DEFINING OF THE TEMPERATURE OF THERMAL DAMAGE OF THE HEAT-STRESSED SURFACES OF THE ENGINE IN THE APPROXIMATION OF «RUNNING WAVE» WITH VARIDLE VELOCITY

Abstract

It is well known that, in a rigorous formulation, the problem of non-stationary convective heat exchange must be formulated and solved as an adjoint problem with boundary conditions of the fourth kind. Such a formulation assumes the solution of an external hydrodynamic problem and the conjugation of its results with the solution of an internal heat conduction problem.

In the approximation of the "traveling wave", the authors determined the limiting values ​​of the temperature at which thermal damage occurs (microcracks - "web") of the heat exchange surfaces of the internal combustion engine.

The article states that at t = 1200. . .1800 C the temperature of the piston head reaches the limit for this metal value of 750 K, which increases the risk of its thermal damage. In case of force majeure (emergency loading of the engine or its overload when swimming in ice) it is necessary to use removable heads of heat-resistant steel pistons.