1. EGR 4347 Analysis and Design of Propulsion Systems
Review

2. Explain the difference between units and dimensions.
EGR Review
Explain the difference between units and dimensions.
Dimensions – physical quantity that can be characterized EX. length, mass
Units – arbitrary magnitudes assigned to the dimensions EX. meter, feet
December 6, 2018
EGR 4347

3. Explain extensive and intensive properties.
EGR Review
Explain extensive and intensive properties.
Extensive depends on system
Intensive is independent of system
December 6, 2018
EGR 4347

4. EGR Review
Give at least four forms of energy which make up the term total energy, E.
Thermal Mechanical
3. Potential Electric
Chemical Nuclear
Kinetic Magnetic
December 6, 2018
EGR 4347

5. English Engineering - slug
EGR Review
Give the unit of mass in the SI, Old English and English Engineering system.
SI - kg
Old English - lbm
English Engineering - slug
December 6, 2018
EGR 4347

6. What is gc and how is it used? Conversion constant - used with mass
EGR Review
What is gc and how is it used?
Conversion constant - used with mass
What is a simple compressible substance?
The only important reversible work mode is volume change or pdv work.
December 6, 2018
EGR 4347

7. What is the state postulate?
EGR Review
What is the state postulate?
The state of a simple compressible system is completely specified by two independent, intensive properties.
December 6, 2018
EGR 4347

8. EGR 4347 - Review What is a perfect or ideal gas (physical meaning)?
No dissociation
Intermolecular forces negligible
Occurs at low pressures and high temperatures (compared to critical point)
What is the ideal gas law?
P =  R T
December 6, 2018
EGR 4347

9. Explain R in the ideal gas law.
EGR Review
Explain R in the ideal gas law.
Specific Gas Constant-depends on molecular weight
Give the equation for and define the Conservation of Mass.
dm/dt = 0
December 6, 2018
EGR 4347

10. Give the equation for and define Continuity.
EGR Review
Give the equation for and define Continuity.
December 6, 2018
EGR 4347

11. Give the equation for and define 1st Law for a Control Volume.
EGR Review
Give the equation for and define 1st Law for a Control Volume.
December 6, 2018
EGR 4347

12. Give the equation for and define the 2nd law for a Control Volume.
EGR Review
Give the equation for and define the 2nd law for a Control Volume.
December 6, 2018
EGR 4347

13. EGR 4347 - Review Define adiabatic. No heat interaction.
Define reversible.
A process that can be reversed without leaving any trace on the surroundings.
Define isentropic.
ds=0
December 6, 2018
EGR 4347

14. Is an adiabatic, reversible process isentropic? Yes
EGR Review
Is an adiabatic, reversible process isentropic?
Yes
Is an isentropic process always adiabatic and reversible? No
Is an isentropic, adiabatic process reversible?
December 6, 2018
EGR 4347

15. Is an isentropic, reversible process always adiabatic? No
EGR Review
Is an isentropic, reversible process always adiabatic? No
What is a calorically perfect gas?
cp/cv = constant = 
For a calorically perfect gas what is du?
du=cvdT
December 6, 2018
EGR 4347

16. For a calorically perfect gas what is dh? dh=cpdT
EGR Review
For a calorically perfect gas what is dh?
dh=cpdT
What is Gibbs Equation?
Tds=dh-vdp=du+pdv
What is specific enthalpy?
h=u+pdv
December 6, 2018
EGR 4347

17. Define total properties.
EGR Review
Define total properties.
Fluid brought to rest isentropically (or adiabatically)
Write the equation for total enthalpy and total temperature.
ht=h+V2/(2gc) Tt=T+V2/(2gccp)
December 6, 2018
EGR 4347

18. EGR Review
Explain the concept of isentropic efficiency as it applies to a turbine.
December 6, 2018
EGR 4347

19. Draw the T-s diagram showing Turbine Isentropic Efficiency.
EGR Review
Draw the T-s diagram showing Turbine Isentropic Efficiency.
December 6, 2018
EGR 4347

20. Derive cp = cv+ R from h = u + pv using the ideal gas law
EGR Review
Derive cp = cv+ R from h = u + pv using the ideal gas law
h = u+pv = u+RT
dh = du + RdT +TdR dR=0
dh/dT = du/dT + R
cp = cv + R
December 6, 2018
EGR 4347

21. V/a where a is the speed of sound
EGR Review
What is Mach number?
V/a where a is the speed of sound
Using Gibbs equation Tds = du + pdv find
s = cv ln(T2/T1) + R ln(v2/v1).
December 6, 2018
EGR 4347

22. Find the following in terms of  using cp=cv+R 1) R/cv
EGR Review
Find the following in terms of  using cp=cv+R
1) R/cv
R/ cv = (cp/ cv) - 1 =  - 1
2)R/ cp
R/ cp = 1 - (cv / cp) = 1 - (1/  ) = ( - 1)/ 
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EGR 4347

23. (cv - R)/ cp = (cv / cp) - (R / cp) = 1/ - ( -1) /  = (2- )/
EGR Review
3) (cv - R) / cp
(cv - R)/ cp = (cv / cp) - (R / cp) = 1/ - ( -1) /  = (2- )/
4) (cv - R) / cv
(cv - R)/ cv = 1 - ( - 1) = 2 - 
December 6, 2018
EGR 4347

24. EGR Review
Use s = cp ln(T2/T1) - R ln(p2/p1) to find the isentropic relationship for pressure and temperature
cp ln(T2/T1) = R ln(p2/p1)
ln(T2/T1) = (R/cp ) ln(p2/p1) R/cp=(-1)/
raise “e” to this power
(T2/T1) = (p2/p1) (-1)/
December 6, 2018
EGR 4347

25. Use Tt=T+V2/(2gccp) to find Tt/T in terms of  and Mach number
EGR Review
Use Tt=T+V2/(2gccp) to find Tt/T in terms of  and Mach number
V = M a where a is SQRT(gc RT)
Tt=T+M2 RTgc /(2gccp)
(Tt/T) = 1 - M2 ( R)/(2cp) R/cp=(-1)/
(Tt/T) = 1 - M2 (-1)/2
December 6, 2018
EGR 4347