Qualitative aspects of Viscous What is aⅴ iscous flow? a flow where the effects of VIscoSI thermal conduction and mass diffusion are important (in gas with gradients in chemical species, and not concerned here)Qualitative aspects of viscous Flow • What is a viscous flow? • A flow where the effects of • viscosity, • thermal conduction • and mass diffusion are important. • (in gas with gradients in chemical species,and not concerned here)