When pork carcasses are transported in a refrigerated trailer, all of them should be correctly ventilated. CFD simulations were performed to assess the homogeneity of air circulation around the carcasses. From an Xray scanner of a carcass, a simplified geometry was deduced. The air volume inside a semitrailer containing 430 pork half-carcasses was then meshed (21.10 6 cells). The Reynolds Averaged Navier Stokes equations were solved with the k-ε turbulence model. The flow pattern is very complex: air is blown at high velocity on the top of the container front, forming a wall jet. There is an air entrainment by this jet whose section increases whereas its velocity decreases. Part of the blown air flows throughout the 'porous' zone constituted by the carcasses while another part reaches the gap between the carcasses and the doors at the rear of the container. Finally air flows back toward the outlet. Zones of low velocity between half-carcasses were identified.