Chapter 4: Combustion Chamber

Question 1

purpose of combustion chamber

Answer 1

proper mixing of fuel air and assure good combustion

Question 2

combustion chamber qualities

Answer 2

1) complete combustion
2) low total pressure loss
3) stability of combustion
4) no hot spots
5) short length
6) no flameout
7) relightability

Question 3

what must fuel be before combustion?

Answer 3

vapourised and mixed with air

Question 4

equivalance ratio formula

Answer 4

ǿ = actual fuel air / ideal fuel air

Question 5

naming of mixtures when ǿ > 1 & ǿ < 1

Answer 5

ǿ > 1: rich mixture
ǿ < 1: lean mixture

Question 6

what is the range of air fuel ratio?

Answer 6

60 - 100
(60 - 100 portion of air to 1 portion of fuel)

Question 7

types of combustion chamber

Answer 7

1) multiple can (can-type)
2) tubo-annular (can-annular)
3) annular

Question 8

where is can type combustor mainly used on?

Answer 8

older centrifugal compressor engines

Question 9

advantages of can type combustion chamber

Answer 9

1) strength & durability
2) ease of maintenance

Question 10

disadvantages of can type combustion chamber

Answer 10

1) poor use of space in chamber for cooling (ueven heat distribution)

Question 11

advantages of can-annular combustion chamber

Answer 11

1) additional structural stability
2) better ultilsation of space for cooling

Question 12

disadvantages of can-annular combustion chamber

Answer 12

1) more expensive & heaveir than can type

Question 13

which type of combustor is commonly used?

Answer 13

annular combustion chamber

Question 14

advantages of annular combustion chamber

Answer 14

1) uniform heat distribution across turbine
2) better mix of air/fuel
3) better use of cooling space

Question 15

disadvantages of annular combustion chamber

Answer 15

1) complete disassembly of engine to service chamber (inlet & compressor or turbine & exhaust)

2) structural problem from large diameter