Significance of turbulent kinetic energy in sensible thermal energy storage
Answers
In fluid dynamics, turbulence kinetic energy (TKE) is the mean kinetic energy per unit mass associated with eddies in turbulent flow. Physically, the turbulence kinetic energy is characterised by measured root-mean-square (RMS) velocity fluctuations. In Reynolds-averaged Navier Stokes equations, the turbulence kinetic energy can be calculated based on the closure method, i.e. a turbulence model.
TKE can be produced by fluid shear, friction or buoyancy, or through external forcing at low-frequency eddy scales(integral scale). Turbulence kinetic energy is then transferred down the turbulence energy cascade, and is dissipated by viscous forces at the Kolmogorov scale. This process of production, transport and dissipation can be expressed as:
Dk
/
Dt
is the mean-flow material derivative of TKE;
∇ · T′ is the turbulence transport of TKE;
P is the production of TKE, and
ε is the TKE dissipation.