Computer Physics Communications最新文献

{"title":"The hybrid anti-symmetrized coupled channels method (haCC) for the tRecX code","authors":"Hareesh Chundayil ,&nbsp;Vinay P. Majety ,&nbsp;Armin Scrinzi","doi":"10.1016/j.cpc.2024.109279","DOIUrl":"https://doi.org/10.1016/j.cpc.2024.109279","url":null,"abstract":"<div><p>We present a new implementation of the hybrid antisymmetrized Coupled Channels (haCC) method in the framework of the tRecX (Scrinzi, 2022 <span>[6]</span>). The method represents atomic and molecular multi-electron functions by combining CI functions, Gaussian molecular orbitals, and a numerical single-electron basis. It is suitable for describing high harmonic generation and the strong-field dynamics of ionization. Fully differential photoemission spectra are computed by the tSurff method. The theoretical background of haCC is outlined and key improvements compared to its original formulation are highlighted. We discuss control of over-completeness resulting from the joint use of the numerical basis and Gaussian molecular orbitals by pseudo-inverses based on the Woodbury formula. Further new features of this tRecX release are the iSurff method, new input features, and the AMOS gateway interface. The mapping of haCC into the tRecX framework for solving the time-dependent Schrödinger equation is shown. Use, performance, and accuracy of haCC are discussed on the examples of high-harmonic generation and strong-field photo-emission by short laser pulses impinging on the Helium atom and on the linear molecules <span><math><msub><mrow><mi>N</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> and <em>CO</em>.</p></div><div><h3>Program summary</h3><p><em>Program title:</em> tRecX — time-dependent Recursive indeXing (tRecX=tSurff+irECS)</p><p><em>CPC Library link to program files:</em> <span>https://doi.org/10.17632/m9g2jc82sw.1</span><svg><path></path></svg></p><p><em>Developer's repository link:</em> <span>https://gitlab.physik.uni-muenchen.de/AG-Scrinzi/tRecX</span><svg><path></path></svg></p><p><em>Licensing provisions:</em> GNU General Public License 2</p><p><em>Programming language:</em> C++</p><p><em>External libraries:</em> Eigen, arpack, lapack, blas, boost, FFTW (optional)</p><p><em>Journal Reference of previous version:</em> A. Scrinzi, Comp. Phys. Comm., 270:108146, 2022.</p><p><em>Does the new version supersede the previous version:</em> Yes</p><p><em>Reasons for the new version:</em> Major new functionality: haCC — hybrid antisymmetrized coupled channels method</p><p><em>Summary of revisions:</em> Main additions are haCC and iSurff. Code usage and compilation were improved.</p><p><em>Nature of problem:</em> tRecX is a general solver for time-dependent Schrödinger-like problems, with applications mostly in strong field and attosecond physics. There are no technical restrictions on the spatial dimension of the problem with up to 6 spatial dimensions realized in the strong-field double ionization of Helium. Gaussian-based quantum chemical multi-electron atomic and molecular structure can be combined with the numerical basis. A selection of coordinate systems is available and any Hamiltonian involving up to second derivatives and arbitrary up to three dimensional potentials can be defined on input by simple scripts.</p><p><em>Solutio","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010465524002029/pdfft?md5=4816c45cdf126acf37592d039f9ea41b&pid=1-s2.0-S0010465524002029-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141429339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Principal Landau determinants","authors":"Claudia Fevola ,&nbsp;Sebastian Mizera ,&nbsp;Simon Telen","doi":"10.1016/j.cpc.2024.109278","DOIUrl":"10.1016/j.cpc.2024.109278","url":null,"abstract":"<div><p>We reformulate the Landau analysis of Feynman integrals with the aim of advancing the state of the art in modern particle-physics computations. We contribute new algorithms for computing Landau singularities, using tools from polyhedral geometry and symbolic/numerical elimination. Inspired by the work of Gelfand, Kapranov, and Zelevinsky (GKZ) on generalized Euler integrals, we define the principal Landau determinant of a Feynman diagram. We illustrate with a number of examples that this algebraic formalism allows to compute many components of the Landau singular locus. We adapt the GKZ framework by carefully specializing Euler integrals to Feynman integrals. For instance, ultraviolet and infrared singularities are detected as irreducible components of an incidence variety, which project dominantly to the kinematic space. We compute principal Landau determinants for the infinite families of one-loop and banana diagrams with different mass configurations, and for a range of cutting-edge Standard Model processes. Our algorithms build on the <span>Julia</span> package <span>Landau.jl</span> and are implemented in the new open-source package <span>PLD.jl</span> available at <span>https://mathrepo.mis.mpg.de/PLD/</span><svg><path></path></svg>.