Generalized Fluid Models of the Braginskii Type

Several generalizations of the well-known fluid model Braginskii (Rev. Plasma Phys., 1965) are considered. We use Landau collisional operator and moment method Grad. focus on 21-moment that is analogous to model, we also consider a 22-moment model. Both models formulated for general multi-species plasmas with arbitrary masses temperatures, where all moments described by their evolution equations. The contains two "heat flux vectors" (3rd 5th-order moments) "viscosity-tensors" (2nd 4th-order moments). then obtained as particular case one ion-electron plasma similar de-coupled heat fluxes viscosity-tensors expressed in quasi-static approximation. provide numerical values fully analytic form (together 4th For plasmas, makes calculation transport coefficients straightforward. Formulation (instead Hermite suitable implementation into existing codes. It emphasized it approximation which some divergent weakly-collisional regime. Importantly, show coupled even linear approximation, contracted (scalar) perturbations moment, accounted modify energy exchange rates. several Appendices, can be useful guide deriving