In this chapter1 we focus our attention on one of the possible improvements
of the classical model of the viscous fluid. The goal is to overcome the basic
shortcoming of the classical model: the contradiction with the causality principle. To
solve the problem we take into account an observer, consider him as an element of the
model and build the model of the fluid from his unique point of view. This approach
appears to be rather general and allows application in related areas such as heat and
mass transfer, signal propagation in a moving continuum and others.
Keywords: Body configuration, Body force, Causality principle, Conservation
law, Contact force, Metric tensor, Observer, Signal speed, Space-time continuum,
Thermodynamics, Total energy, Viscous fluid model, World-line.
