Abstract: A simplified adaptive mesh method is applied to solve the two-dimensional convection -diffusion model of batching. In this method, the density of the mesh is controlled by the velocity and the concentration gradient, and the traditional fixed grid is replaced by the dynamic mesh. In the two-dimension model, the velocity field and the turbulent diffusion rate is derived based on the mixed length theory，with the consideration of the influence on the mixing oil by its viscosity variation. The goal is to improve the computation precision and reduce the calculation amount to make it suitable for batching simulations in long distance pipelines. The effectiveness of this method is verified by the comparative analysis of the numerical experiment. The numerical analysis shows how the Reynolds number, the product sequence and the transportation distance influence the results.