Vortical structures in turbulent buoynat plumes*

Turbulent buoyant plumes are an important phenomenon

to energy transfer and scalar transport

in natural and engineering systems.

We study the statistical stationary state of turbulent fluctuations

in buoyant plumes

using large eddy simulations.

The plume is generated from a heat source

and sustained by buoyancy and entrainment.

Scaling laws are proposed

for various turbulent properties

evolving across the plume.

Budget analysis identifies the leading mechanisms

for the transport of those turbulent properties.

Furthermore,

the probability distribution function

reveals some other details regarding

the characteristics of vorticity.

Near the source,

vorticity is mainly aligned with transverse direction

and return-to isotropy is observed downstream.

Within the plume,

the competition of strain and rotation is compared

and the corresponding alignment of vorticity is analyzed.

Finally,

based on the change of the plume characteristics,

plume structure is categorized into different regions.