Introduction:
The Curtis turbine is a type of steam turbine used to convert the thermal energy of steam into mechanical work. It is an example of a velocity compounded impulse steam turbine. Let's explore this in more detail.

Explanation:
Impulse Steam Turbine:
An impulse steam turbine operates on the principle of Newton's second law of motion. It consists of a set of stationary nozzles and a set of moving blades. The steam is expanded in the nozzles, and the high-velocity jets of steam strike the moving blades, causing them to rotate. The steam's kinetic energy is converted into the rotational motion of the blades, producing mechanical work.

Velocity Compounded:
In a velocity compounded impulse steam turbine, the steam is expanded in multiple stages. Each stage consists of a set of nozzles and blades. The steam is first expanded in the high-pressure nozzles and strikes the high-pressure blades, causing them to rotate. The steam then enters the low-pressure nozzles and strikes the low-pressure blades, further increasing the rotational speed. This compound expansion helps to extract more energy from the steam and increase the overall efficiency of the turbine.

Curtis Turbine:
The Curtis turbine is a specific design of a velocity compounded impulse steam turbine. It was developed by Charles Curtis in the early 1900s. The Curtis turbine consists of a series of alternating rows of fixed nozzles and moving blades. The high-pressure steam is expanded in the nozzles and strikes the blades, causing them to rotate. The steam then enters the next set of nozzles and blades, further increasing the rotational speed. This process is repeated in multiple stages until the steam is fully expanded.

Advantages of Curtis Turbine:
- Higher Efficiency: The velocity compounded design allows for better energy extraction from the steam, resulting in higher turbine efficiency.
- Compact Size: The Curtis turbine is more compact compared to other types of steam turbines, making it suitable for applications with limited space.
- Flexibility: The Curtis turbine can handle a wide range of steam conditions and is suitable for both small and large power generation applications.

Conclusion:
The Curtis turbine is an example of a velocity compounded impulse steam turbine. Its design allows for efficient energy extraction from the steam and offers advantages such as higher efficiency, compact size, and flexibility.