When the same pump operates at 3000 rpm and 3100 rpm, is its specific speed the same?
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The same pump is used for selection, but with different rotational speeds. Are the specific speed and NPSH specific speed still constant? Or do they change according to the laws of similarity?
It’s fixed; I calculated it again, and based on the similarity laws and the cavitation similarity law, the coefficient that results after division is still 1.
This post was last edited by 3983596_FPPZ on 2019-1-10 at 13:29. Additional question: Are the specific speed and net specific speed the same before and after cutting the impeller? (Theoretically)
The same applies; the prerequisite is that it relates to the impeller with the maximum diameter, which is an inherent characteristic of the pump itself
The value remains constant; the conditions impose limits – the maximum impeller size, the flow rate at the optimal efficiency point, and the specified rotation speed