Computers & Fluids最新文献_第4页

Development of ISPH-FVM coupling method by embedded MHD model to simulate bubble rising in conductive liquids under magnetic field 基于嵌入式MHD模型的ISPH-FVM耦合方法在磁场作用下模拟导电液体气泡上升

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-05 DOI: 10.1016/j.compfluid.2025.106941

Yixiang Xu , Gang Yang , Yulin Xing , Dean Hu

The motion of bubbles in conductive fluid under the external magnetic field is affected by multiple physical fields, so that the flow characteristics of bubbles are usually difficult to predict, which has gradually become a hot topic in magnetohydrodynamics research. In this paper, the dynamic behavior of bubble rising in conductive liquids under magnetic field is simulated by three-dimensional (3D) ISPH-FVM coupling method. The bubble motion is captured by the ISPH particles, while the FVM mesh is used to calculate the flow field. For the combination of magnetohydrodynamics model and ISPH-FVM coupling method, FVM grid is used to solve Maxwell equations combining electric field and magnetic field, and the calculated Lorentz force is introduced into the momentum equation. To verify the accuracy and stability of the present ISPH-FVM coupling model, the Shercliff case, bubble rising under horizontal magnetic field and two horizontal bubbles coalescence are tested. Subsequently, the single bubble rising under different magnetic field directions and intensities is simulated, and the dynamic mechanism behind the morphological changes and rising velocity of the bubble is deeply analyzed. Finally, the influence of different magnetic field directions and intensities on the terminal velocity and bubble shape of rising bubble with different sizes are discussed.

导电性流体中气泡在外磁场作用下的运动受到多个物理场的影响，气泡的流动特性通常难以预测，已逐渐成为磁流体力学研究的热点。本文采用三维（3D） ISPH-FVM耦合方法，模拟了导电液体中气泡在磁场作用下上升的动态行为。气泡运动由ISPH粒子捕获，流场计算采用FVM网格。将磁流体力学模型与ISPH-FVM耦合方法相结合，采用FVM网格求解电场与磁场结合的Maxwell方程，并将计算得到的洛伦兹力引入动量方程。为了验证ISPH-FVM耦合模型的准确性和稳定性，对Shercliff情况、水平磁场下气泡上升和两个水平气泡合并进行了测试。随后，对不同磁场方向和强度下单个气泡的上升过程进行了模拟，深入分析了气泡形态变化和上升速度的动力学机制。最后，讨论了不同磁场方向和强度对不同大小上升气泡终端速度和气泡形状的影响。

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引用次数: 0

Curve boundary algorithms based on interpolation for multiphase lattice Boltzmann method 基于插值的多相晶格玻尔兹曼法曲线边界算法

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-26 DOI: 10.1016/j.compfluid.2025.106954

Dingyu Song , Fu Ling , Yonggang Zhang , Binghai Wen

Boundary treatment is an essential issue in the modelling of fluid flows with high accuracy. While the curved boundary conditions can improve the accuracy of simulating complex geometric boundaries in single-phase flows in the lattice Boltzmann method, they usually lead to significant mass leakage and computational errors in multiphase flow. This is primarily because the traditional curved boundary conditions fail to account for nonlinear density variations in the transition region caused by nonideal effects. This study incorporates the nonideal effect into an interpolation scheme and proposes the interpolation-based curved boundary algorithm for multiphase flow, including linear, quadratic, and cubic interpolation schemes. Static and dynamic multiphase simulations with large density ratios demonstrate that this method effectively improves the computational accuracy of multiphase flow boundary conditions. The required mass compensation is negligible, and the spurious velocity is reduced by an order of magnitude compared to conventional methods.

边界处理是高精度流体流动建模的关键问题。虽然曲面边界条件可以提高晶格玻尔兹曼法模拟单相流动复杂几何边界的精度，但在多相流动中往往会导致较大的质量泄漏和计算误差。这主要是因为传统的弯曲边界条件不能解释由非理想效应引起的过渡区域的非线性密度变化。本研究将非理想效应纳入插值方案，提出了基于插值的多相流曲线边界算法，包括线性、二次和三次插值方案。大密度比的静态和动态多相流模拟结果表明，该方法有效地提高了多相流边界条件的计算精度。所需的质量补偿可以忽略不计，并且与传统方法相比，伪速度降低了一个数量级。

引用次数: 0

Numerical investigation of flow induced by plasma actuators around a circular cylinder in quiescent air under duty-cycle actuation 占空比作用下静空气中等离子体作动器绕圆柱体流动的数值研究

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-24 DOI: 10.1016/j.compfluid.2025.106953

