Narrow Results

We derive an expression for radial distribution function (RDF)-based open boundary forcing for molecules with multiple interaction sites. Due to the high-dimensionality of the molecule configuration space and missing rotational invariance, a computationally cheap, 1D approximation of the arising integral expressions as in the single-centered case is not possible anymore. We propose a simple, yet accurate model invoking standard molecule- and site-based RDFs to approximate the respective integral equation. The new open boundary force model is validated for ethane in different scenarios and shows very good agreement with data from periodic simulations.

Connected vehicles (CVs) have led to innovative changes in the transportation field. In this wise, an extended CA model was established incorporating the CVs and regular vehicles to investigate a roundabout traffic flow under the open boundary condition. The throughput and the phase diagrams of the system in the (${\alpha }_1,{\alpha }_2$) area is constructed in both cases: with and without CVs. The density profile and the capacity are also calculated. The simulation findings show that CVs presentation changes the traffic dynamics, enhancing roundabout capacity in accordance with the CVs penetration rate. Furthermore, it is found that roundabout size plays a dominant role in its performance where it suggests that the midsized roundabouts operate more optimally. Another relevant aspect is the short sized of Splitter Island shows a better performance. Moreover, the traffic dynamics is negatively (resp. positively) correlated to the probability of displaying indicator $P_{\mathrm{\text{ind}}}$ as well as the probability of aggressive driving behavior of regular vehicles (resp. the cooperation probability $P_{\mathrm{\text{cop}}}$).

The two-dimensional shallow water equations were formulated and numerically solved in an arbitrary curvilinear coordinate system, which offers a relatively high degree of flexibility in representing the natural flow domains with structured meshes. The model employs an efficient TVD-MacCormack scheme, which has second-order accuracy in both time and space. Refinements were made to enhance the model's accuracy and stability in computing the shallow wave dynamics in real-world scenarios, with irregular boundaries and uneven beds. In particular, advanced open boundary conditions have been proposed according to the method of characteristics, and rigorous mass conservation has been enforced during the computation at both the inner-domain and the boundaries. These refinements are necessary when modeling the flood inundation over a large area and the tidal oscillation in a macro-tidal estuary. The effectiveness of the refinements was verified by simulating the forced tidal resonance in an idealized condition and the Malpasset dam-break flood in the Reyran river valley. The application of the refined model in the study of tidal oscillations in the Severn Estuary and Bristol Channel can be found in the companion paper.