The boundaries between the discrete combustion zones inside the combustion chamber is not ________

irregular

immovable

undulating

local variations

Correct Answer : immovable

Explanation : The boundaries are not immovable. They are dynamically movable and subject to variations in temperature, locally intense radiation emissions etc.

Recently Updated in Rocket Propulsion Questions

Which of the following combustion instabilities happen due to propellant flow rate disturbances?

Pogo

Screaming

Screeching

Entropy waves

Correct Answer : Option (A) : Pogo

Explanation : Pogo instability is a longitudinal instability due to propellant flow rate disturbances. They are low-frequency waves, usually lying in the 10-50 Hz frequency zone.

Which of the following combustion instabilities occur due to propellant pump cavitation?

Pogo

Buzzing

Chugging

Screaming

Correct Answer : Option (C) : Chugging

Explanation : Chugging can occur in test facilities due to the propellant pump cavitation. It can also happen due to gas entrapment in propellant flow or due to tank pressurization control fluctuations.

high-frequency combustion instability is called ________

buzzing

chugging

entropy waves

squealing

Correct Answer : Option (D) : squealing

Explanation : Squealing is the term used to denote combustion instabilities with high-frequency of occurrence of fairly large concentrations of vibratory energy. The frequency range lies above 1000 Hz. It is also called screaming.