Prethodno priopćenje

A CURVATURE EFFECT ON THE CRITICAL RICHARDSON NUMBER

Branko Grisogono ; Department of meteorology Uppsala University, Box 516 S-75120 Uppsala, Sweden

Sažetak

Transitions from laminar to turbulent flow associated with a critical level in the stratified shear flow are related to the critical (gradient) Richardson number, Ric, the minimum value of which is Ric ≈ 1/4. Based on the linear theory and a modified Taylor-Goldstein equation, here it is plausibly shown that Ric may slightly
vary from this value if the mean wind speed profile contains a small curvature (parameterized here) around the critical level. The modified Ric that depends on the dimensionless curvature α ≡ (U’’ζ/U’) is
Ric(α) = (1 + α/2)[α + (1 + α/2)/4].

Ključne riječi

Richardson number; critical level; Taylor-Goldstein equation; parameterization

Hrčak ID:

68043

URI

https://hrcak.srce.hr/68043

Datum izdavanja:

15.12.1994.

Posjeta: 881 *