no indication about how long the process will take</b>
• Fluid Mechanics


  The science that deals with the behavior of fluids at rest (fluid statics) or in motion (fluid dynamics), and the interaction of fluids with solids or other fluids at the boundaries
• System


  Quantity of matter or a region in space chosen for study
• Types of systems


  • Closed
  • Open
• Surroundings


  The mass or region outside the system
• Boundary


  Real or imaginary surface that separates the system from its surroundings
• Types of boundaries


  • Fixed
  • Movable
• Closed system (control mass)

  Fixed amount of mass, and no mass can cross the boundary. But energy, in the form of heat or work, can cross the boundary. The volume of a closed system does not have to be fixed.
• Isolated system


  A special case of a closed system where even energy is not allowed the boundary
• Open system (control volume)

  A properly selected region in space. Both mass and energy can cross the boundary of a control volume.
• Control surface


  The boundaries of a control volume and they can be real or imaginary
• Property


  Any characteristic of a system
• Types of properties


  • Intensive properties
  • Extensive properties
• Intensive properties


  Properties that are independent of the mass of a system, such as temperature, pressure, and density
• Extensive properties


  Properties whose values depend on the size-or extent-of the system, such as total mass, total volume, total momentum
• Specific properties


  Extensive properties per unit mass
• Continuum


  Matter is made up of atoms that are widely spaced in the gas phase. Yet it is very convenient to disregard the atomic nature of a substance and view it as a continuous, homogeneous matter with no holes, that is a continuum.
• The continuum idealization allows us to treat properties as point functions and to assume the properties vary continually in space with no jump discontinuities.
• This idealization is valid as long as the size of the system we deal with is large relative to the space between the molecules.