[Thermodynamics] Topic 1 - Introduction to Thermodynamics

124 flashcards · Other · by Ahmed Adil

1. Thermodynamics is the science of energy

2. Energy

   The ability to cause change

3. Thermodynamics is the conversion of heat energy into mechanical energy

4. The first law of thermodynamics

   Energy is a thermodynamic property – energy cannot be created or destroyed; it can only change forms

5. These are examples of

   Conservation of energy

6. The second law of thermodynamics

   Energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy

7. Based on the second law of thermodynamics, in this case the heat will

   flow in the direction of decreased temperature

8. Classical thermodynamics (Continuum Thermodynamics): A macroscopicapproach, does not require a knowledge of the behaviour of individual particles

9. Statistical thermodynamics: A microscopic approach, based on the average behavior of larger groups of individual particles

10. Heat transfer

    The science quantifying (measure the quantity of) the rates of energy transfer and temperature variation

11. Thermodynamics: concerned with amount of heat transfer of a process. Heat Transfer: concerned with quantifying rates.

12. This is an example of

    Heat transfer

13. basic dimensions, such as mass m, length L, time t, and temperature T, are selected as primary or fundamental dimensions. while others, such as velocity V, energy E, and volume V, are expressed in terms of the primary dimensions – are called secondary dimensions, or derived dimensions.

14. Any physical quantity can be characterized by dimensions. The magnitudes assigned to the dimensions are called units.

15. Weight (N) = Mass (kg) * Gravitational acceleration (m/s^2)

16. Force (N) = Mass (kg) * Acceleration (m/s^2)

17. A quantity of matter or a region in space chosen for study.

    System

18. The mass or region outside the system

    Surroundings

19. The real or imaginary surface that separates the system from its surroundings

    Boundary

20. 1) Surroundings 2) System 3) Boundary

21. The boundary of a system can be fixed or movable

22. Systems may be considered to be closed or open

23. Closed systems are considered closed to mass but can be open to energy

24. A fixed amount of mass, and no mass can cross its boundary

    Closed system

25. Control mass

    Closed system

26. Control volume

    Open system

27. A properly selected region in space. • It usually encloses a device that involves mass flow such as a compressor, turbine, or nozzle

    Open system

28. Both mass and energy can cross the boundary of a control volume

29. The boundaries of a control volume, it can be real or imaginary

    Control surface

30. A system is called isolated when

    The mass is fixed and there is no energy exchange with its surroundings

31. Can a system contain other system inside it?

    Yes

32. Individual systems within isolated system: can exchange mass and energy with their surroundings

33. Any characteristic of a system

    property

34. Some familiar properties are

    pressure , temperature , volume , and mass

35. Properties are considered to be either intensive or extensive

36. Intensive properties: Those that are independent of the size of a system

37. Extensive properties: Those that are dependent of the size of a system

38. Specific properties

    Extensive properties per unit mass

39. 1) Extensive 2) Intensive

40. The ratio of the density of a substance to the density of some standard substance at a specified temperature

    Specific gravity SG

41. Volume per unit mass

    Specific volume

42. Weight per unit volume of a material

    Specific weight

43. A state of balance

    Equilibrium

44. If the temperature is the same throughout the entire system

    thermal equilibrium

45. If there is no change in pressure at any point of the system with time

    Mechanical equilibrium

46. If a system involves two phases and when the mass of each phase reaches an equilibrium level and stays there

    Phase equilibrium

47. If the chemical composition of a system does not change with time, that is, no chemical reactions occur

    Chemical equilibrium

48. Which type of equilibrium is this?

    Thermal equilibrium

49. The state postulate says

    The state of a simple compressible system is completely specified by two independent, intensive properties

50. A term used in thermodynamics that defines the given number of properties to a thermodynamic system in a state of equilibrium

    the state postulate

51. A system is considered to be a simple compressible in the absence of

    electrical, magnetic, gravitational, motion, and surface tension effects

52. Process

    Any change that a system undergoes from one equilibrium state to another

53. Path

    The series of states through which a system passes during a process

54. To describe a process completely, one should specify the initial and final states, as well as the path it follows, and the interactions with the surroundings

