現象論に基づく自己相似な円形噴流の計算

抄録

This paper presents a phenomenological analysis of a circular jet for an incompressible fluid in the self-preserving flow region. In the eddy viscosity expression: νT∞|υ||ι|, where υ means turbulent velocity component normal to the jet axis and l a kind of Inixing length, |υ| is assumed to be proportional to √υυ²and |l| to the integral scale of turbulence Λg. Expressing them approximately by simple functions so as to simulate the measurements, mean velocity distributions are satisfactorily calculated.
In applying the same approach to an axisymmetric far wake flow, simple expressions for the mean velocity defect are obtained, which prooved to be good empirical formulae for the mean velocity distributions of a circular jet.
Considerations are also made about the scalar properties like heat and concentration.