</p></div><div><h3>Program summary</h3><p><em>Program title:</em> <span>PLD.jl</span></p><p><em>CPC Library link to program files:</em> <span>https://doi.org/10.17632/7h5644mm4n.1</span><svg><path></path></svg></p><p><em>Developer's repository link:</em> <span>https://mathrepo.mis.mpg.de/PLD/</span><svg><path></path></svg></p><p><em>Licensing provisions:</em> Creative Commons by 4.0</p><p><em>Programming language:</em> <span>Julia</span></p><p><em>Supplementary material:</em> The repository includes the source code with documentation (PLD_code.zip), a jupyter notebook tutorial providing installation and usage instructions (PLD_notebook.zip), a database containing the output of our algorithm on 114 examples of Feynman integrals (PLD_database.zip).</p><p><em>Nature of problem:</em> A fundamental challenge in scattering amplitude is to determine the values of complexified kinematic invariants for which an amplitude can develop singularities. Bjorken, Landau, and Nakanishi wrote a system of polynomial constraints, nowadays known as the Landau equations. This project aims to rigorously revisit the Landau analysis of the singularity locus of Feynman integrals with a practical view towards explicit computations.</p><p><em>Solution method:</em> We define the principal Landau determinant (PLD), which is a variety inspired by the work of Gelfand, Kapranov, and Zelevinsky (GKZ). We conjecture that it provides a subset of the singularity locus, and we implement effective algorithms to compute its defining equation explicitly.</p><p><em>References:</em> OSCAR <span>[1]</span>, HomotopyContinuation.jl <span>[2]</span>, Landau.jl <span>[3]</span></p></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":7.2,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141410214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoupling numerical method based on deep neural network for nonlinear degenerate interface problems","authors":"Chen Fan,&nbsp;Muhammad Aamir Ali,&nbsp;Zhiyue Zhang","doi":"10.1016/j.cpc.2024.109275","DOIUrl":"10.1016/j.cpc.2024.109275","url":null,"abstract":"<div><p>Many practical problems, including modeling composite materials, nuclear waste disposal, oil reservoir simulations, and flows in porous medium, commonly involve interface problems. However, the solution to interface problems with discontinuous coefficients of PDEs using fully decoupled numerical methods is challenging. The main objective is to solve the interface problems with fully decoupled numerical methods. This paper proposes an efficient decoupled numerical method for solving degenerate interface problems with double singularities. First, we divide the whole domain into singular and regular subdomains. Then, we use the Deep Neural Network (DNN) to find the solution on the singular subdomain and approximate the solution on the regular subdomain using the finite difference method. The scheme combines the solutions of singular and regular subdomains, which is an exciting idea. The key to the new approach is to split nonlinear degenerate partial differential equations with an interface into two independent boundary value problems based on deep learning. In this way, the expansion of the solution on the singular domain does not contain undetermined parameters, and two independent boundary value problems can be solved with any well-known traditional numerical methods. The main advantage of the proposed scheme is that we not only get the order of convergence of the degenerate interface problems on the whole domain, but we also can calculate <strong>VERY BIG</strong> jump ratio (such as <span><math><msup><mrow><mn>10</mn></mrow><mrow><mn>12</mn></mrow></msup><mo>:</mo><mn>1</mn></math></span> or <span><math><mn>1</mn><mo>:</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>12</mn></mrow></msup></math></span>) for the interface problems including degenerate and non-degenerate cases. Finally, with examples, we demonstrate the efficiency and accuracy of methods for 1 and 2D problems. It is also interesting that the proposed method is valid for the interface problems with degenerate and non-degenerate cases, we show it with some examples.