共查询到20条相似文献,搜索用时 62 毫秒
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本文结合高精度TVD格式的数值通量和时间进展多步法给出了一种求解定常流问题的数值方法。同时给出一些特殊处理来加快数值解的收敛速度。本文用以上方法计算了翼型跨音速绕流问题,结果表明此方法具有分辨率高,收敛速度较快之性质。 相似文献
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可压缩粘性流动中双方程湍流模型的选择 总被引:13,自引:1,他引:12
应用本文作者提出的高收敛率、高精度和高分辨率方法求解可压缩粘性流动问题时选用了k-∈、k-ω和q-ω等三种考虑了可压缩性的双方程湍流模型.综合比较了模型本身以及边界条件提法的难易程度,它们对求解复杂流动以及捕捉各种间断面和滑移面的能力,对初始流场的依赖程度,对收敛速率、CPU时间以及对解的精度和分辨率等的影响。本研究为三维非定常湍流计算提供了选择湍流模型的成功经验. 相似文献
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对突扩燃烧室这一典型工程燃烧装置内的湍流预混反应流进行了数值模拟。时平均控制方程组的封闭采用k-ε湍流输运模型和EBU-Arhenius湍流反应模型。模拟结果给出了突扩燃烧室内湍流预混反应流的气体时均流场、组分浓度场与温度场的分布。通过数值模拟结果与实验的比较对EBU-Arhenius模型进行了讨论与评价。 相似文献
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喷雾湍流燃烧过程中,液滴、湍流和化学反应之间强烈耦合,物理化学机理非常复杂。本文将速度-标量-频率联合概率密度函数JPDF输运方程方法应用于两相喷雾湍流反应流问题,利用火焰面模型解耦流动和化学反应动力学的耦合关系,建立起相应的数值计算模型。采用Monte-Carlo数值计算方法,针对澳大利亚悉尼大学Masri等人以甲醇为燃料所进行的湍流喷雾燃烧值班火焰这一试验进行了数值模拟,通过与Fluent下的计算结果及试验结果的对比分析,验证了本文所建模型的准确性。 相似文献
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颗粒湍流扩散的数值模拟 总被引:3,自引:0,他引:3
1引言颗粒湍流扩散是气固两相流中的一个重要的研究课题,近年来,国外有大量文献报道这方面的工作。因为颗粒的湍流扩散的研究的一个基本问题就是湍流的描述,它一方面可以来检验湍流描述的正确性;另一方面,该问题是气固两相流理论中,特别是颗粒群轨道模型中一个难点。描述湍流大体上可分为两种方法。一是直接数值模拟方法(DNS),J.B.Mclaughlin对管流内颗粒沉降的研究就基于直接数值模拟山,K.D.squires和J.K.Eaton对颗粒扩散的研究也基于DNS[2],DNS一般只适用于低Reynolds数。另一方面,用随机方法来模拟湍流,该… 相似文献
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Simulation of Viscous Flows Around a Moving Airfoil by Field Velocity Method with Viscous Flux Correction 下载免费PDF全文
Ning Gu Zhiliang Lu & Tongqing Guo 《advances in applied mathematics and mechanics.》2012,4(3):294-310
Based on the field velocity method, a novel approach for simulating unsteady
pitching and plunging motion of an airfoil is presented in this paper. Responses
to pitching and plunging motions of the airfoil are simulated under different
conditions. The obtained results are compared with those of moving grid
method and good agreement is achieved. In the conventional field velocity method,
the Euler solver is usually used to simulate the movement of the airfoil. However,
when viscous effect is considered, unsteady Navier-Stokes equations have to be
solved and the viscous flux correction must be taken into account. In this work, the
viscous flux correction is introduced into the conventional field velocity method
when non-uniform grid speed distribution is occurred. Numerical experiments for
the flow around NACA0012 airfoil showed that the proposed approach can well
simulate viscous moving boundary flow problems. 相似文献
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A Switch Function-Based Gas-Kinetic Scheme for Simulation of Inviscid and Viscous Compressible Flows 下载免费PDF全文
Yu Sun Shu Chang Liming Yang & C. J. Teo 《advances in applied mathematics and mechanics.》2016,8(5):703-721
In this paper, a switch function-based gas-kinetic scheme (SF-GKS) is presented
for the simulation of inviscid and viscous compressible flows. With the finite
volume discretization, Euler and Navier-Stokes equations are solved and the SF-GKS
is applied to evaluate the inviscid flux at cell interface. The viscous flux is obtained by
the conventional smooth function approximation. Unlike the traditional gas-kinetic
scheme in the calculation of inviscid flux such as Kinetic Flux Vector Splitting (KFVS),
the numerical dissipation is controlled with a switch function in the present scheme.