Zihao Zhu, Pau Fradera-Soler, Yalu Zhu, Feng Liu

The flow induced by a pair of Dielectric-Barrier-Discharge (DBD) plasma actuators symmetrically-mounted on a circular cylinder in quiescent air is simulated by solving the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations. A new body-force model for the plasma actuator is developed, which yields significantly improved agreement with experiments. In addition to velocity and vorticity fields, the computations provide time-instantaneous and time-averaged pressure field and pressure and skin friction distributions over the cylinder, which have not been available from existing experiments for this problem. The computational results are analyzed to reveal the relations between the plasma body force, pressure field, velocity, vorticity, forces on the cylinder, and momentum imparted to the flow as they impact the flow control effectiveness for different duty-cycle ratio and frequency of the plasma actuation input. A pair of cumulative vortices is discovered outside the experimental measurement window for the first time by the computations. Regardless of the level of duty-cycle frequency and the detailed near field vortex patterns, the vortices appear to eventually accumulate some distance downstream of the cylinder and move very slowly downstream. The present study is of direct relevance to problems involving vortex shedding and noise production from many circular-shaped aeronautical and civil structures. It helps to provide the necessary fundamental understanding of the flow physics and guidance for future design and optimization of DBD plasma actuators for flow control.

通过求解非定常reynolds - average Navier-Stokes （URANS）方程，模拟了对称安装在圆柱上的一对介质阻挡放电（DBD）等离子体致动器在静止空气中的流动。建立了一种新的等离子体作动器的体力模型，该模型与实验结果吻合较好。除了速度和涡量场之外，计算还提供了时间瞬时和时间平均的压力场以及气缸上的压力和表面摩擦分布，这些都是现有实验无法得到的。通过对计算结果的分析，揭示了在不同占空比和频率下，等离子体体力、压力场、速度、涡量、施加在气缸上的力和传递给流动的动量对流动控制效果的影响关系。通过计算，首次在实验测量窗口外发现了一对累积涡。不管占空比频率的高低和详细的近场涡旋模式如何，涡旋似乎最终会在圆柱体下游积累一定距离，并向下游缓慢移动。本研究直接涉及许多圆形航空和民用结构的涡脱落和噪声产生问题。它有助于为流动物理提供必要的基本理解，并为未来设计和优化用于流动控制的DBD等离子体致动器提供指导。

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引用次数: 0

An all-Mach cell-centered multi-dimensional finite volume numerical scheme for the Euler equations 欧拉方程的全马赫中心多维有限体积数值格式

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-25 DOI: 10.1016/j.compfluid.2025.106951

Alessia Del Grosso , Wasilij Barsukow , Raphaël Loubère , Pierre-Henri Maire

In the context of the numerical approximation of Euler equations, great efforts have been devoted to developing schemes that can accurately reproduce solutions in low Mach number flows. Solutions of classic Finite Volume (FV) schemes are usually plagued by an excessive diffusion as the numerical scheme is not consistent with the limit equations for the Mach number that tends to zero. Instead, a numerical scheme that satisfies such a property is called Asymptotic-Preserving (AP). In this paper, we propose an AP FV scheme for the multi-dimensional Euler equations. In classic FV methods, the numerical approximation of the face flux is obtained by means of a two-state 1D approximate Riemann Solver (RS) in the normal direction to the face. Here, we rely on a node-based flux approximation that exploits a particular RS involving a nodal quantity which depends on all the cells around a given node. Such an idea has been exploited by Barsukow et al. (2023) for the linear acoustic equations. Their method is vorticity-preserving, but its extension to the Euler equations proved to be far from trivial. For such a reason, a change of perspective is needed in the definition of the RS.

在欧拉方程的数值近似的背景下，大量的努力已经投入到开发方案，可以准确地再现解在低马赫数流动。经典有限体积格式的解由于不符合马赫数趋于零的极限方程，通常存在过度扩散的问题。相反，满足这种性质的数值格式称为渐近保持（AP）。本文提出了多维欧拉方程的AP - FV格式。在经典的FV方法中，面通量的数值逼近是通过在面法线方向上的两态一维近似黎曼解算器（RS）获得的。在这里，我们依赖于一个基于节点的通量近似，它利用了一个特定的RS，涉及一个节点数量，这个节点数量取决于给定节点周围的所有细胞。Barsukow等人（2023）在线性声学方程中利用了这种想法。他们的方法是保持涡度的，但将其推广到欧拉方程被证明远非微不足道。因此，在RS的定义中需要改变视角。

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引用次数: 0

Fine-tuning physics-informed neural networks for cavity flows using coordinate transformation 利用坐标变换对腔体流动的物理信息神经网络进行微调

