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WorksheetsFC QUIZ V
Total questions: 30
Worksheet time: 30mins
Burning of the propellants take place in __________
nozzle
injector
combustion chamber
engine casing
The volume of the combustion chamber is selected on the basis of which of these factors?
Mixing, evaporation and complete combustion of the propellants
Mixing and complete combustion of the propellants, but not its evaporation
Evaporation and complete combustion of the propellants, but not mixing
Mixing and evaporation but not the complete combustion of the propellants
Which of the following will aid in the selection of smaller combustion chamber volume during its design?
Slightly reactive propellants
Low chamber pressure
Injectors with moderate mixing
Possibility for complete combustion
Which of the following is true for combustion chambers with large volume and diameter?
High heat transfer rates to the walls
Smaller total area exposed to the heat
Thinner walls
Lower wall temperature
The combustion chamber mass is not a function of __________
payload mass
method of cooling
chamber pressure
nozzle area ratio
For increased operating chamber pressure, the length of the combustion chamber ________ and the nozzle throat area _________ if the diameter of the combustion chamber (assume the shape to be cylindrical) is fixed and the thrust remains constant.
increases; decreases
decreases; increases
decreases; decreases
increases; increases
What is characteristic chamber length?
Thrust chamber length without the length of the nozzle
Length of the thrust chamber as if it were a straight tube with no converging section
Total length of the nozzle
Total length of the rocket engine
Determine the chamber volume if the characteristic length of a thrust chamber is 150 cm and nozzle throat area is 0.25m2.
0.573 m3
0.735 m3
0.375 m3
0.753 m3
Typical values of L* for several bipropellants lie between __________
0.8 and 3 m
1 and 2 m
1.5 and 5.5 m
3.2 and 6.4 m
What is stay time?
Average time spent by each molecule or atom within the combustion chamber volume
Average time spent by each molecule or atom within the thrust chamber volume
Average time spent by each molecule or atom within the propellant tank after rocket take off
Average time spent by each molecule or atom within the injector manifold
What kind of propulsion is used for trajectory adjustments and attitude corrections?
Boosting propulsion
Auxiliary propulsion
Sustaining propulsion
Cryogenic propulsion
How are liquid rocket engines classified on the basis of their feed system?
Pressurized or turbopump
Restartable or single fired
Single flight or reusable
Boosting or auxiliary
The thruster is also called as _____________
combustion chamber
thrust chamber
nozzle
injector
Which of the following ways of thrust chamber cooling may use niobium metal?
Film cooling
Cooling jacket
Radiation cooling
Ablative cooling
At what temperature are the liquid oxygen and the liquid hydrogen kept in their storage tanks of the cryogenic rocket engine?
-253°C and -183°C
-183°C and -253°C
-253°C for both
-183°C for both
Determine the mixture ratio if mass flow rate of the oxidizer is 3/4 times the total mass flow rate of the combustion products.
2.5
3
2
1
If the total propellant flow rate is 24 kg/s and the mixture ratio is 2.3, determine the mass flow rate of the oxidizer.
19.67 kg/s
15.33 kg/s
12.94 kg/s
16.73 kg/s
Which of the following propellants were used in the Titan mission?
50% UDMH + 50% hydrazine
RP1
RDX
Aviation gasoline
Which of the following is not a factor considered in the selection of liquid propellant for a rocket engine?
Economic
Performance
Safety
Injector pattern
Which of the following chemical particles cannot be suspended in liquid fuel to increase specific impulse?
Boron
Beryllium
Aluminium
Fluorine
Which among the following propellants is not corrosive?
Liquid oxygen
Nitric acid
Nitrogen tetroxide
Liquid Fluorine
What is O-ring in a chemical rocket engine?
A kind of seal
A type of injector
A type of pipe network
A kind of control system
Which of the following is not a desirable property of a liquid propellant?
Low freezing point
Low specific gravity
Stability
High specific heat
What is the average specific gravity(δav) if the specific gravity of the fuel (δf) is 0.792, the specific gravity of the oxidizer is (δo) is 1.02 and the mixture ratio (r) is 4?
0.96
0.94
1.01
0.98
A good liquid propellant will have ___________
easy deterioration
resistance to deterioration
absorption of moisture
small amount of impurities
Evaporation is a major concern for _________
cryogenic propellants
monopropellants
bipropellants
solid propellants
Which of the following zones is not a part of the thrust chamber?
Atomization zone
Rapid-combustion zone
Stream tube combustion zone
Transonic flow zone
The boundaries between the discrete combustion zones inside the combustion chamber is not ________
undulating
immovable
irregular
local variations
Which of the following with regards to mixing and reaction in the combustion chamber is incorrect?
Turbulent mixing
Multiple chemical reactions
Temperature rise increases densities
Local mixture ratio variations
The mixing in rapid combustion zone is not aided by ___________
local turbulence
diffusion of the gas species
supersonic compression waves
vaporization of the liquid propellants
