The turbulence time and length scales representing the energy containing eddies are by Tt = CtT k/ε and lt, = Ctl k32/ε, respectively, while the Kolmogorov time and length scales representing the energy dissipative eddies are expressed by Tk = CkT (υ/ε)1/2 and lk = Ckl (υ3/ε)1/4, respectively. The available DNS data for fully developed channel flows with and without wall injection / suction are used to determine the coefficients. It is found that, with the typical values of CtT = Ctl = 1 which are usually adopted in the turbulence study, CkT = 2 and Ckl = 3. However, this set of coefficients lead to underprediction of the thickness of viscous sublayer yVSL+. By relaxing the usual assumption of CtT = Ctl = 1, a new set of coefficients: CtT = Ctl = 0.8, CkT = 4, and Ckl = 9 is suggested. The yVSL+ calculated with this set of coefficients becomes more physically reasonable.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanical Engineering
- Applied Mathematics