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-27 DOI: 10.1016/j.compfluid.2025.106957

Ryuta Takao , Satoshi Ii

Physics-informed neural networks (PINNs) have attracted attention as an alternative approach to solve partial differential equations using a deep neural network (DNN). Their simplicity and capability allow them to solve inverse problems for many applications. Despite the versatility of PINNs, it remains challenging to reduce their training cost. Using a DNN pre-trained with an arbitrary dataset with transfer learning or fine-tuning is a potential solution. However, a pre-trained model using a different geometry and flow condition than the target may not produce suitable results. This paper proposes a fine-tuning approach for PINNs with coordinate transformation, modelling lid-driven cavity flows with various shapes. We formulate the inverse problem, where the reference data inside the domain and wall boundary conditions are given. A pre-trained PINN model with an arbitrary Reynolds number and shape is used to initialize a target DNN. To reconcile the reference shape with different targets, governing equations as a loss of the PINNs are given with coordinate transformation using a deformation gradient tensor. Numerical examples for various cavity flows with square, rectangular, shear deformed and inflated geometries demonstrate that the proposed fine-tuning approach improves the training convergence compared with a randomly-initialized model. A pre-trained model with a similar geometry to the target further increases training efficiency. These findings are useful for real-world applications such as modelling intra-aneurysmal blood flows in clinical use.

物理信息神经网络（pinn）作为一种利用深度神经网络（DNN）求解偏微分方程的替代方法引起了人们的关注。它们的简单性和功能使它们能够解决许多应用程序的逆向问题。尽管pin具有多功能性，但降低其培训成本仍然具有挑战性。使用带有迁移学习或微调的任意数据集预训练的深度神经网络是一种潜在的解决方案。然而，使用与目标不同的几何形状和流动条件的预训练模型可能无法产生合适的结果。本文提出了一种基于坐标变换的pinn微调方法，对不同形状的盖驱动腔流进行建模。给出了区域内的参考数据和壁面边界条件，给出了反问题的形式。使用一个具有任意雷诺数和形状的预训练PINN模型来初始化目标DNN。为了协调不同目标的参考形状，利用变形梯度张量进行坐标变换，给出了作为pinn损失的控制方程。对方形、矩形、剪切变形和膨胀几何形状的空腔流动进行了数值模拟，结果表明，与随机初始化模型相比，该方法提高了训练收敛性。与目标几何形状相似的预训练模型进一步提高了训练效率。这些发现对于现实世界的应用是有用的，例如模拟临床使用的动脉瘤内血流。

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引用次数: 0

Aerodynamic shape optimization with discretization error control for high-order compressible flow simulations 高阶可压缩流动模拟的离散误差控制气动形状优化

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-16 DOI: 10.1016/j.compfluid.2025.106949

Kush Pandya, Aravind Balan

The shape of an aerospace vehicle significantly influences its performance, and Aerodynamic Shape Optimization (ASO) refines the shape to achieve objectives such as drag reduction and lift improvement. ASO typically combines Computational Fluid Dynamics (CFD) simulations with gradient-based optimization. Adjoint methods can compute gradients independently of the number of shape parameters, making it computationally efficient when optimizing for a large number of shape parameters. For high reliability on the results of ASO, we need accurate evaluation of the objective functions and their gradients. High-order numerical methods, such as the Discontinuous Galerkin (DG) method, provide superior accuracy for compressible flow simulations at a computational cost comparable to traditional methods, making them ideal for ASO. The present study highlights the impact of discretization errors on optimal geometry, emphasizing the need for controlling them in an efficient way during optimization. A novel strategy is proposed that efficiently integrates adjoint-based mesh optimization within the ASO framework that uses a high-order DG method for the flow simulations. The approach ensures that discretization errors in the objective function remain bounded throughout the ASO process by dynamically adapting the meshes based on adjoint-based error estimates. The mesh adaptation is formulated in such a way that one gets optimum meshes with minimal number of elements for a prescribed error tolerance. The strategy results in a multi-fidelity approach where there is an effective utilization of computation cost by progressively refining the mesh as ASO progresses. The effectiveness of the proposed methodology is demonstrated through a comparative analysis with conventional ASO performed on a fixed fine mesh, using a benchmark test case from the AIAA Aerodynamic Design Optimization Discussion Group (ADODG). The results highlight significant improvements in the optimization process’s reliability and computational efficiency.

