🔍 Key Concepts

• Steam turbine nozzles as devices that expand steam and increase its velocity • Difference between subsonic and supersonic flow in nozzles • How nozzle shape (convergent / divergent / convergent-divergent) affects pressure and velocity

💭 Think About

• When steam passes through a turbine nozzle, what happens to its pressure, temperature, and velocity? Which nozzle shape best supports that change over a wide pressure drop? • Which nozzle shape is typically used when you need to accelerate a fluid to very high (even supersonic) velocities from high-pressure steam? • Thinking about basic fluid flow: in subsonic flow, what does a convergent passage do to velocity and pressure, and what extra feature is needed if you want to go beyond that regime?

✅ Before You Answer

• Be clear whether turbine nozzles handle large pressure drops and high expansion ratios, not just small ones • Match the nozzle geometry (convergent, divergent, or both) with the intended velocity increase and pressure decrease • Eliminate any option that is mainly associated with changing direction only (deflection) rather than true pressure-to-velocity energy conversion