That is, the numerical dissipation is only introduced in the region around strong shock
waves. As a consequence, the present SF-GKS can well capture strong shock waves
and thin boundary layers simultaneously. The present SF-GKS is firstly validated by
its application to the inviscid flow problems, including 1-D Euler shock tube, regular
shock reflection and double Mach reflection. Then, SF-GKS is extended to solve viscous
transonic and hypersonic flow problems. Good agreement between the present
results and those in the literature verifies the accuracy and robustness of SF-GKS. 相似文献
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研究如何在非结构网格上进行Navier Stokes(N-S)方程湍流计算.采用格心有限体积方法离散N-S方程.为了适应非结构网格,计算所用的湍流模型特别选用Baldwin Barth(B-B)单方程模型.此模型由一个单一的具有源项的对流扩散方程组成.为了能在非结构网格上求解B B单方程模型,提出一显式有限体积格式,并直接对带源项的格式进行稳定性分析,得到了相应的时间步长限制条件.最后以平板、RAE 2822翼型、多段翼型绕流等数值算例验证了计算方法的有效性. 相似文献
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本文开发了一套基于非结构网格的间断有限元方法(DG)程序,并对与单元形状无关的斜率限制器进行了研究。此程序支持多种网格类型,能够方便应用于具有混合单元的非结构网格,具有处理复杂几何结构的能力,为研究叶轮机械内部复杂流动现象提供了有效的研究工具。本文利用该程序对若干典型无黏和黏性问题进行数值模拟,结果表明,该程序具有较高的可信度,能够处理具有混合单元的非结构网格,并给出良好的数值模拟结果。 相似文献
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In this paper, a hybrid lattice Boltzmann flux solver (LBFS) is proposed for
simulation of viscous compressible flows. In the solver, the finite volume method is
applied to solve the Navier-Stokes equations. Different from conventional Navier-Stokes
solvers, in this work, the inviscid flux across the cell interface is evaluated by
local reconstruction of solution using one-dimensional lattice Boltzmann model, while
the viscous flux is still approximated by conventional smooth function approximation.
The present work overcomes the two major drawbacks of existing LBFS [28–31], which
is used for simulation of inviscid flows. The first one is its ability to simulate viscous
flows by including evaluation of viscous flux. The second one is its ability to effectively
capture both strong shock waves and thin boundary layers through introduction of a
switch function for evaluation of inviscid flux, which takes a value close to zero in
the boundary layer and one around the strong shock wave. Numerical experiments
demonstrate that the present solver can accurately and effectively simulate hypersonic
viscous flows. 相似文献
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湍流模型在复杂流场数值模拟中的应用 总被引:5,自引:0,他引:5
采用4种湍流模型:代数Baldwin Lomax(B-L)模型、半方程Johnson King(J-K)模型的两个版本(J-K90A和J K92)以及两方程k-g模型,分别数值模拟了导弹超音速流动、NASATND-712标模和民机翼身组合体(两区C-O网格)跨音速流动.采用中心有限体积和多步Runge-Kutta方法数值积分三维可压缩雷诺平均Navier-Stokes(N-S)方程组.k-g湍流模型方程的求解采用类似于N-S方程组的方法进行.所有湍流模型均能很好地模拟附体及小分离流动;对于大攻角、分离剧烈的导弹流动,k-g和J-K92模型与实验吻合更好;B-L模型在模拟民机跨音速流动时,它所捕捉的激波位置较其余3种模型靠后.利用多块网格模拟民机翼身组合体流场时,k-g模型的模拟能力强于其余3种模型. 相似文献
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本文应用大气压等离子体射流传热与流动的三维数学模型,在相同初始条件下,计算得到了采用不同湍流模型时氩等离子体射流对称轴线上的温度、速度及空气质量分数分布,并与文献中同等条件下的实验结果进行了比较,结果表明采用标准κ-ε模型和Realizableκ-ε模型时与实验结果相差较大,而采用RNGκ-ε湍流模型时模拟结果与实验数... 相似文献