</p></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141410638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear elastic scattering of protons below 250 MeV in FLUKA v4-4.0 and its role in single-event-upset production in electronics","authors":"Alexandra-Gabriela Şerban ,&nbsp;Andrea Coronetti ,&nbsp;Rubén García Alía ,&nbsp;Francesc Salvat Pujol ,&nbsp;FLUKA.CERN Collaboration","doi":"10.1016/j.cpc.2024.109276","DOIUrl":"https://doi.org/10.1016/j.cpc.2024.109276","url":null,"abstract":"<div><p>FLUKA is among the general-purpose codes for the Monte Carlo simulation of radiation transport that are routinely employed to estimate the production of single-event-upsets (SEUs) in commercial static random access memories (SRAMs) exposed to radiation. Earlier studies concerning the production of SEUs in commercial SRAMs under proton irradiation revealed very good agreement between experimental measurements and FLUKA estimates of the SEU production cross section for proton energies above 20-30 MeV. However, at lower proton energies, where the cross section for SEU production in such low-critical-charge components increases drastically, a FLUKA underestimation of up to two orders of magnitude was observed. Preliminary analyses indicated that this underestimation was in great measure due to the lack of nuclear elastic scattering of protons below 10 MeV in FLUKA up to version 4-3.4. To overcome this limitation, a new model for the nuclear elastic scattering of protons has been developed, combining partial-wave analyses and experimental angular distributions. This newly developed model has been included in FLUKA v4-4.0, and leads to an order-of-magnitude improvement in the agreement between FLUKA and experimental cross sections for the production of SEUs in SRAMs under proton irradiation in the 1–10 MeV energy domain.</p></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010465524001991/pdfft?md5=8dd5bff6dacad33598ad24bc79c8737e&pid=1-s2.0-S0010465524001991-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141429348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ScaleLat: A chemical structure matching algorithm for mapping atomic structure of multi-phase system and high entropy alloys","authors":"Nan Li ,&nbsp;Haoliang Liu ,&nbsp;Sateng Li ,&nbsp;Junming Guo ,&nbsp;Qianwu Li ,&nbsp;Fangjie Shi ,&nbsp;Yefei Li ,&nbsp;Bing Xiao","doi":"10.1016/j.cpc.2024.109265","DOIUrl":"https://doi.org/10.1016/j.cpc.2024.109265","url":null,"abstract":"<div><p>ScaleLat (Scale Lattice) is a computer program written in C for performing the atomic structure analysis of multi-phase system or high entropy alloys (HEAs). The program implements an atomic cluster cell extraction algorithm to obtain all symmetry independent characteristic atomic cluster cells for the complex atomic configurations which are usually obtained from molecular dynamics or kinetic Monte-Carlo simulations at nanoscale or mesoscopic scale. ScaleLat implements an efficient and unique chemical structure matching algorithm to match all extracted atomic clusters from a large supercell (&gt;10⁴ atoms) to a representative small one (∼ 10³ or less), providing the possibility to directly use the highly accurate quantum mechanical methods to study the electronic, magnetic, and mechanical properties of multi-component alloys for complex microstructures. We demonstrate the capability of ScaleLat code by conducting both the atomic structure matching analysis for Fe-12.8 at.% Cr binary alloy and equiatomic CrFeCoNiCu high entropy alloy, successfully obtaining the representative supercells containing 10²∼10³ atoms for two systems. The reliability of the proposed chemical structure matching scheme is tested and confirmed by calculating the electronic structures of both examples using trial supercells with various sizes. Overall, ScaleLat program provides a universal platform to efficiently map all essential chemical structures of large complex atomic structures to a relatively easy-handling small supercell for quantum mechanical calculations of various user interested properties.</p></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":7.2,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141434726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Code for molecular dynamics simulation of two dimensional Mercedes-Benz water model","authors":"Peter Ogrin ,&nbsp;Cristiano L. Dias ,&nbsp;Tomaz Urbic","doi":"10.1016/j.cpc.2024.109267","DOIUrl":"https://doi.org/10.1016/j.cpc.2024.109267","url":null,"abstract":"<div><p>The Mercedes-Benz (MB) water model is a simple two-dimensional toy model of water that can reproduce many of the anomalous properties of water. Within the model, the water particles are represented as Lennard-Jones disks with explicitly added orientation-dependent interactions that mimic the formation of hydrogen bonds. Due to the simple implementation of the MB model in Monte Carlo simulations, it was mainly studied with Monte Carlo simulations in different ensembles. The implementation of the model in molecular dynamics simulations is not trivial. In this paper we present the code for molecular dynamics simulations. The structural and thermodynamic properties of the model were calculated using molecular dynamics and compared with data from Monte Carlo simulations to confirm that the molecular dynamics code works correctly. We also used molecular dynamics to calculate the dynamic properties of the model. The Fortran source code of our molecular dynamics simulation of the MB water model is provided.