Accelerating Reactive Transport Modeling: On-Demand Machine Learning Algorithm for Chemical Equilibrium Calculations

Transport in Porous Media - During reactive transport modeling, the computing cost associated with chemical equilibrium calculations can be 10 to 10,000 times higher than that of fluid flow, heat...     

Multiblock Pore-Scale Modeling and Upscaling of Reactive Transport: Application to Carbon Sequestration

In order to safely store CO₂ in depleted reservoirs and deep saline aquifers, a better understanding of the storage mechanisms of CO₂ is needed. Reaction of CO₂ with minerals to form precipitate in the subsurface helps to securely store CO₂ over geologic time periods, but a concern is the formation of localized channels through which CO₂ could travel at large, localized rates. Pore-scale network modeling is an attractive option for modeling and understanding this inherently pore-level process, but the relatively small domains of pore-scale network models may prevent accurate upscaling. Here, we develop a transient, single-phase, reactive pore-network model that includes reduction of throat conductivity as a result of precipitation. The novelty of this study is the implementation of a new mortar/transport method for coupling pore networks together at model interfaces that ensure continuity of pressures, species concentrations, and fluxes. The coupling allows for modeling at larger scales which may lead to more accurate upscaling approaches. Here, we couple pore-scale models with large variation in permeability and porosity which result in initial preferential pathways for flow. Our simulation results suggest that the preferential pathways close due to precipitation, but are not redirected at late times.     

On the Convergence to Equilibrium for Degenerate Transport Problems

We give a counterexample which shows that the asymptotic rate of convergence to the equilibrium state for the transport equation, with a degenerate cross section and in the periodic setting, cannot be better than t ^?1/2 in the general case. We suggest, moreover, that the geometrical properties of the cross section are the key feature of the problem and impose, through the distribution of the forward exit time, the speed of convergence to the stationary state.     

Correction to: Relating Darcy-Scale Chemical Reaction Order to Pore-Scale Spatial Heterogeneity

Transport in Porous Media -     

有限变形下多晶晶体塑性模型算法及应用

用Sanna和Zacharia^[1]所提出的延性单晶本构模型的积分算法和Taylor多晶模型假设研究了时间步长和硬化模型的选取对多晶集合体的应力应变响应和织构演化的影响。该算法是利用变形梯度乘法分解获得弹性变形梯度演化方程，用增量迭代法积分该方程，显式更新各滑移上的临界分切剪应力。算例的结果表明该算法具有时间步大，计算效率高的特点，另外，不同硬化模型的选取对多晶集合体应力应变响应的预测有明显的影响但对织构演化的预测影响不大。     

Stochastic 3D Modeling of Three-Phase Microstructures for Predicting Transport Properties: A Case Study

Transport in Porous Media - We compare two conceptually different stochastic microstructure models, i.e., a graph-based model and a pluri-Gaussian model, that have been introduced to model the...     

Correction to: Fast data-driven model reduction for nonlinear dynamical systems

Nonlinear Dynamics -     

Correction to: Two-Dimensional Culture Systems to Enable Mechanics-Based Assays for Stem Cell-Derived Cardiomyocytes

Experimental Mechanics - The authors would like to correct the sentence “The mass ratio……” in the subsection on Engineered Substrate System in MATERIALS AND METHODS, to read:     

Correction to: Practical framework for data-driven RANS modeling with data augmentation

Acta Mechanica Sinica -     

Correction to: Numerical simulation for two-dimensional variable-order fractional nonlinear cable equation

Nonlinear Dynamics - This corrigendum corrects equation (2.2) from the original paper. This error does not change the results, figures, discussions and main conclusions of the paper.     

Maximum and Minimum Principles for Radionuclide Transport Calculations in Geological Radioactive Waste Repository: Comparison Between a Mixed Hybrid Finite Element Method and Finite Volume Element discretizations

In the context of high-level radioactive waste repository simulations, specific waste repository system properties require the use of a highly heterogeneous and anisotropic diffusion tensors. Classical finite volume or mixed hybrid finite element schemes produce non-physical negative concentrations and therefore are unsuitable for simulations which couple transport and chemical reactivity models. In this article, the authors use a new finite volume scheme satisfying a minimum and maximum principle to solve the transport equations and demonstrate that this scheme avoids the negative concentration values generated by other schemes.     

Correction to: A Two-Parametric Model for Gas Flow in Low-Permeable Porous Materials

Transport in Porous Media - The original publication of the article includes the error in Fig. 9 legend.     

Correction to: Frequency domain approach for probabilistic flutter analysis using stochastic finite elements

Meccanica - This article was published with a wrong author affiliation. Please find in this document the correct affiliations that should be regarded as final by the reader.     

Correction to: Adaptive RBFNN finite-time control of normal forms for underactuated mechanical systems

Nonlinear Dynamics - The list of authors in the original publication was incomplete. The complete list of authors is shown here, including the third author, Faiçal Mnif.