Han Li¹, Tianding Chen^{2, *}, Hualiang Teng³, Yingtao Jiang⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.2, pp. 253-274, 2019, DOI:10.31614/cmes.2019.05807

Abstract In any classical value-based reinforcement learning method, an agent, despite of its continuous interactions with the environment, is yet unable to quickly generate a complete and independent description of the entire environment, leaving the learning method to struggle with a difficult dilemma of choosing between the two tasks, namely exploration and exploitation. This problem becomes more pronounced when the agent has to deal with a dynamic environment, of which the configuration and/or parameters are constantly changing. In this paper, this problem is approached by first mapping a reinforcement learning scheme to a directed graph, and… More >

Dugang Guo^{1, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 419-430, 2019, DOI:10.32604/fdmp.2019.07831

Abstract The role of different grid search computer algorithms for the determination of the thermodynamic properties of water and steam in the p-T and P-S planes has been investigated via experimental and analytical methods. The results show that the spline interpolation grid search algorithm and the power grid search algorithm are more efficient, stable and clear than other algorithms. More >

Donghong He¹, Hang Ma^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 15-40, 2019, DOI:10.31614/cmes.2019.04327

Abstract To deal with the problems encountered in the large scale numerical simulation of three dimensional (3D) elastic solids with fluid-filled pores, a novel computational model with the corresponding iterative solution procedure is developed, by introducing Eshelby’s idea of eigenstrain and equivalent inclusion into the boundary integral equations (BIE). Moreover, by partitioning all the fluid-filled pores in the computing domain into the near- and the far-field groups according to the distances to the current pore and constructing the local Eshelby matrix over the near-field group, the convergence of iterative procedure is guaranteed so that the problem… More >

Haojie Pan^{1, *}, Xiaojun Zhou¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 403-417, 2019, DOI:10.32604/fdmp.2019.07808

Abstract Traditional mathematical models cannot predict and explain the phenomenon by which the drag torque (DT) in wet clutches rises in the high-speed zone. In order to evaluate the DT in such conditions, a two-phase air-fluid mathematical model for a DT with grooves was elaborated. The mathematical model was based on the theory of viscous fluid flow. A two-phase volume of fluid model was also used to investigate the distribution and volume fraction of air and fluid. Experiments on three friction plates with different grooves were conducted to validate the resulting mathematical model. It was found More >

Kazuhiko Kakuda^1,*, Tomoyuki Enomoto¹, Shinichiro Miura²

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 1-14, 2019, DOI:10.31614/cmes.2019.04676

Abstract The nonlinear activation functions in the deep CNN (Convolutional Neural Network) based on fluid dynamics are presented. We propose two types of activation functions by applying the so-called parametric softsign to the negative region. We use significantly the well-known TensorFlow as the deep learning framework. The CNN architecture consists of three convolutional layers with the max-pooling and one fully-connected softmax layer. The CNN approaches are applied to three benchmark datasets, namely, MNIST, CIFAR-10, and CIFAR-100. Numerical results demonstrate the workability and the validity of the present approach through comparison with other numerical performances. More >

Caizhe Hao¹, Xiaoming Song^{1, *}, Zhining Jia¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 391-401, 2019, DOI:10.32604/fdmp.2019.07771

Abstract In order to analyze the influence of the hole chamfer on the metering performances of a Multi-hole Orifice Flowmeter and optimize the related orifice structure, a multi-hole orifice flowmeter with DN80 and throttle ratio of 0.45 was considered in the present study. The flow field characteristics were determined in the framework of a CFD technique. The results show that the multi-hole orifice flowmeter with filleting transition around the throttle orifice has higher accuracy in a wide range of the space of parameters, and is more suitable for accurate measurement of fluid in process control. More >

Pengxiao Chen¹, Kai Huang^{1, 2}, Fenghe Wang¹, Weijun Xie¹, Shuo Wei¹, Deyong Yang^{1, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 367-389, 2019, DOI:10.32604/fdmp.2019.07762

Abstract The so-called pore network model has great advantages in describing the process of heat and mass transfer in porous media. In order to construct a random two-dimensional (2D) irregular pore network model for an unconsolidated material, image processing technology was used to extract the required topological and geometric information from a 2D sample of soybean particles, and a dedicated algorithm was elaborated to merge some adjacent small pores. Based on the extracted information, a 2D pore network model including particle information was reconstructed and verified to reflect the pore structure of discrete particles. This More >

Zhiyuan Cheng^{1, 2, *}, Yulan Wang¹, Yingang Wang², Qiong Nie²

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 357-366, 2019, DOI:10.32604/fdmp.2019.07843

Abstract On the basis of harmonic mapping theory, a mobile grid technology is applied to computational fluid dynamics (CFD). Starting from the observation that standard fixed-grid techniques often fail in addressing problems with large deformations, we elaborate a new algorithm relying on the software COMSOL Multiphysics 5.3a to solve the coupling of the mobile grid equation and the governing differential equations for fluid flow. The motion of water in a water tank when the tank waggles is simulated. We demonstrate that this technology can be implemented without a significant increase in the computational cost with respect More >

Chaoyi Wan^{1, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 343-356, 2019, DOI:10.32604/fdmp.2019.07812

Abstract A comparative numerical study has been conducted on the thermal performance of a heat pipe cooling system considering several influential factors such as the coolant flow rate, the coolant inlet temperature, and the input power. A comparison between numerical data and results available in the literature has demonstrated that our numerical procedure could successfully predict the heat transfer performance of the considered heat pipe cooling system for a battery. Specific indicators such as temperature, heat flux, and pressure loss were extracted to describe the characteristics of such a system. On the basis of the distributions More >

Yanxu Guo¹, Peng Zhao², Qingsong Zhang¹, Rentai Liu^1,*, Lianzhen Zhang³, Yankai Liu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.4, pp. 321-342, 2019, DOI:10.32604/fdmp.2019.07844

Abstract To study the penetration mechanism of cement-based slurry in intersected fractures during grouting and the related pressure distribution, we have used two different variants of cement, namely, basic cement slurry and fast-setting cement slurry. The influence of a retarder, time-varying viscosity, fracture width and location of injection hole is also considered. A finite element software is used to implement two and three-dimensional numerical models for grouting of intersected fractures in hydrostatic conditions. Results show that there are significant differences in the diffusion morphology and pressure distribution depending on the considered cement slurry. Retarder can More >