Vortex-generators (VGs) are widely used for flow control on aircrafts, however, its mechanism is not perfectly understood yet because of the complexity of flow with interactions between vortex and turbulent boundary layer. Large eddy simulation (LES) can be a suitable tool to analyze the such complex dynamics, however, the detailed CFD analysis with VG created by computational grid directly requires much time and effort. Thus, the VGs modeling method, such as the BAY-model, is appropriate to calculate with low computational costs. In this paper, we compare between the VG of body-fitted grid and BAY-model, and assess the performance and properties of this model. We evaluate the two errors of the BAY-model, those are modeling error and grid induced error, separately. The results show that the modeling error is very small and it can be ignored to simulate a longitudinal vortex. However, it was observed that the difference of the grid selecting method influences the performance of the BAY-model on Cartesian grids.