Applications of Compressible Flow: Online Learning Quizzes

Question 1

In a gas turbine engine, what is the main purpose of the compressor?

Accepted Answer

Increase air pressure and temperature before combustion

Answer

Generate thrust by expanding hot gases

Answer

Mix fuel and air for combustion

Answer

Provide cooling air for engine components

Question 2

In a gas turbine engine, which component converts thermal energy into mechanical energy?

Accepted Answer

Turbine

Answer

Compressor

Answer

Combustor

Answer

Nozzle

Question 3

In designing a nozzle for a supersonic jet engine, which factor is of paramount importance?

Accepted Answer

Area ratio

Answer

Pressure ratio

Answer

Material strength

Answer

Weight

Question 4

Which of the following is NOT a type of discontinuity wave in compressible flow?

Accepted Answer

Expansion fan

Answer

Normal shock wave

Answer

Oblique shock wave

Answer

Contact discontinuity

Question 5

The isentropic relations for compressible flow assume:

Accepted Answer

Adiabatic and reversible flow

Answer

Adiabatic and irreversible flow

Answer

Isothermal and reversible flow

Answer

Isothermal and irreversible flow

Question 6

Which component is crucial for efficient thrust generation in jet engines?

Accepted Answer

Nozzle

Answer

Compressor

Answer

Combustor

Answer

Turbine

Question 7

The primary function of a rocket nozzle is to:

Accepted Answer

Increase flow velocity and generate thrust

Answer

Reduce flow temperature and improve efficiency

Answer

Control the direction of exhaust gases

Answer

Separate fuel and oxidizer

Question 8

Mach number relates to flow speed in compressible flows as:

Accepted Answer

Mach number is directly proportional to flow speed

Answer

Mach number is inversely proportional to flow speed

Answer

Mach number is equal to flow speed

Answer

Mach number is independent of flow speed

Question 9

In a gas turbine, the main function of the compressor is to:

Accepted Answer

Increase the pressure of the incoming air

Answer

Reduce the temperature of the incoming air

Answer

Increase the velocity of the incoming air

Answer

Decrease the density of the incoming air

Question 10

The fundamental principle behind the operation of a jet engine is:

Accepted Answer

Newton's third law of motion

Answer

Newton's first law of motion

Answer

Conservation of mass

Answer

Conservation of energy

Question 11

Which of the following is not a characteristic of supersonic flow?

Accepted Answer

Subsonic flow velocity

Answer

Formation of shock waves

Answer

Increase in pressure and temperature

Answer

Decrease in density

Question 12

The Mach number represents the ratio of:

Accepted Answer

Flow velocity to the speed of sound

Answer

Pressure to density

Answer

Temperature to velocity

Answer

Density to viscosity

Question 13

The Prandtl-Meyer expansion fan is used to describe:

Accepted Answer

Supersonic flow around a sharp corner

Answer

Subsonic flow around a blunt body

Answer

Transonic flow through a nozzle

Answer

Hypersonic flow over a wing

Question 14

In a gas turbine, the isentropic efficiency of the compressor is defined as the ratio of:

Accepted Answer

Actual work done by the compressor to the theoretical work required for the same pressure ratio

Answer

Actual temperature ratio to the theoretical temperature ratio

Answer

Actual pressure ratio to the theoretical pressure ratio

Question 15

In a supersonic nozzle, the flow velocity at the exit is:

Accepted Answer

Greater than the local speed of sound

Answer

Equal to the local speed of sound

Answer

Less than the local speed of sound

Question 16

The thrust generated by a jet engine is primarily due to:

Accepted Answer

Momentum change of the exhaust gases

Answer

Heat transfer from the engine to the surrounding air

Answer

Gravitational force acting on the engine

Answer

Pressure difference between the inlet and exit that is greater than atmospheric pressure

Question 17

The specific impulse of a rocket is:

Accepted Answer

Force produced per unit mass flow rate of propellant

Answer

Mass of the rocket divided by its thrust

Answer

Time it takes for the rocket to reach a certain altitude

Question 18

The Mach number is defined as the ratio of:

Accepted Answer

Flow velocity to the local speed of sound

Answer

Flow pressure to the stagnation pressure

Answer

Flow density to the stagnation density

Answer

Flow temperature to the stagnation temperature

Question 19

The Prandtl-Meyer expansion fan is associated with:

Accepted Answer

Supersonic flow turning

Answer

Normal shock formation

Answer

Subsonic flow turning

Answer

Boundary layer separation

Question 20

The critical pressure ratio for a convergent nozzle is the pressure ratio at which:

Accepted Answer

The flow becomes choked (sonic at the exit)

Answer

The flow becomes supersonic

Answer

The mass flow rate reaches its maximum value

Answer

The shock wave forms in the nozzle

Question 21

The Reynolds number is a dimensionless parameter used to characterize:

Accepted Answer

Flow regime and viscous effects

Answer

Heat transfer rates

Answer

Compressibility effects

Answer

Propulsion efficiency

Question 22

The Fanno flow is a one-dimensional, adiabatic, and frictionless flow in:

Accepted Answer

Constant area ducts

Answer

Diffusers

Answer

Convergent nozzles

Answer

Shock waves