A method for modeling the effect of turbulence on the cut point function of a decanting centrifuge includes inputting data related to the centrifuge including the bowl radius, r.sub.2, the pond top radius, r.sub.1, the bowl length, L.sub.B, the angular velocity, .omega., of the centrifuge into an analyzer, measuring data related to the feed fluid including a fluid density, .rho..sub.f, a particle density .rho..sub.s, a fluid viscosity, .mu., and the flow rate, Q, and inputting the measured data into the analyzer, calculating a d.sub.100 cut point as a function of the flow rate, modeling a first cut functions for laminar flow as a function of a particle diameter, d.sub.i, using the calculated d.sub.100 cut point function, calculating a maximum point within the pond, I.sub.b, I.sub.p, at which a particle having particle diameter, d.sub.i, must reach a laminar boundary layer within the pond to be captured within the bowl, wherein I.sub.b is defined as the distance from the inlet at which the particle having particle diameter, d.sub.i encounters the laminar boundary layer and I.sub.p is defined as the height of the boundary layer above a bottom of the pond and modeling a second cut function for turbulent flow having a laminar boundary layer along the bowl inner surface as a function of particle diameter, d.sub.i. A turbulence factor is used to model the second cut function and may be used to predict a corrected cut point as a function of particle diameter.