55. A process that happens slowly enough for the system to remain in internal physical (but not necessarily chemical) thermodynamic equilibrium

    Quasistatic or quasi-equilibrium process

56. The prefix iso- is often used to designate a process for which a particular property remains constant

57. Isothermal process

    A process during which the temperature - T remains constant

58. Isobaric process

    A process during which the pressure - P remains constant

59. Isochoric (or isometric) process

    A process during which the specific volume - v remains constant

60. A process during which the initial and final states are identical

    Cycle

61. The term steady implies no change with time. The opposite of steady is unsteady, or transient

62. A process during which a fluid flows through a control volume steadily

    Steady flow process

63. Steady-flow conditions can be closely approximated by devices that are intended for continuous operation, such as turbines, pumps, boilers, condensers, and heat exchangers or power plants or refrigeration systems

64. During a steady- flow process, fluid properties within the control volume may change with position but not with time

65. Under steady-flow conditions, the total mass and energy contents of a control volume remain constant

    Last blank is a type of system

66. Mass per unit volume

    Density

67. Which SI unit does the weight and force share?

    Newton N

68. How do we calculate the specific gravity in terms of specific weight

69. Weight = mass x gravity Force = mass x acceleration

70. What do we calculate with this formula?

    specific weight

71. What do we calculate with this formula? and what is the name of the symbol on the left?

    specific weight gamma

72. Specific volume = volume / mass

73. Specific volume is equal to the inverse of density

74. Write the two formulas of specific weight

    specific weight = weight / volume specific weight = density x gravity

75. What does continuum mean?

    Properties of the matter are considered as continuous functions of space variables

76. State the formula for work and mention its unit

    work = force x distance joules J

77. State the zeroth law of thermodynamics

    if two bodies are in a thermal equilibrium with a third body, they are also in a thermal equilibrium with each other

78. By replacing the third body with a thermometer, the zeroth law can be restated as

    two bodies are in thermal equilibrium with each other if both have same temperature reading even if they are not in contact

79. The triple point of water (the state at which all three phases of water coexist in equilibrium), which is assigned the value 273.16 K

80. 1 bar = 10^5 Pa = 0.1 MPa = 100 KPa

81. The actual pressure at a given position. It is measured relative to absolute vacuum (i.e. absolute zero pressure)

    Absolute pressure

82. The difference between the absolute pressure and the local atmospheric pressure.

    Gauge pressure

83. Pressures below atmospheric pressure

    Vacuum pressures

84. Energy can exist in numerous forms such as thermal, mechanical, kinetic, potential, electric, magnetic, chemical, and nuclear, and their sum constitutes the total energy E of a system

85. Thermodynamics deals only with the change of the total energy

86. Forms of energy a system possesses as a whole with respect to some outside reference frame, such as kinetic and potential energies

    Macroscopic forms of energy

87. Forms of energy those related to the molecular structure of a system and the degree of the molecular activity, such as sensible, latent, chemical, and nuclear energy

    Microscopic forms of energy

88. Internal energy, U

    The sum of all the microscopic forms of energy

89. Kinetic energy, KE

    The energy that a system possesses as a result of its motion relative to some reference frame

90. Potential energy, PE

    The energy that a system possesses as a result of its elevation in a gravitational field

91. The macroscopic energy of an object changes with velocity and elevation

92. Name the formula and state its unit.

93. We denote specific properties with small letters

94. Name the formula and state its unit.

95. Name the formula and state its unit.

96. The various forms of microscopic energies that make up sensible energy 1) Molecular translation 2) Molecular rotation 3) Electron translation 4) Molecular vibration 5) Electron spin 6) Nuclear spin

97. The internal energy of a system is the sum of all forms of the microscopic energies

98. Name these forms of energy

    1) Sensible 2) Latent 3) Chemical 4) Nuclear

99. The portion of the internal energy of a system associated with the kinetic energies of the molecules.

    Sensible energy

100. The internal energy associated with the phase of a system

     Latent energy