Beginner's Guide to Propulsion
Turbine Engine Parts - Inlets
Answers

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Note: Answers may vary slightly depending on the decimal approximation used for pi.

1. A Boeing 747 aircraft has a PW4000 engine with a 94 inch inlet diameter. Find the radius, circumference, and area of this inlet.

   radius = 47 inches

   circumference = 295.3 inches

   area = 6939.8 square inches

   
   
2. A DC-10 has a JT9D engine with a 46.7 inch inlet radius. Find the diameter, circumference, and area of this inlet.

   diameter = 93.4 inches

   circumference = 293.276 inches

   area = 6851.5 square inches

   
   
3. A Boeing MD-90 has a circular inlet with a circumference of 199.39 inches. What is the radius of the inlet?
   radius = 31.7 inches
   
   
4. The Airbus 318 has a Pratt & Whitney 6000 engine with a cross-sectional circular inlet area of 2508.5774 square inches. What is the circumference of this inlet?
   circumference = 177.5 inches
   
   
5. A commercial Boeing 777 has a large circular inlet with a 112 inch diameter. How much larger is the area of this inlet than the inlet on the Boeing 747?    (Hint: refer to problem 1)
   2912.2 sq. in.
   
   
6. The F-16 military plane has a smaller circular inlet with a 34.8 inch diameter. Calculate the radius, circumference and area of this inlet.

   radius = 17.4 inches

   circumference = 109.3 inches

   area = 951.1 square inches

   
   
7. The Boeing C-17, a military transport aircraft has a circular inlet with a circumference of 246.49 inches. Find the diameter and area of this inlet.

   diameter = 78.5 inches

   area = 4839.8 square inches

   
   
8. The F18E Super Hornet has a turbine engine with a rectangular inlet. It has dimensions of 2'4" by 3'6." Find the area of a cross section of this inlet in both square inches and square feet.

   area=1176 square inches

   area = 8.16 square feet

   
   
9. Suppose there was a F19E Super Wasp with a rectangular inlet area of 13.5 square feet. If the length is 4'6," what is the width?
   width = 3 feet
   
   
10. Write a few sentences summarizing and explaining what you learned from this activity.
    Answers will vary according to age and ability of students