Über turbulente Bewegungen,die von Temperaturschwankungen hervorgerufen werden – eine kritische Betrachtung zur Boussinesq-Approximation |
| |
| Authors: | G Rüdiger |
| |
| Abstract: | This paper deals with fluctuating motions which are caused by a given stochastical temperature field acting in a gas with gravitation and T¯ = const. It results that the often used BOUSSINESQ approximation much underestimates the horizontal motions in case wide-spread temperature fluctuations occur. For sufficiently large scales the horizontal motion exceeds the vertical ones even in the case of the temperature field fluctuating completely isotropically. Scales of 1000 km and 1 day in the Earth atmosphere lead to the observed value u′horiz/|u′vertic ≈︁ 10. Finally besides the relation between density correlation and pressure correlation we determine the expression for the turbulent mass transport vanishing with the molecular viscosity. |
| |
| Keywords: | |
|
|
