The Cebeci–Smith model, developed by Tuncer Cebeci and Apollo M. O. Smith in 1967, is a 0-equation eddy viscosity model used in computational fluid dynamics analysis of turbulenceinboundary layer flows. The model gives eddy viscosity, , as a function of the local boundary layer velocity profile. The model is suitable for high-speed flows with thin attached boundary layers, typically present in aerospace applications. Like the Baldwin-Lomax model, it is not suitable for large regions of flow separation and significant curvature or rotation. Unlike the Baldwin-Lomax model, this model requires the determination of a boundary layer edge.
In a two-layer model, the boundary layer is considered to comprise two layers: inner (close to the surface) and outer. The eddy viscosity is calculated separately for each layer and combined using:
where is the smallest distance from the surface where is equal to .
The inner-region eddy viscosity is given by:
where
with the von Karman constant usually being taken as 0.4, and with
The eddy viscosity in the outer region is given by:
where , is the displacement thickness, given by
and FK is the Klebanoff intermittency function given by