scholarly journals Development of a novel reconstruction method for two-phase flow CT with improved simulated annealing algorithm

2020 ◽  
Author(s):  
Mingfei Yan ◽  
Huasi Hu ◽  
Guang Hu ◽  
Bin Liu ◽  
Chao He ◽  
...  
Keyword(s):  
Simulated Annealing ◽  
Simulated Annealing Algorithm ◽  
Two Phase Flow ◽  
Reconstruction Method ◽  
Phase Flow ◽  
Two Phase ◽  
Annealing Algorithm

scholarly journals Modeling of Interior Ballistic Gas-Solid Flow Using a Coupled Computational Fluid Dynamics-Discrete Element Method

2013 ◽  
Vol 80 (3) ◽  
Author(s):  
Cheng Cheng ◽  
Xiaobing Zhang
Keyword(s):  
Discrete Element Method ◽  
Gas Phase ◽  
Two Phase Flow ◽  
Discrete Element ◽  
Particle Collision ◽  
Contact Detection ◽  
Reconstruction Method ◽  
Phase Flow ◽  
Two Phase ◽  
Element Method

In conventional models for two-phase reactive flow of interior ballistic, the dynamic collision phenomenon of particles is neglected or empirically simplified. However, the particle collision between particles may play an important role in dilute two-phase flow because the distribution of particles is extremely nonuniform. The collision force may be one of the key factors to influence the particle movement. This paper presents the CFD-DEM approach for simulation of interior ballistic two-phase flow considering the dynamic collision process. The gas phase is treated as a Eulerian continuum and described by a computational fluid dynamic method (CFD). The solid phase is modeled by discrete element method (DEM) using a soft sphere approach for the particle collision dynamic. The model takes into account grain combustion, particle-particle collisions, particle-wall collisions, interphase drag and heat transfer between gas and solid phases. The continuous gas phase equations are discretized in finite volume form and solved by the AUSM+-up scheme with the higher order accurate reconstruction method. Translational and rotational motions of discrete particles are solved by explicit time integrations. The direct mapping contact detection algorithm is used. The multigrid method is applied in the void fraction calculation, the contact detection procedure, and CFD solving procedure. Several verification tests demonstrate the accuracy and reliability of this approach. The simulation of an experimental igniter device in open air shows good agreement between the model and experimental measurements. This paper has implications for improving the ability to capture the complex physics phenomena of two-phase flow during the interior ballistic cycle and to predict dynamic collision phenomena at the individual particle scale.

scholarly journals The Sparsity Adaptive Reconstruction Algorithm Based on Simulated Annealing for Compressed Sensing

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yangyang Li ◽  
Jianping Zhang ◽  
Guiling Sun ◽  
Dongxue Lu
Keyword(s):  
Simulated Annealing ◽  
Simulated Annealing Algorithm ◽  
Matching Pursuit ◽  
Optimal Solution ◽  
Sparse Reconstruction ◽  
Reconstruction Method ◽  
Reconstruction Algorithms ◽  
Adaptive Simulated Annealing ◽  
Annealing Algorithm ◽  
Adaptive Simulated Annealing Algorithm

This paper proposes a novel sparsity adaptive simulated annealing algorithm to solve the issue of sparse recovery. This algorithm combines the advantage of the sparsity adaptive matching pursuit (SAMP) algorithm and the simulated annealing method in global searching for the recovery of the sparse signal. First, we calculate the sparsity and the initial support collection as the initial search points of the proposed optimization algorithm by using the idea of SAMP. Then, we design a two-cycle reconstruction method to find the support sets efficiently and accurately by updating the optimization direction. Finally, we take advantage of the sparsity adaptive simulated annealing algorithm in global optimization to guide the sparse reconstruction. The proposed sparsity adaptive greedy pursuit model has a simple geometric structure, it can get the global optimal solution, and it is better than the greedy algorithm in terms of recovery quality. Our experimental results validate that the proposed algorithm outperforms existing state-of-the-art sparse reconstruction algorithms.

scholarly journals A Simulated Annealing Algorithm for Solving Two-Echelon Vehicle Routing Problem with Locker Facilities

Algorithms ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 218
Author(s):  
A. A. N. Perwira Redi ◽  
Parida Jewpanya ◽  
Adji Candra Kurniawan ◽  
Satria Fadil Persada ◽  
Reny Nadlifatin ◽  
...  
Keyword(s):  
Simulated Annealing ◽  
Vehicle Routing ◽  
Vehicle Routing Problem ◽  
Simulated Annealing Algorithm ◽  
Two Phase ◽  
Routing Problem ◽  
Intermediate Facilities ◽  
Annealing Algorithm ◽  
Phase Optimization ◽  
The Cost

We consider the problem of utilizing the parcel locker network for the logistics solution in the metropolitan area. Two-echelon distribution systems are attractive from an economic standpoint, whereas the product from the depot can be distributed from or to intermediate facilities. In this case, the intermediate facilities are considered as locker facilities present in an accessible location in the vicinity of the final customers. In addition, the utilization of locker facilities can reduce the cost caused by the unattended deliveries. The problem is addressed as an optimization model that formulated into an integer linear programming model denoted as the two-echelon vehicle routing problem with locker facilities (2EVRP-LF). The objective is to minimize the cost of transportation with regards to the vehicle travelling cost, the intermediate facilities renting cost, and the additional cost to compensate the customer that needs to travel to access the intermediate facilities. Because of its complexity, a simulated annealing algorithm is proposed to solve the problem. On the other hand, the modelling approach can be conducted by generating two-phase optimization model approaches, which are the p-median problem and the capacitated vehicle routing problem. The results from both methods are compared in numerical experiments. The results show the effectiveness of 2EVRP-LF compared to the two-phase optimization. Furthermore, the simulated annealing algorithm showed an effective performance in solving 2EVRP-LF.

Reconstruction of Solid-Air Two Phase Flow CT Image Using Sampled Pattern Matching Method

2002 ◽  
Author(s):  
Masahiro Takei ◽  
Hui Li ◽  
Mitsuaki Ochi ◽  
Yoshifuru Saito ◽  
Kiyoshi Horii
Keyword(s):  
Pattern Matching ◽  
Two Phase Flow ◽  
Volume Ratio ◽  
Reconstruction Method ◽  
Phase Flow ◽  
Ct Image ◽  
Matching Method ◽  
Two Phase ◽  
Ill Posed ◽  
Mating Method

A new reconstruction method, which is called sampled pattern mating method (SPM), has been applied to an ill-posed inverse problem of a capacitance-computed tomography for solid air two-phase flow. As a result, the accuracy of the reconstructed image is improved as compared with a conventional Newton-Rampson iterative method. Moreover, the particles volume ratio in solid air two-phase flow calculated by SPM method is more accurate than the conventional method.

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