Fully atomistic molecular dynamics simulations of the mechanism of the drag reduction agent

Drag reduction mechanism of alpha olefin in crude oil had been investigated in study. Molecular dynamics simulations and quantum chemistry calculation at molecular level based on density functional theory were carried out. By investigation to molecule aggregation, and by comparison of the shear behavior adding DRA and without it, it included the influences of carbon number, shear rate and branch carbon number. It could be concluded that short-chain molecules are easier to enter into the absorbed films near the pipeline wall than long-chain molecules. The shearing speed has a less influence on the distributions of alkenes in the pipeline. While, with the branched chain increase, the number of DRA molecules entering into absorbed layer near the wall increases else. But the adsorption of crude oil on the pipeline wall is decreased. Since DRA molecules diffuse toward absorbed layers, so it can effectively reduce the drag in crude oil transport and overcome the energy lost in the pipeline.