航空航天飞行器的外形对其性能有很大的影响，气动外形优化（ASO）对外形进行优化，以达到减少阻力和提高升力等目标。ASO通常将计算流体动力学（CFD）模拟与基于梯度的优化相结合。伴随方法可以独立于形状参数的数量计算梯度，使其在优化大量形状参数时计算效率高。为了保证ASO结果的高可靠性，我们需要对目标函数及其梯度进行准确的评估。高阶数值方法，如不连续Galerkin （DG）方法，为可压缩流动模拟提供了更高的精度，而计算成本与传统方法相当，使其成为ASO的理想选择。本研究强调了离散误差对最优几何的影响，强调了在优化过程中有效控制离散误差的必要性。提出了一种新的策略，将基于自伴随的网格优化有效地集成到ASO框架中，使用高阶DG方法进行流动模拟。该方法通过基于伴随误差估计的网格动态自适应，确保目标函数的离散化误差在整个ASO过程中保持有界。网格自适应是以这样一种方式制定的，即在规定的误差容忍度下，使用最少数量的元素获得最佳网格。该策略是一种多保真度方法，通过随着ASO的进行逐步细化网格，有效地利用了计算成本。采用AIAA气动设计优化讨论组（ADODG）的基准测试用例，与在固定细网格上执行的传统ASO进行了对比分析，证明了该方法的有效性。结果表明，优化过程的可靠性和计算效率有了显著提高。

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引用次数: 0

Artificial viscosity based on the velocity gradient components in a 3D Lagrangian Lax-Wendroff scheme 三维拉格朗日Lax-Wendroff格式中基于速度梯度分量的人工粘度

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-13 DOI: 10.1016/j.compfluid.2025.106944

Matěj Klíma, Milan Kuchařík, Richard Liska

In this paper, a new type of artificial viscosity, based on the divergence of velocity gradient, is developed for the Lagrangian Lax-Wendroff cell-centered schemes. Similar approaches led previously to the development of tensor viscosity in methods with staggered grids. The velocity gradient can be split into the compressible, symmetric, and rotational components that each have a different effect on shock waves or rotational flows. We demonstrate the effects of using each component or their combinations on a set of typical hydrodynamics testing problems.

The new artificial viscosity leads to far greater robustness and symmetry compared to the original HLL-type one for the Saltzman test. For treating radial shocks (Noh), the best results are achieved by combination of symmetric and rotational terms, while for the tests involving rotational flow (Taylor-Green vortex) or instability formation (Richtmyer-Meshkov), the compressible part of the velocity gradient is more suitable, as it does not suppress the vorticity of the flow.

本文针对拉格朗日Lax-Wendroff胞心格式，提出了一种基于速度梯度散度的新型人工黏度。类似的方法导致了先前在交错网格方法中的张量粘度的发展。速度梯度可以分为可压缩、对称和旋转三部分，每一部分对激波或旋转流有不同的影响。我们演示了使用每个组件或它们的组合对一组典型的水动力学测试问题的影响。与萨尔茨曼测试中原始的hhl型相比，新的人工粘度具有更大的鲁棒性和对称性。对于处理径向激波（Noh），将对称项和旋转项结合使用可获得最佳结果，而对于涉及旋转流动（Taylor-Green vortex）或不稳定形成（richmyer - meshkov）的测试，速度梯度的可压缩部分更合适，因为它不会抑制流动的涡度。

引用次数: 0

A Markov Matrix iterative splitting algorithm for natural convection 自然对流的马尔可夫矩阵迭代分裂算法

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-05 DOI: 10.1016/j.compfluid.2025.106933

Manira E. Narvaez-Saucedo, Carlos A. López-Villalobos, Manuel A. Ramírez-Cabrera, Eduardo Ramos, Patricio Javier Valades-Pelayo

This work introduces a novel Markov Matrix Iterative Splitting Algorithm (MISA), a probabilistic operator splitting Monte Carlo approach designed for simulating natural convection in incompressible flows within the continuum regime. This approach effectively captures the nonlinear convective transport and stochastic diffusion while enforcing global incompressibility, without requiring mesh generation or matrix inversions common to deterministic solvers. Variance reduction techniques and a Multi-Level Monte Carlo framework improve convergence and stability. MISA naturally handles complex geometries with internal obstacles, incorporated effortlessly by excluding walkers inside them and imposing boundary conditions on their surfaces. Benchmark natural convection simulations in square cavities demonstrate MISA’s accuracy and computational efficiency compared to traditional finite-volume solvers. The method reliably resolves convective flow structures and temperature fields, highlighting its promising potential for complex fluid-thermal transport problems in irregular domains

