The main subjects are to introduce a new correlation for long orifices with radiused inlets by conducting computational fluid dynamics simulation under complex working conditions

and then

analytical model of long orifices with radiused inlets was developed based on fluid network method

and the model was verified by commercial CFD tool Simerics.It is shown that the model has high precision

it is applicable under complex conditions

and only geometric features are required for one-dimensional modeling.Thus it can be used as a standard model in secondary air system simulation widely.