International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

For various canonical forms (plane, cylinder, ball, etc.), a generalized mathematical model (MM) of a nonlinear steady-state process of molecular heat transfer (or moisture diffusion) through enclosing structures (ES) is proposed, taking into account infiltration or exfiltration of a vapor-air (gas) mixture and the presence of various internal or surface positive (moisture condensation) or negative (evaporation of moisture) of heat sources (HS). The mathematical formalization of the posed boundary value problem (BVP) of transfer and its general solution are given, on the basis of which, under various specified conditions of unambiguity, solutions of specific physical processes with constant or variable thermophysical characteristics and HS are constructed and analyzed. For large-scale transitions, the short-circuit problem is posed and solved under various boundary conditions (BVC), written in a criterion form as dependences of the dimensionless temperature T(R-, Pe, Po) on the dimensionless thermal resistance (R-) of the heat exchange criteria for the similarity of Pecle (Pe) and Pomerantsev (Po).

The current product on the market offers a wide range of diverse profiles for producing windows that are made of different materials, width and order of grills depending on the profile. Within the framework of this research the windows with same dimensions shall be elaborated, those which are made of the same production capacity and use the same fittings but different types of PVC profiles. The aim is to prove what kind of influence the used profile has over the final quality of the product. For this research, two groups and six subgroups will be tested. In each subgroup, one tests five windows made of the same profile. The groups are divided according to the used fittings. The testing of the quality shall be conducted in accordance with the European norms EN 1026:2016 (Windows and doors – Air permeability – Test method), EN 1027:2016 (Windows and doors – Water tightness – Test method), EN 12211:2016 (Windows and doors – Resistance to wind load – Test method).