The turbulence model developed by Lam and Bremhorst with low values of Reynolds numbers is used to simulate a flow between two impermeable plate walls. This model, corrected by Yap, is able to simulate flow inside the boundary layer on the part of porous walls submitted to the blowing. This model of flow inside a channel with local blowing is coupled with a model of transfers through the impermeable walls and the porous wall, and with the environment. The global model is validated by comparison between experimental results from the literature and those obtained by the authors from experiences carried out with the test facilities of a subsonic thermal wind tunnel. A simulation of non-isothermal flow inside a channel with local blowing shows the attractive way of wall cooling by blowing. The optimal injection ratio is found equal to 0.01.