UNIQUE & UPDATED

1.Heat supplied at constant pressure = change in enthalpy.
2. Heat supplied at constant volume = change in internal energy.
3. ‎For ideal gas enthalpy is a function of temperature only.
4. For ideal gas internal energy is a function of temperature only.
5. In constant pressure process, when heat is given to an ideal gas it will expand and do some work and it's internal energy also increases so temperature will also increases ( During expansion ) and ultimately enthalpy will also increases.
6. If piston is free to expand when we add heat to a gas contained in a piston cylinder arrangement then it is a isobaric process.
If there is a constant load on piston and it is also expanding when we are adding heat then it is also a isobaric process. the condition is that load should not vary with the displacement of piston.
6. During constant volume heat addition both  pressure and temperature increases and vice versa.
7. If adiabatic process is carried without insulation it MUST be very fast.
However with insulation whether slow or fast process become adiabatic.
8. Isobaric heat addition is a process of expansion and vice versa. During isobaric heat addition both temperature and volume increases and vice versa.
9. Isothermal heat addition is a process of expansion and vice versa.
10. Isothermal process with gas MUST BE VERY SLOW. however, IT CAN BE FAST DURING PHASE CHANGE.
11. Use PV=MRT ( very very very very helpful to compare processes )
12. The value of specific heat is -ve for polytropic process it means when we give heat to a system it's temperature will decreases instead of increasing. This is because gas do some extra work by giving it's internal energy so it's temperature decreases.
13. The value of n ( in PV to the power n = Constant) lies between -infinity to + infinity.
14. All the processes are polytropic processes.
15. in THERMODYNAMICS we are more interested in those processes for them value of n lies between 1 to gama. But it's actual value is -infinity to + infinity ).
16. The value of specific heat at constant pressure is always greater than specific heat at constant volume. And there ratio is called specific heats ratio. and there difference is characteristics gas constant.
17. Heat and work transfer are ways of energy interaction.
18. Energy is a property and independent of the path followed.
19. PMM 1,2,3 are impossible. PMM is just a hypothetical machine.
20. Energy of an isolated system always remains constant.
21. The entropy of an isolated system can never decrease. Eg. Universe.
22. System boundary has zero thickness, no mass and no volume. It may be fixed or moving. It may be real or hypothetical.
23. INTENSIVE PROPERTIES:
            1. Pressure
            2. Temperature
            3. Density
            4. Viscosity
            5. Velocity
            6. MP
            7. BP
            8. specific enthalpy
            ‎9. Specific entropy
            ‎10. Specific internal energy
            ‎11. Specific heat
            ‎12. Specific volume
            ‎13. Specific energy
            14. Thermal conductivity
          
24. EXTENSIVE PROPERTIES:
            1. MASS
            2. volume
            3. energy ( I.E., K.E., P.E., )
            4. Enthalpy
            5. Entropy
            6. Electric charge
            ‎7. Magnetization
            ‎8. Heat capacity
            ‎
25. Triple point of water 0.01 degree centigrade ( 273.16 K ) and 0.6112 kpa or 4.58mm of Hg. Triple point is a  Fixed point of thermometry.
26. Critical temperature and pressure for water =
               374.15 degree centigrade or
               647.30K
                221.2 bar
                Critical specific volume= 0.00317 meter cube per kg
27. Zeroth law was given by R.H. Fowler in 1931.
28. Zeroth law is the basis of temperature measurements and it comes 82 years after 1st law.
29. HEAT AND WORK ARE NOTHING................THEY ARE ONLY THE WAYS IN WHICH ENERGY INTERACTION TAKES PLACE.
Mass transfer is also a way of energy transfer.
30. Internal energy consists of SENSIBLE ENERGY, LATENT ENERGY, CHEMICAL ENERGY AND NUCLEAR ENERGY.
ALL ARE MICROSCOPIC FORMS OF ENERGY.
U = SUM OF ALL THESE 4 ENERGIES.
31. ALL properties like P,V,T,U,H,S are point functions.
32.  Gama ( adiabatic index ) = 1.67 for monoatomic gases like He.
1.4 for diatomic gases like air, oxygen.
1.33 for triatomic gases like carbon Di oxide.
33. Maximum density of water is 1000 kg per meter cube. ( At 4 degree centigrade )
34. Generally all the engineering devices like steam turbine, gas turbine, air compressor, pump, condenser, IC ENGINES are OPEN SYSTEMS.
35. 1MM HG = 1 TORR = 133 PASCAL.
36. 1 LITRE = 0.001 METER CUBE.
37. ‎Joule-thompson coefficient Uj for an ideal gas is 0.
38. ‎in H-S diagram the constant pressure lines are straight lines in wet region.
39. ‎the slope of constant pressure lines in wet region is equal to T.
40. ‎at critical point latent heat of vaporization is 0.
41. ‎at a pressure higher than critical pressure liquid upon heated suddenly flashes into vapour.
42. ‎a substance expands on freezing only if the slope of fusion line on PT plane is negative like water.
43. ‎entropy change for a reversible adiabatic process is 0.
44. ‎there is no heat transfer in an adiabatic process.
45. ‎a mixture of ideal gas also behaves as an ideal gas.
46. ‎the temperature of an ideal gas always decreases during isentropic expansion.
47. ‎a steam turbine gives us shaft work which is also a type of mechanical work.
48. ‎first law of thermodynamics is valid for any SYSTEM and for any process.
49. ‎thermometric property in thermistor is electrical resistance.
50. ‎a thermodynamic property does not depend on the past history of the system.
51. ‎     : HEAT ENGINE CYCLES :

