Integration of rotational algorithms into dissipative particle dynamics: modeling polyaromatic hydrocarbons on the meso-scale

The aggregation and diffusion of asphaltenes studied by GPU-accelerated dissipative particle dynamics

“…Fig. 6 shows the MSD of each fraction of heavy crude oil, which also agree well with that in Zhang's work [18]. The slop of the MSD curve for each fraction can reflect the diffusivity.…”

“…In addition, some larger aggregates consist of more than one nanoaggregate, which can be identified as clusters. From this figure, the features of aggregate structure in heavy oil that our simulation presented are similar to that in Zhang's work [17,18]. Fig.…”

“…Zhang et al have integrated three rigid body rotational algorithms into the standard DPD program, including the Kim method [27], the Euler method and the quaternion method [18]. The superiority of the quaternion method was confirmed after the simulation tests.…”

“…In order to validate our implementation, simulations of the heavy crude oil system were performed and the simulation results were compared with that in Zhang's work [17,18]. A 120 * 120 * 120 system was used, the mass ratio of five fractions of heavy crude oil (asphaltenes:resins:aromatic:saturate:light fractions) is 1:3:3:2:17.…”

“…Aguilera-Mercado et al [16] performed canonical MC simulations on crude oils system by treating asphaltenes as discotic seven-center LennardJonesium molecules and resins as single spheres, and found that asphaltenes exhibit a complex multimodal aggregation pattern. Considering the temporal and spatial limitations of MD and the oversimplification of the structural features of asphaltenes and resins in MC, Zhang et al [17,18] developed a modified DPD program to study the aggregate structure in heavy crude oil. In their work, the quaternion method [19] was integrated into the standard DPD, and model molecules for each fraction in heavy crude oil were determined.…”