The Development of Thermals from Rest

摘要: Abstract Conventional techniques for releasing a thermal in laboratory experiments induce enough initial motion to affect seriously the thermal's subsequent evolution. We have invented mechanism thermals from very close state of rest. This allows examination transient behavior previous development self-similarity. A starting rest exhibits much smaller entrainment rate than self-similar distance its point at least six diameters. Since we find that typically penetrate four diameters or less stably stratified environment, this has potentially great significance atmospheric convection. Numerical simulations using an axisymmetric, two fluid model aid interpretation these results.