Hello, I am an engineer and we used to collect flow rate (X) and Discharge Pressure (Y)from the pump while doing a performance test. We varies pressure and records flow rate to plot a pump curve. The unit is also supplied with a duty point which suggests that the pump should perform a specific flow rate (X) at a desired pressure (Y). When we plot the pump curve in Microsoft excel and add a trend line, the polynomial of 5th order fits well with the curve. The Microsoft excel also show the equation of this polynomial curve as a function of X.
However to find out the deviation we must exactly know how much flow rate (X) will this pump deliver at the desired pressure (Y) while using the polynomial curve. This means we must have an equation as a function of Y.
The questions which I need to ask,
1. If this is the correct method of measuring the deviation of a pump performance from its design requirements ?
2. How can we convert a 5th degree equation from a function of X to function of Y?
3. Is there any software available who could solve it for me?

Regards,

Fazal
[email protected]