The whole turbulent flow field around a two-dimensional aerofoil is solved with a consistent numerical method on a single-grid system and with an intermittency implemented two-equation model, namely the k-epsilon-gamma turbulence model in elliptic form. In order to solve the numerical instability problem arising from the branch-cut in C-type grids using the non-staggered finite-volume method, a new numerical technique is proposed to guarantee the correct velocity-pressure coupling along the branch-cut. The computational results are compared with those by the standard k-epsilon model and experimental data. This study demonstrates the relative simplicity of the present C-type single grid system, and the capability is assessed of the k-epsilon-gamma equations for predicting turbulent flows consisting of both wall-free and wall-bounded regions.