What can be done to the turbine of Problem 8.5 to achieve 81 percent isolation if the same mount

step 1 A steam power plant has high pressure as 20 megapascal and low pressure as 10 kilo pascal and an

What can be done to the turbine of Problem 8.5 to achieve 81...

Key Concepts

Vibration Isolation

This concept involves reducing the amount of vibrational energy that is transmitted from a source to a structure by using mounting systems or isolators. The goal is to decrease the coupling between the excitation (in this case, the turbine vibrations) and the system that needs to be protected by shifting or tuning the system’s response away from the excitation frequencies.

Natural Frequency Tuning

Adjusting the natural frequency of a system is critical in achieving effective vibration isolation. By altering the system’s mass or stiffness, the natural frequency can be modified so that it is significantly lower than the excitation frequency, which minimizes the transmission of vibration energy. This tuning is essential when using the same isolator and reaching a specific isolation target, such as 81 percent.

Mass Modification

Increasing the effective mass of the vibrating component (here, the turbine) is a common method to lower its natural frequency without changing the isolator’s properties. This change in inertia alters the dynamic response of the turbine, helping to achieve a more favorable frequency ratio between the excitation and the system’s natural frequency, which in turn improves isolation performance.

Frequency Ratio

The ratio between the excitation frequency and the system's natural frequency plays a crucial role in the effectiveness of vibration isolation. A larger frequency ratio typically results in reduced force transmission to the system. Achieving a target isolation percentage, like 81 percent, often requires ensuring that the natural frequency of the turbine system is sufficiently lower than the frequencies of the excitation, a parameter that can be adjusted through mass modification or stiffness changes.

Transcript

Please give Ace some feedback