Quiz 1

• Thermal-fluid sciences is the physical sciences that deal with the energy and the transfer, transport, and conversion of energy.
• Thermodynamics is the science of energy. It also deals with the change of the total energy.
• Energy is 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
• The first law of thermodynamics states that energy can be transferred from one form to another, but it cannot be created or destroyed. It is an expression of the conservation of energy principle.
• The second law of thermodynamics states that the entropy of a closed system always increases. Hot things always cool unless you do something to stop them.
• Classics thermodynamics is a macroscopic approach to the study of thermodynamics that does not require a knowledge of the behavior of indivdual particles.
• Heat is the form of energy that can be transferred from one system to another as a result of temperature difference
• Heat transfer is 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.
• Closed system is also known as control mass. A fixed amount of mass, and no mass can cross its boundary.
• Open system is also known as control volume. A properly selected region where both mass and energy can cross the boundary.
• Control surface is the boundary of the control volume
• Intensive properties are those that are independent of the mass of a system, such as temperature, pressure, and density.
• Extensive properties are those values that depend on the size or extent of a system.
• Specific properties are extensive properties per unit mass.
• Continuum disregards atomic nature of a substance and assumes it as continuous, homogeneous matter with no holes.
• Based on Bernoulli’s principle, when a fluid accelerates through a pump it loses pressure
• Thermal equilibrium is the same throughout the entire system.
• Mechanical equilibrium is when there is no change in pressure at any point of the system with time.
• Phase equilibrium is if the system involves two phases and when the mass of each phase reaches equilibrium level and stays there.
• Chemical equilibrium is when the chemical composition does not change with time and no chemical reactions occur.
• Two independent, intensive properties are needed to determine thermodynamic states.
• The difference between the absolute pressure and the local atmospheric pressure is called gage pressure.
• Isothermal = Temperature remains constant in the system.

  Isobaric = Pressure remains constant in the system.

  Isochoric (or Isometric) = Specific volume remains constant in the system.
• There are only two forms of energy interactions associated with a closed system which are heat transfer and work.
• An energy interaction is heat transfer if it’s driving force is a temperature difference. Otherwise, it is just work.
• Conduction is the transfer of heat energy from one object to another through the movement of particles.
• In Convention, heat transfer takes within the fluid.
• Radiation (Heat Transfer Mechanisms)

  Heat transfer occurs through electromagnetic waves without involving particles
• Systems possess energy but not heat or work. Both are associated with a process, not a state.
• If energy is crossing the boundary of a closed system and it's not heat, it must be work.
• Efficiency is equal to

  Desired output over required input.
• Mechanisms of energy transfer?

  1. Heat Transfer
  2. Work Transfer
  3. Mass Flow
• What is the change of the total energy of a system for any process equal to?

  Difference between the total energy entering the system minus the total energy leaving the system.
• What is the Ideal Gas Law?

  PV = RT
• what is the compressibility factor Z in terms of ideal-gas law behavior?

  Z = PV/RT or Z = Actual Volume divided by Ideal Volume
• State the number locations

  1. Compressed Liquid
  2. Saturated Liquid + Gas
  3. Superheated Gas Vapor
  4. Critical Point

  
• Pure substance?

  A substance that has a fixed chemical composition throughout
• Triple point is when what happens?

  All 3 phases coincide.