Steam Flow Quiz

What is the primary function of a convergent-divergent nozzle in steam flow applications?

• To reduce the velocity of steam

• To increase the pressure of steam

• To accelerate steam to supersonic velocities

• To maintain constant temperature of steam

The critical pressure ratio for steam flow through nozzles is defined as:

• The ratio of inlet pressure to exit pressure at which sonic velocity occurs at the throat

• The ratio of exit pressure to inlet pressure at which sonic velocity occurs at the throat

• The ratio of throat pressure to inlet pressure at which sonic velocity occurs at the throat

• The ratio of inlet pressure to throat pressure at which sonic velocity occurs at the throat

For steam with a specific heat ratio (γ) of 1.3, the critical pressure ratio is approximately:

• 0.546

• 0.454

• 0.577

• 0.633

When the actual pressure ratio exceeds the critical pressure ratio in a steam nozzle:

• The flow becomes choked and the mass flow rate cannot increase further

• The nozzle efficiency increases significantly

• The steam temperature increases at the exit

• Condensation occurs immediately

In a convergent-divergent nozzle, the divergent section is designed to:

• Reduce the steam velocity to subsonic

• Further accelerate the steam to supersonic velocities

• Maintain constant velocity

• Increase the pressure of steam

The effect of friction in steam nozzles results in:

• Higher exit velocity and lower mass flow rate

• Lower exit velocity and higher mass flow rate

• Lower exit velocity and lower mass flow rate

• Higher exit velocity and higher mass flow rate

Supersaturated flow in steam nozzles occurs when:

• Steam expands so rapidly that condensation cannot occur despite crossing the saturation line

• Steam temperature increases beyond saturation temperature

• Steam pressure exceeds the critical pressure

• Steam velocity reaches twice the speed of sound

The Wilson line in steam nozzle flow represents:

• The point where friction effects become dominant

• The boundary between subsonic and supersonic flow

• The locus of points where spontaneous condensation begins in supersaturated steam

• The condition of maximum mass flow rate

In an impulse turbine, as steam passes through the moving blades:

• Pressure remains constant while velocity decreases

• Both pressure and velocity decrease

• Pressure increases while velocity decreases

• Both pressure and velocity increase

The main characteristic of a reaction turbine is:

• Pressure drop occurs only in the fixed blades

• Pressure drop occurs in both fixed and moving blades

• No pressure drop occurs in either blade row

• Velocity remains constant throughout the stage