A. GAS POWER CYCLES :

1. Carnot cycle : 2 reversible adiabatics and 2 isotherms

2. Ericsson cycle : 2 isobars and 2 isotherms

3. Stirling cycle : 2 isothermal processes and 2 isochoric processes

4. Brayton cycle : 2 isobaric processes and 2 reversible adiabatics

5. Otto cycle : 2 reversible adiabatics and 2 isochoric processes

6. Lenoir cycle : 1 isochoric, 1 isentropic and 1 isobaric

7. Atkinson cycle : 2 isentropic processes, 1 isobaric, 1 isochoric ( ideal cycle for an Otto engine exhausting to a gas turbine )

8. Diesel cycle : 2 isentropic, 1 isobaric, 1 isochoric

9. Dual cycle : 2 isentropic, 2 isochoric and 1 isobaric

B. Vapour power cycle :

1. Rankine cycle : 2 isentropic 2 isobaric
Reheat, regeneration also used with this cycle for further modification to increase the efficiency.

P.S. Rankine cycle and brayton cycle both have 2 isentropic and 2 isobaric. But....... Rankine cycle involves phase change of working fluid I.e. water in steam power plant while brayton cycle is a gas power cycle used in gas turbines .
52. All actual processes are irreversible processes.
53. ‎for a cycle change in property is zero as initial and final states are identical.
54. ‎ideal gas thermometer is independent of material of construction.
55. ‎at triple point DOF=0
56. ‎Kg-mol = kmol
57. ‎in polytropic process heat transfer is not 0.
58. ‎nozzle increases the velocity/K.E. of fluid at the expense of its pressure drop.
59. ‎diffuser is just opposite of nozzle.
60. ‎the efficiency of all reversible heat engines operating between the same temperature levels is the same.
61. ‎the effect of decreasing T2 to increase thermal efficiency of  carnot cycle is more than the effect of increasing T1 by same amount.
62. ‎first law of thermodynamics gave origin to internal energy and second law leads to entropy.
63. ‎it is impossible by any procedure, no matter how idealized, to reduce any system to absolute zero of temperature in a finite number of operations.
This is the 3rd law of thermodynamics.
64. REVERSIBLE ADIABATIC PROCESS IS AN ISENTROPIC PROCESS BUT REVERSE IS NOT ALWAYS TRUE.
65. ‎properties are exact differentials.
66. ‎entropy generation is a path function.
67. ‎entropy generation is always a positive value.
68. ‎the first law states that the energy is always conserved quantitywise while the second law emphasizes that energy always degrade qualitywise.
69. ‎gibbs function g is applicable for open system.
70. ‎helmholtz function f is applicable for closed system.
71. transformation of solid to Vapour directly is called sublimation.
72. transformation of vapour to solid directly is called ablimation.
73. ‎pure substance is a one component system. It may exist in one or more than one phases.
74. ‎A saturation state is a state where a change of phase occur without a change of pressure and temperature.
75. ‎on PT diagram triple point and critical point both are points.
76. ‎on PV diagram triple point is a line but critical point is a point.
77. ‎minimum value of Y ( specific heats ratio ) = 1
78. ‎maximum value of Y ( specific heats ratio ) = 1.66666.
79. ‎minimum no. Of processes required for a cycle = 2
80. ‎ratio of 2 extensive properties is an intensive property
Eg.   Density = mass/ volume
81. Constant pressure thermometer - volume is thermometric property
82. ‎constant volume thermometer - pressure is thermometric property
83. ‎thermocouple - voltage is thermometric property
84. ‎mercury in glass thermometer - length is thermometric property
85. ‎∆Tf = 1.8∆T'c
86. ‎0 Kelvin = -273.15 degree Celsius
87. ‎1 calorie = 4.186 Joule
88. 1 Kelvin = ( 1/273.16th ) of the triple point of water.
89. ‎integration Pdv can only be performed on reversible path & closed system.
90. ‎ in PV plane slope of adiabatic is more than isothermal.
91. ‎in TS plane slope of isochoric is more than isobaric.
92. ‎isochoric process is also called as isometric process.
93. ‎isothermal process is also called as hyperbolic process
94. ‎isobaric process is also called as isopiestic process.
95. ‎for P=C.  ( n = 0 )
      for V=C.  ( n = infinity )
      ‎for T=C.  ( n = 1 )
      ‎for adiabatic ( n = Y )
     ‎for polytropic ( n = between 1-Y )

96. The value of n is positive in 2nd and 4th quadrant but negative in 1st and 3rd quadrant. MIND IT.
97. ‎heat and work are :
             A. Path functions
             ‎B. Inexact differentials
             ‎C. Boundary phenomena
             ‎D. Transient phenomena
98. Y = 1 + ( 2/n )
       
          where n is degree of freedom of gas molecules
          ‎its value is 3 for monoatomic gases, 5 for diatomic gases and 6 for triatomic gases
99.the value of specific heats ratio depends only on the molecular structure of the gas.
100. Cp & Cv of an ideal gas depends only on specific heats ratio and characteristic gas constant and they are independent of the temperature and pressure of the gas.
101. ‎R for air = 0.287 kj/kgK
102. ‎C polytropic = -Cv { Y-n } / { n-1 }
103. ‎free expansion is highly irreversible process and work done during free expansion is 0.
104. ‎mechanical works are of 4 types -
     A. Displacement work
     ‎B. Shaft work
     ‎C. Flow work
     ‎D. Paddle wheel work
105. Throttling process means enthalpy remains constant also called as isenthalpic process. It is also a highly irreversible process.
106. COP of HP = COP of refrigerator + 1