This paper presents the results of preliminary numerical and experimental studies concerning the sealing performance of static seals (gaskets) with geometrically designed sealing surface microstructures. The concept of the microstructure, inspired by the operating principle of Tesla’s one-way valve, relies on the generation of localized flow circulation within the microchannels formed between the contact surfaces, which increases flow resistance and reduces leakage. CFD simulations were performed to assess the influence of the geometric parameters of the microstructure on the leakage rate. The numerical calculations demonstrated that introducing microstructures into the gap formed between the contact interfaces can significantly reduce leakage, with the most critical geometric parameters being the gap width between the microprotrusions, their packing density, and their height. Experimental studies confirmed the higher sealing performance of structured gaskets compared to quasi-smooth gaskets, particularly at lower contact pressures. An analysis of the effective contact surface revealed that the improvement in tightness is a result of both the local intensification of the contact pressure and the flow effects induced by the microprotrusions. The results obtained confirm that an appropriately designed surface microstructure can substantially enhance the sealing performance of flange-bolted joints, even under relatively low clamping loads.

This article describes an innovative thermal insulation barrier in the form of a sandwich panel manufactured using 3D FDM printing technology. The internal structure (core structure) of the barrier is based on the Kelvin foam model. This paper presents the influence of the parameters (the height h and the porosity P of a single core cell) of the barrier on its properties (thermal conductivity, thermal resistance, compressive strength, and quasi-static indentation strength). The dominant influence of the porosity of the structure on the determined physical properties of the fabricated samples was demonstrated. The best insulation results were obtained for single-layer composites with a cell height of 4 mm and a porosity of 90%, where the thermal conductivity coefficient was 0.038 W/(m·K) and the thermal resistance 0.537 (m²·K)/W. In contrast, the best compressive strength properties were obtained for the 50% porosity samples and amounted to about 350 MPa, while the moduli for the 90% porosity samples were 14 times lower and amounted to about 26 MPa. The porosity (P) of the composite structure also had a significant effect on the punch shear strength of the samples produced, and the values obtained for the 90% porosity samples did not exceed 1 MPa. In conclusion, the test showed that the resulting 3D cellular composites offer an innovative and environmentally friendly approach to thermal insulation.

The article presents a review of the current state of knowledge on the effect of surface characteristics on contact conditions and leakage in sealed joints with metal gaskets. The sealing mechanism is discussed, in which joint tightness is governed primarily by the deformation of microscale surface irregularities, the increase in the real contact area, and the disruption of the continuity of microgaps forming flow channels. Particular attention is given to the influence of contact geometry and surface topography on the leakage rate. The paper summarizes selected experimental studies on metal gaskets and discusses approaches to modeling the contact of rough surfaces and leakage at their interface. Taken together, the reviewed evidence indicates that reliable prediction of tightness requires simultaneous consideration of contact mechanics, material properties, loading conditions, and the surface geometric structure. The review identifies promising directions for the further development of contact and leakage models. The importance of modeling and the deliberate design of sealing and mating surfaces for improving joint tightness and reducing fluid losses and fugitive emissions is also highlighted.