</p></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010465524001905/pdfft?md5=c7faabbec1a5c5bf10101d941faa7630&pid=1-s2.0-S0010465524001905-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141313564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MAM-STM: A software for autonomous control of single moieties towards specific surface positions","authors":"Bernhard Ramsauer,&nbsp;Johannes J. Cartus,&nbsp;Oliver T. Hofmann","doi":"10.1016/j.cpc.2024.109264","DOIUrl":"https://doi.org/10.1016/j.cpc.2024.109264","url":null,"abstract":"<div><p>In this publication we introduce MAM-STM, a software to autonomously manipulate arbitrary moieties towards specific positions on a metal surface utilizing the tip of a scanning tunneling microscope (STM). Finding the optimal manipulation parameters for a specific moiety is challenging and time consuming, even for human experts. MAM-STM combines autonomous data acquisition with a sophisticated Q-learning implementation to determine the optimal bias voltage, the z-approach distance, and the tip position relative to the moiety. This then allows to arrange single molecules and atoms at will. In this work, we provide a tutorial based on a simulated response to offer a comprehensive explanation on how to use and customize MAM-STM. Additionally, we assess the performance of the machine learning algorithm by benchmarking it within a simulated stochastic environment.</p></div><div><h3>PROGRAM SUMMARY</h3><p>Program title: MAM-STM</p><p>CPC Library link to program files: (to be added by Technical Editor)</p><p>Developer's repository link: https://gitlab.tugraz.at/software_public/mam_stm.git</p><p>Code Ocean capsule: (to be added by Technical Editor)</p><p>Licensing provisions: GNU General Public License 3 (GPL)</p><p>Programming language: Python 3</p><p>Nature of problem: Achieving precise control over the arrangement of individual molecules on surfaces is essential for advancing nanofabrication and understanding molecular interaction processes. While self-assembly offers a method for forming nanostructures, achieving arbitrary arrangements of moieties remains difficult. Current approaches, such as scanning probe microscopy (SPM), require extensive manual intervention and precise control is difficult to achieve consistently due to the stochastic nature of quantum mechanical systems at the nanoscale. Thus, learning to manipulate several moieties in order to build even relatively small structures is challenging and time consuming and the automation through conventional expert systems is hindered by the lack of prior knowledge about the surface-moiety interaction processes.</p><p>Solution method: This scenario is ideal for machine learning algorithms, like reinforcement learning (RL), which do not require an underlying model but are able to autonomously learn the optimal manipulation parameters by performing manipulations directly at the machine. Introducing MAM-STM, which stands for Molecular and Atomic Manipulation via Scanning Tunneling Microscopy. MAM-STM allows to control molecules and atoms by learning the manipulation parameters for either vertical or lateral manipulations. However, the vast number of manipulation parameter combinations and the inefficient learning procedure of RL agents exhibit several challenges. MAM-STM overcomes these challenges with an autonomous masking routine that eliminates manipulation parameters that induce structural changes to the moiety or lift it off the surface. Additionally, a sophisticated Q-learning approach ","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010465524001875/pdfft?md5=74c3002522a3586528e738564a9ff30d&pid=1-s2.0-S0010465524001875-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141429351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FENNECS: A novel particle-in-cell code for simulating the formation of magnetized non-neutral plasmas trapped by electrodes of complex geometries","authors":"G. Le Bars ,&nbsp;J. Loizu ,&nbsp;S. Guinchard ,&nbsp;J.