Physical Significance of k-epsilon model constants
 

Please kindly explain: what is the physical significance of the k-epsilon model constants? For instance the model constants in Standard K-epsilon are:

Cμ = 0.09, C1-Ɛ = 1.44, C2-Ɛ = 1.92, TKE Prandtl no., = 1.0, TDR Prandtl no. = 1.3

Of what physical relevance are they? In practice, what do they represent?