That model based on this quantity was also modified using five model constants and three "damping functions" by Launder and Sharma to be more accurate near walls.
This quantity is the conceptual basis for a model which can be made more accurate by adding an extra source term in the Yap correction. That model based on this quantity can be extended to a so-called "four equation model" by adding two dependent variables denoted zeta and f. That model based on this quantity was also modified using five model constants and three "damping functions" by Launder and Sharma to be more accurate near walls. This quantity is proportional to k squared over epsilon, or equal to k over omega, in the k-epsilon and k-omega models, respectively. Boussinesq dealt with closure problem for the RANS (spell it out) equations by introducing this quantity, which relates the mean strain rate tensor to the Reynolds stress and conceptually acts as a diffusion coefficient for momentum. For 10 points, name this quantity which describes the energy transfer caused by circular fluid currents in a turbulent flow.
This quantity is the conceptual basis for a model which can be made more accurate by adding an extra source term in the Yap correction.
eddy viscosity [or eddy diffusivity; prompt on viscosity or kinematic viscosity or turbulent viscosity; prompt on diffusivity or momentum diffusivity]