-Ph. Hogge ,&nbsp;A. Cerfon ,&nbsp;S. Alberti ,&nbsp;F. Romano ,&nbsp;J. Genoud ,&nbsp;P. Kamiński","doi":"10.1016/j.cpc.2024.109268","DOIUrl":"https://doi.org/10.1016/j.cpc.2024.109268","url":null,"abstract":"<div><p>This paper presents the new 2D electrostatic particle-in-cell code FENNECS developed to study the formation of magnetized non-neutral plasmas in geometries with azimuthal symmetry. This code has been developed in the domain of gyrotron electron gun design, but solves general equations and can be applied in other domains of plasma physics. FENNECS is capable of simulating electron-neutral collisions using a Monte Carlo approach and considers both elastic and inelastic (ionization) processes. It is also capable of solving the Poisson equation on domains with arbitrary geometries with either Dirichlet or natural boundary conditions. The Poisson solver is based on a meshless Finite Element Method, called web-splines, based on b-splines of any order, and used for the first time in the domain of plasma physics. In addition, the effect of fast ions colliding with the electrodes and causing ion induced electron emission at the electrode surfaces has been implemented in the code. In this paper, the governing equations solved by FENNECS and the numerical methods used to solve them are presented. A number of verification cases are then reported. Finally, the parallelization scheme used in FENNECS and its parallel scalability are presented.</p></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010465524001917/pdfft?md5=d12b899e7ef4cc6503231cb81213f8f2&pid=1-s2.0-S0010465524001917-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141313565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Fast Exact Algorithm for Neutrino Oscillation in Constant Matter Density” [Computer Physics Communications volume 300 (2024) 109200]","authors":"James Page","doi":"10.1016/j.cpc.2024.109262","DOIUrl":"https://doi.org/10.1016/j.cpc.2024.109262","url":null,"abstract":"","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010465524001851/pdfft?md5=dbffac2285cea4454d6759b98a9b4a7c&pid=1-s2.0-S0010465524001851-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141250838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A particle-resolved direct numerical simulation method for the compressible gas flow and arbitrary shape solid moving with a uniform framework","authors":"Baoqing Meng ,&nbsp;Junsheng Zeng ,&nbsp;Shuai Li ,&nbsp;Baolin Tian ,&nbsp;Jinhong Liu","doi":"10.1016/j.cpc.2024.109266","DOIUrl":"10.1016/j.cpc.2024.109266","url":null,"abstract":"<div><p>Compressible particle-resolved direct numerical simulations (PR-DNS) are widely used in explosion-driven dispersion of particles simulations, multiphase turbulence modelling, and stage separation for two-stage-to-orbit vehicles. The direct forcing immersed boundary method (IBM) is a promising method and widely applied in low speed flow while there is few research regarding compressible flows. We developed a novel IBM to resolve supersonic and hypersonic gas flows interacting with irregularly shaped multi-body particle. The main innovation is that current method can solve the interaction of particles and high-speed fluids, particle translation and rotation, and collision among complex-shaped particles within a uniform framework. Specially, high conservation and computation consumption are strictly satisfied, which is critical for resolving the high speed compressible flow feature. To avoid the non-physical flow penetration around particle surface, an special iterative algorithm is specially derived to handle the coupling force between the gas and particles. The magnitude of the velocity difference error could be reduced by 6–8 orders compared to that of a previous method. Additionally, aerodynamic force integration was achieved using the momentum equation to ensure momentum conservation for two-phase coupling. A high-efficiency cell-type identification method for each step was proposed, and mapping among LPs and cells was used again to select the immersed cells. As for the collision force calculation, the complex shape of a particle was represented by a cloud of LPs and the mapping of LPs and cells was used to reduce the complexity of the algorithm for contact searching. The repetitive use of the mapping relationship could reduce the internal memory and improve the efficiency of the proposed algorithm. Moreover, various verification cases were conducted to evaluate the simulation performance of the proposed algorithm, including two- and three-dimensional moving and motionless particles with regular and complex shapes interacting with high-speed flow. Specifically, an experiment involving a shock passing through a sphere was designed and conducted to provide high-precision data. The corresponding results of the large-scale numerical simulation agree well with those obtained experimentally. The current method supports flow simulations at a particle-resolved scale in engineering.</p></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141233316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}