How to Fill as Quadratic

Filters and screens impose a pressure drop that varies with flow rate. The variation is non-linear, but manufacturers will often provide only one data point for pressure loss at the design flow rate. Using a single point, or constant pressure drop, can produce significant inaccuracies in your model. With this in mind, AFT offers the “Fill As Quadratic” option for entering loss data.

Using only a single point, “Fill As Quadratic” will create two additional points for you. This first is simply 0,0; zero flow produces zero pressure drop. The second point is 2 x Flow and 4 x Pressure Drop. A curve is then fit through all three points and there you have it; a quadratic loss profile from only one data point. By using values along the curve, more realistic losses can be modeled for a wide range of flow rates.

The Fill As Quadratic feature is available in AFT Fathom, AFT Arrow, and AFT Impulse.