排序方式: 共有23条查询结果,搜索用时 203 毫秒
1.
A mass conservative well‐balanced reconstruction at wet/dry interfaces for the Godunov‐type shallow water model 下载免费PDF全文
This paper presents a novel mass conservative, positivity preserving wetting and drying treatment for Godunov‐type shallow water models with second‐order bed elevation discretization. The novel method allows to compute water depths equal to machine accuracy without any restrictions on the time step or any threshold that defines whether the finite volume cell is considered to be wet or dry. The resulting scheme is second‐order accurate in space and keeps the C‐property condition at fully flooded area and also at the wet/dry interface. For the time integration, a second‐order accurate Runge–Kutta method is used. The method is tested in two well‐known computational benchmarks for which an analytical solution can be derived, a C‐property benchmark and in an additional example where the experimental results are reproduced. Overall, the presented scheme shows very good agreement with the reference solutions. The method can also be used in the discontinuous Galerkin method. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
2.
3.
本文研究了二维黏性流体薄膜沿非平整不均匀加热基底流动时非线性表面波的演化及其流动稳定性.利用长波摄动法推导出非平整线性加热基底上非线性表面波的零阶和一阶演化方程,基于所得演化方程,绘制出正弦波纹基底上液膜的表面波形图,并研究液膜流动的线性稳定性,分析了各无量纲参数对液膜线性稳定性的影响.分析结果表明:在正弦波纹基底上,液膜自由表面随同壁面作相同频率的正弦型波动,且液膜厚度沿流动方向逐渐变小;Marangoni数为稳定影响因素,随Marangoni数的增大,液膜稳定区域增大;Peclet数和倾角θ均为不稳定影响因素,随Peclet数和倾角θ的增大,液膜稳定区域减小;在非平整基底的波峰和波谷处,Peclet数、Marangoni数和倾角θ对稳定性的影响趋势一致,但基底波谷处的液膜稳定区域小于波峰处区域,流动更易失稳. 相似文献
4.
浅析二阶齐次线性变系数微分方程的一个可积类型 总被引:1,自引:0,他引:1
姬志飞 《应用数学与计算数学学报》2006,20(1):125-128
本文讨论了二阶齐次线性变系数微分方程的特殊形式,给出了这种微分方程的一个可积类型. 相似文献
5.
6.
逻辑系统G3在非均匀概率空间下命题的真度理论 总被引:2,自引:0,他引:2
在离散概率测度空间下定义了三值逻辑(p,q,r)测度,并相应地定义了命题逻辑系统中公式的真度概念;在三值逻辑(1/6.1/3.1/2)测度和(1/7.2/7.4/7)测度下证明了命题逻辑系统G3中全体公式的真度值之集在[0.1]上是稠密的,并给出真度的表达式;利用真度定义公式的相似度和一种伪距离,为—般离散概率空间下三值命题的近似推理理论提供一种可能的框架. 相似文献
7.
8.
The paper presents experimental data on flow in the vicinity of a sudden elevation of channel bottom (step). The range of external flow parameters is considered for the case where the step generates waves. A distinguishing feature of these waves is that they are formed in transition from subcritical to supercritical flow. It is shown that there is a range of external parameters in which the depth at the channel exit, the depth above the step, and the distance from the step to the first wave trough depend exclusively on flow discharge. 相似文献
9.
为了反映近岸区域实际存在的多孔介质海底效应,并且考虑到波浪在刚性海底上传播模型的
最新研究进展,运用Green第二恒等式建立了波浪在非平整、多孔介质海底上传播的复合方
程. 假设水深和多孔介质海底层厚度均由两种分量组成:慢变分量,其水平变化的长度尺度大于
表面波的波长;快变分量,其水平变化的长度尺度与表面波的波长等阶,但其振幅小于表面
波的振幅. 另外,多孔介质层下部边界的快变分量比水深的快变分量小1个量级.
针对水体层和多孔介质层,选择Green第二恒等式方法给出了波浪传播和渗透的复合方程,
它在交接面上满足压力和垂直渗透速度的连续性条件,可充分考虑波数变化的一般连续性,
并包含了某些著名的扩展型缓坡方程. 相似文献
10.
I. V. Sturova 《Journal of Applied Mechanics and Technical Physics》2005,46(1):55-61
The behavior of waves generated by periodic pressure on the free surface is considered within the linear shallow-water theory. The fluid depth is a piecewise-constant function, which implies the presence of a finite-size bottom trench or elevation. For an arbitrary shape of bottom unevenness, the solution of the problem reduces to a system of integral boundary equations. Manifestation of wave-guiding properties of bottom unevenness is illustrated by an example of an extended rectangular elevation.Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 1, pp. 70–77, January–February, 2005. 相似文献