Card Set Information

2011-02-08 17:39:29
Assignment one

Jet Engine Theory and Design
Show Answers:

  1. Which of the following types of engine does NOT use atmospheric air for combustion?
  2. The thrust developed by a ramjet engine is due to the increase in the air's
  3. What effect does a divergent duct have on airflow?
    An increase in pressure and a decrease in velocity
  4. Which of the following statements is a definition of the term "force"?
    Action on a body that changes its state of motion
  5. Which of the following statements is correct regarding mass and weight?
    Mass is the quantity of matter; weight is the pull of gravity on that quantity of matter
  6. Rate of doing work
  7. English measurement for mechanical power
  8. Measurement of force times distance
  9. Capacity for doing work
  10. An engine exerting 1,375 pounds of force moves a vehicle 13.5 feet in 20 seconds. What total amount of work was accomplished?
    18,562.5 foot-pounds
  11. To calculate the acceleration of a given mass, what symbol representing the force of gravity is normally used?
  12. A standard day at sea level is indicated by what condition?
    20.02 inches of mercury, 0.00% humidity, and a temperature of 59.0 degrees Fahrenheit
  13. What happens to a slug of air as the temperature increases?
    The molecules move faster, run into each other with more impact, and move further apart, decreasing air density
  14. What is the ram effect?
    More air arriving at the engine intake than the engine can ingest
  15. Newton's First Law?
  16. Newton's Second Law?
  17. Newton's Third Law?
  18. In the formula F=MxA, which of the following is a measurement unit for M (mass)?
  19. Which of the following groups of jet engines will you, as an AD, be associated with most?
    Turbofan, turbojet, turboprop, and turboshaft
  20. What total number of engine designation systems are presently in use?
  21. AC?
    Allison Chalmers
  22. BA?
    Bell Aircraft Company
  23. V?
  24. In the engine designation J79-GE-10, what does the 79 indicate?
    Air Force developed
  25. Which of the following engines has NOT completed the 150-hour qualification test?
  26. T?
  27. F?
  28. J?
  29. Which of the following designations indicates an engine sponsored by the Navy?
  30. What is the MIL-STD-879 manufacturer's letter symbol for Allison Division, General Motors Corporation?
  31. An Army-sponsored engine begins with what model number?
  32. What are the three parts of the MIL-STD-879 engine designation system?
    Type indicator, manufacturer's symbol, and model indicator
  33. Which of the following is a reason for proper air entrance (duct) design?
    To increase ram recovery while reducing pressure drops
  34. A single air entrance is more advantageous than a dual air entrance system for which of the following reasons?
    It obtains maximum ram pressure
  35. Which of the following is NOT a problem caused by the use of dual intakes on single-engine aircraft?
    More expensive construction materials
  36. During supersonic flight, what major aircraft component can NOT withstand supersonic velocity airflow?
    the engine
  37. By which of the following methods do Navy aircraft diffuse intake air during supersonic flight?

    By varying the area of the intake duct?
    By using geometrically variable intake ducts?
    By creating a shock wave in the intake duct?
    All of the above
  38. What is the primary function of the compressor?
    To suppy air to the combustion chamber iin the proper
  39. What is the advantage of a dual-entry centrifugal compressor as compared to a single-entry centrifugal compressor?
    It can be made with a smaller diameter and handle the same airflow
  40. A 10-stage, axial-flow compressor consists of what total number of (a) rotors and (b) stators?
    (a) 10 (b) 10
  41. In an axial-flow engine, by what means is high-velocity, low-pressure air converted to low-velocity, high-pressure air?
    Action of stator blades at each stage of compression
  42. What is the most serious disadvantage of the axial-flow compressor?
    High tendency to stall
  43. With reference to the axial-flow engine, the angle of attack is the angle at which the airflow
    Strikes the rotor blades
  44. What three engine operating parameters cause the airflow angle of attack to vary?
    Engine rpm, compressor-inlet temperature, and compressor discharge pressure
  45. Engine "choking" refers to which of the following terms?
    Stall due to an excess volume of air in the rear of the compressor
  46. Which of the following is NOT considered by engine manufacturers as corrective action for a front-end, low-speed, high-temperature stall?
    Installing a bleed valve(s) the middle of rear portions of the compressor section
  47. Guide vanes change the direction of the air entering and leaving the compressor in what manner?
    By swirling it as it enters and straightening it out as it leaves
  48. Bleed air for unloading the compressor during starting, cockpit pressurization and heating, engine anti-icing, fuel tank pressurization, and various other purposes is tapped from from which of the following sources?
    Different stages of the compressor, depending on the pressure and temperature needed
  49. What are two common forms of blade roots?
    Fir-tree and bulb
  50. What is the profile of a compressor blade?
    A cutout that reduces blade thickness
  51. What is the purpose of compressor blade profiles?
    to allow the compressor blade tips to rub without causing serious damage
  52. Which of the following is a disadvantage of the axial-flow compressor?
    High starting power needs
  53. Which of the following types of compressors provides greater starting flexibility and improved high-altitude performance?
    Split-spool, axial-flow
  54. What is the primary function of the combustion section?
    To burn the fuel-air mixture
  55. Approximately what percent of air entering the combustion chamber is mixed with fuel for combustion?
  56. Approximately what percentage of air entering the combustion chamber serves as flame control/
  57. Increasing fuel atomization (solution)
    (problem) Carbon monoxide emission
  58. Improving primary zone fuel-air mixing (solution)
    Visible smoke elimination (problem)
  59. During the combustion process, the emission levels of which of the following pollutants increases as the temperature increases?
    Nitric Oxide
  60. Which of the following is NOT a basic element or system of combustion chambers?
    Air pollution emission reduction
  61. Which of the following is NOT basic type of combustion chamber?
  62. Presently, what total number of combustion liners are used in jet engines using can-type combustion chambers?
    8 or 10
  63. Which of the following types of fuel nozzles are used in jet engines?
    Simplex and duplex