  Bulk viscosity has been intrinsically existing in the observational cosmos
evolution with various effects for different cosmological evolution stages
endowed with complicated cosmic media. Normally in the idealized "standard
cosmology" the physical viscosity effect is often negligent in some extent by
assumptions, except for galaxies formation and evolution or the like
astrophysics phenomena. Actually we have not fully understood the physical
origin and effects of cosmic viscosity, including its functions for the
universe evolution in reality. In this present article we extend the concept of
temperature-dependent viscosity from classical statistical physics to
observational cosmology, especially we examine the cosmological effects with
possibility of the existence for two kinds of viscosity forms, which are
described by the Chapman's relation and Sutherland's formula respectively. By
considering that a modification of standard model with viscosity named as
$\Lambda$CDM-V model is constructed, which is supported by data fitting. In
addition to the enhancement to cosmic age value, the $\Lambda$CDM-V model
possesses other two pleasing features: the prediction about the
no-rip/singularity future and the mechanism of smooth transition from imperfect
cosmological models to perfect ones.
