ІRSTІ 44.31.31                                                                                       №3 (2019г.)

Genbach А.А., Bondartsev D.Yu., Iliev I.K.

Modeling of low-porous capillary-porous coatings with poor thermal conductivity and metal (copper, stainless steel) surfaces (substrate) is studied.
Dynamics of steam bubbles and their thermohydraulic characteristics observed by optical methods of research are described. “Birth” and “death” of steam bubbles proceeded explosively in the centers of generation, which were considered as sources of fatigue cracks. The solution of the problem of thermoelasticity allowed to reveal the influence of specific heat flux and thermal stress of compression and stretching depending on the time of supply and the size of detachable particles at the moment of the limiting state of the system: “porous coating – substrate”. The theory is confirmed by the experimentation received through observation by with the SCS-1M camera. At a short time ~10-2 with heat supply only compression
stresses appear, and then they pass into tensile stresses at the depth of coating. The specific energy of fracture has a pronounced minimum and with the growth of the particle size shifts in the direction of decreasing heat flow.
Keywords: capillary porous coatings, thermoelasticity, compression voltages, tensile stresses, model, heat and power plants.