本文介绍了一种新颖的马尔可夫矩阵迭代分裂算法（MISA），这是一种概率算子分裂蒙特卡罗方法，用于模拟连续区内不可压缩流动中的自然对流。这种方法有效地捕获了非线性对流传输和随机扩散，同时增强了全局不可压缩性，而不需要网格生成或确定性求解器常见的矩阵反转。方差减少技术和多层蒙特卡罗框架提高收敛性和稳定性。MISA自然地处理带有内部障碍物的复杂几何形状，通过排除其中的行人并在其表面施加边界条件而毫不费力地结合在一起。与传统的有限体积求解器相比，在方形腔中进行的基准自然对流模拟证明了MISA的准确性和计算效率。该方法可靠地求解对流结构和温度场，突出了其在不规则区域复杂流体-热输运问题中的应用前景

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引用次数: 0

Non-orthogonal plane-marching parabolized stability equations for the secondary instability of crossflow vortices 横流涡旋二次不稳定性的非正交平面推进抛物化稳定性方程

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-17 DOI: 10.1016/j.compfluid.2025.106947

Koen J. Groot , Jordi Casacuberta , Stefan Hickel

A detailed derivation, analysis, and verification is given for the non-orthogonal, plane-marching Parabolized Stability Equations (PSE) approach. In applying the approach to a flow distorted by a medium-amplitude crossflow vortex, we determine its linear secondary instability mechanisms. We show that converged solutions can be achieved for a broad frequency range with an existing stabilization method for the line-marching PSE approach. We verify that 1) solutions converge versus grid size in all dimensions, 2) primary disturbance solutions agree with line-marching PSE results, and 3) secondary disturbance solutions match amplitude and growth-rate evolution of reference Direct Numerical Simulation (DNS) results. We show how and why the type-II instability displays a delayed neutral point when modeled with the plane-marching approach versus the considered local stability approaches, whether the streamwise evolution of the distorted base flow is accounted for or not. This may explain why the type-II disturbance is scarcely captured by DNS in the literature.

对非正交的平面行进抛物稳定方程（PSE）方法进行了详细的推导、分析和验证。将该方法应用于中幅横流涡畸变的流动，确定了其线性二次不稳定机制。我们证明了用现有的线推进PSE方法的稳定方法可以在很宽的频率范围内获得收敛解。我们验证了1)解决方案在所有维度上与网格大小收敛，2)主要干扰解决方案与线推进PSE结果一致，3)次要干扰解决方案与参考直接数值模拟（DNS）结果的振幅和增长率演变相匹配。我们展示了ii型不稳定性如何以及为什么在使用平面行进方法与考虑的局部稳定方法建模时显示延迟中性点，无论是否考虑了扭曲基流的流向演变。这也许可以解释为什么在文献中，DNS几乎没有捕捉到ii型干扰。

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引用次数: 0

High-order gas-kinetic scheme with two-derivative-based time discretization for compressible flows 可压缩流动的高阶气体动力学双导数时间离散格式

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2026-02-15 Epub Date: 2025-12-18 DOI: 10.1016/j.compfluid.2025.106950

Qiushuo Qin , Jie Wu , Lan Jiang

In this paper, an efficient high-order gas-kinetic scheme for compressible flow simulation is presented. It combines the fifth-order targeted essentially non-oscillatory (TENO) reconstruction with a circular-function-based gas kinetic flux solver (C-GKFS), which enhances the resolution of flow field details while maintaining stability and high accuracy. To further improve the efficiency of time advancement, this work introduces two-derivative, multi-step or multi-stage time discretization schemes with strong stability preserving time coefficients. These schemes are combined with the Lax-Wendroff spatio-temporal coupling strategy, which effectively reduce the number of function evaluations, lowers the computational complexity, and improves the overall robustness. The numerical results of several typical examples verify the advantages of the proposed method in terms of resolution, stability and efficiency, especially in the simulations of the shock-bubble interaction and the inviscid 3D Taylor-Green vortex, which show good potential for applications in complex flows.

本文提出了一种高效的高阶气体动力学可压缩流动模拟格式。它将五阶定向非振荡（TENO）重建与基于圆函数的气体动力学通量求解器（C-GKFS）相结合，提高了流场细节的分辨率，同时保持了稳定性和高精度。为了进一步提高时间推进的效率，本文引入了具有强保稳时间系数的二阶、多步或多阶段时间离散化方案。这些方案与Lax-Wendroff时空耦合策略相结合，有效减少了函数求值次数，降低了计算复杂度，提高了整体鲁棒性。几个典型算例的数值结果验证了该方法在分辨率、稳定性和效率方面的优势，特别是在激波-气泡相互作用和无粘三维泰勒-格林涡的模拟中，显示出良好的应用潜力。

引用次数: 0