Principles of Steam Flow through Nozzles — Lesson 5

This lesson covers the principles of steam flow through nozzles, a concept crucial for power generation and steam turbines. It delves into the historical context, explaining how Delawal used a convergent diversion nozzle in 1888 to accelerate steam for impulse steam turbines. The lesson further discusses the importance of studying steam flow due to its extensive use in power generation. It also explains the calorically perfect model and its assumptions, and why these assumptions are invalid for steam. The lesson concludes with the concept of isentropic expansion of steam and the conditions for maximum mass flow rate.

Video Highlights

01:45 - Explanation of the calorically perfect assumption
07:07 - Explanation of isentropic expansion of steam
10:12 - Explanation of the energy equation for steam expansion
14:53 - Explanation of the conditions for maximum velocity in steam expansion

Key Takeaways

- The study of steam flow through nozzles is crucial due to its extensive use in power generation.
- The theory of choking of a nozzle, area mach number relationship, and mass flow rate of choke flow in the nozzle are applicable to steam and refrigerant.
- The isentropic expansion of steam can be written as p v raised to n equal to constant.
- The concept of choking can be demonstrated in an alternative manner by constantly lowering the exit pressure to reach a maximum mass flow rate.