It is known that nano- and micromechanics require new approaches to right describing of surface-like phenomena which lead to an enhanced energy conversion. In this work, a general form of surface forces that consist of a contribution from both the friction and mobility components has been extended to collect the effects of bulk and surface motion of a fluid. Quite similar impact can be observed for a solid-fluid mixture, where the principle of effective stress for this new type of approach should be considered from the very beginning. The second motivation of our work is to present the multiscale domain of fluid-solid interaction which describes some “emergence effects” for materials with especially high volumetric surface densities.

Glass materials are constantly the base of life the majority of society. A lot of us, every morning brew a cup of tea or coffee in his favourite cup or look out glass pane in order to define the weather outside. Examples can be multiplied and multiplied. On account the role of glass materials, in most people life, has been decided to choice a glass material as a base to perform thermal FSI analysis. However the analysis would be nothing without calculative model. It is well known that there are various strength hypothesis, which treat of material strength dependency on reduced tension. In most cases, to the issue which is related to reduced tensions appointment which appear in analysed material, the Huber-Mises-Hencky hypothesis is used, but it is difficult to model glass material by this hypothesis. It happens because of specific properties of glass, which is amorphous body. And here, with help occurs the W.Burzynski, Huber’s student. Burzynski proposed the following reduced tension definition: ${\Phi }_f+\eta (p)\cdot {\Phi }_v=K$ , from which the Burzynski material effort is calculated:${\sigma }_B=\frac{1}{2k}\cdot \left[-(k-1)\cdot {\sigma }_m+\sqrt{{(k-1)}^2\cdot {\sigma }_m^2+4\cdot k\cdot {\sigma }_{HMH}^2}\right]$ . We reached to the idea, which is the introduction of material properties coefficient k. This parameter describes the relation of compressing strength to the tensile strength. Furthermore, R. Pecherski proposed the Burzynski hypothesis enlargement by Lode’s angle influence, which controls the participation of the energy density of distortion. Finally the Burzynski-Pecherski hypothesis is: ${\tilde{\eta }}_f(\theta ){\varphi }_f+{\tilde{\eta }}_v(p){\varphi }_v=K$ . Where θ describes Lode’s angle. In this work is presented the comparison of aforementioned hypothesis and delimitation the differences in received results stresses values by each one of hypothesis. As example of analysed problem the cold glass cup under nonstationary thermal load (which is simulated by boiled water) is taken under consideration. The analysis consist of flow calculations, bounded with filling the glass cup by hot fluid, import of geometry inner walls temperature values and finally calculation of reduced stresses using both strength hypothesis.

Development of the Thermal-FSI (Fluid Solid Interaction) let to accurate the process of cooling the steam turbine set. It provide to shorter times of maintenance and repairs of the turbine sets. The cooling of the steam turbine which temperature exceeds 500°C can take time of one week. Insulation and housing is taken off when temperature reaches 100°C. In analysis was applied thermal-FSI which takes into account temperature changes between solid material and fluid. In the paper authors propose this way to estimate effort of the turbine structure caused by an intrusion of water into the flow channels.

This paper presents a comprehensive study on the impact of erosion on the flow characteristics through the blade of the last stage of a 900 MW steam turbine. The primary objective is to understand how surface erosion, caused by prolonged steam exposure, affects flow behavior and the overall efficiency of a 900 MW class turbine. The research process began with a 3D scan of the turbine blade, using advanced laser scanning technology to create a detailed geometric model. As one of the longest blades used in steam turbines, it posed both a technical challenge and was an innovative aspect of this study. The resulting 3D model served as the basis for numerical simulations using Computational Fluid Dynamic (CFD) methods, which allowed for the analysis of steam flow over the eroded blade surface. Key flow parameters, including velocity, pressure, and turbulence, were assessed to determine the impact of erosion. The study revealed significant changes in flow characteristics depending on the degree of erosion, providing valuable insights for turbine optimization and maintenance. The novelty of this research lies not only in the use of advanced scanning technologies but also in analyzing one of the longest blades in industrial practice, with findings that could enhance turbine efficiency and inform new erosion risk management strategies.