本文采用直接数值模拟方法,在具有平均标量梯度的各向同性湍流中,研究被动标量的小尺度结构特性及其与湍流场中应变与涡量的关系.对欧拉统计量及拉格朗日统计量的统计表明:标量耗散的形成主要是由于标量梯度同流场的应变张量压缩主轴耦合的结果,而涡量对标量梯度的形成只有较弱的影响,然而它可以间接影响大强度标量耗散的产生.强标量耗散的细微片状结构的形成时间尺度大约为10倍Kolmogrov时间尺度;在形成强标量梯度的细微片状结构过程中,应变强度随标量梯度同步增大,而涡量则先减小后增大,并在5倍Kolmogorov时间尺度时达到最大.
参考文献
[1] | Warhaft Z. .Passive scalars in turbulent flows [Review][J].Annual Review of Fluid Mechanics,2000(0):203-240. |
[2] | Veynante D;Vervisch L.Turbulent Combustion Modeling[J].Progress in Energy and Combustion Science,2002(28):193-266. |
[3] | Ruetsch G R;Maxey M R .Small-Scale Features of Vorticity and Passive Scalar Fields in Homogeneous Isotropic Turbulence[J].Physics of Fluids,1991,A3:1587-1597. |
[4] | Ruetsch G R;Maxey M R .The Evolution of Small-Scale Structures in Homogeneous Isotropic Turbulence[J].Physics of Fluids,1992,A4:2747-2760. |
[5] | Vedula P.;Fox RO.;Yeung PK. .Dynamics of scalar dissipation in isotropic turbulence: a numerical and modelling study[J].Journal of Fluid Mechanics,2001(0):29-60. |
[6] | Brethouwer G.;Hunt JCR.;Nieuwstadt FTM. .Micro-structure and Lagrangian statistics of the scalar field with a mean gradient in isotropic turbulence[J].Journal of Fluid Mechanics,2003(0):193-225. |
[7] | Eswaran V;Pope S B .Direct Numerical Simulations of the Turbulent Mixing of a Passive Scalar[J].Physics of Fluids,31(03):506-520. |
[8] | Canuto C;Hussaini M Y;Quarteroni A.Spectral Methods in Fluid Dynamics[M].Springer and Verlag Press:New York,1988 |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%