Calculating Shaft Natural Frequency in Free Air and Liquid

[Christoffer28]

Hello Fellow members.

In many litterature about mixing liquids in tanks, they describe how to calculate the natural frequency of shafts in free air.
But i have only found one book that describe about natural frequency of shafts in liquid, and it should have a damping effect of the natural frequency.

The question is: What is the best method? to calculate the frequency in free air or in liquid?Thanks in advance.
Christoffer

 

[Baluncore]

Welcome to PF.

What is the best method? to calculate the frequency in free air or in liquid?

If the mixer shaft might be operated, even only once, while there is no, or low, liquid in the tank, then it must be calculated for air.

 

[Christoffer28]

Ok, so its a question of dimensioning a worst case scenario.

Thanks for the answer :)