1 / 25

EGR 4347 Analysis and Design of Propulsion Systems

EGR 4347 Analysis and Design of Propulsion Systems. Review. EGR 4347 - 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.

jaime-houston
Download Presentation

EGR 4347 Analysis and Design of Propulsion Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EGR 4347 Analysis and Design of Propulsion Systems Review

  2. EGR 4347 - 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 EGR 4347

  3. EGR 4347 - Review • Explain extensive and intensive properties. • Extensive depends on system • Intensive is independent of system EGR 4347

  4. EGR 4347 - Review • Give at least four forms of energy which make up the term total energy, E. • Thermal 2. Mechanical • 3. Potential 4. Electric • Chemical 6. Nuclear • Kinetic 8. Magnetic EGR 4347

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

  6. EGR 4347 - 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. EGR 4347

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

  9. EGR 4347 - 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 EGR 4347

  10. EGR 4347 - Review • Give the equation for and define Continuity. EGR 4347

  11. EGR 4347 - Review • Give the equation for and define 1st Law for a Control Volume. EGR 4347

  12. EGR 4347 - Review • Give the equation for and define the 2nd law for a Control Volume. 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 EGR 4347

  14. EGR 4347 - Review • Is an adiabatic, reversible process isentropic? • Yes • Is an isentropic process always adiabatic and reversible? • No • Is an isentropic, adiabatic process reversible? • Yes EGR 4347

  15. EGR 4347 - 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 EGR 4347

  16. EGR 4347 - 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 EGR 4347

  17. EGR 4347 - 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) EGR 4347

  18. EGR 4347 - Review • Explain the concept of isentropic efficiency as it applies to a turbine. EGR 4347

  19. EGR 4347 - Review • Draw the T-s diagram showing Turbine Isentropic Efficiency. EGR 4347

  20. EGR 4347 - 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 EGR 4347

  21. EGR 4347 - 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). EGR 4347

  22. EGR 4347 - 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)/  EGR 4347

  23. EGR 4347 - 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 -  EGR 4347

  24. EGR 4347 - 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)/ EGR 4347

  25. EGR 4347 - 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 EGR 4347

More Related