This paper presents results of experimental investigations and numerical simulations of a vertical-axis H-type wind turbine, considering the influence of propeller blade pitch angle on turbine characteristics. An innovative airfoil profile based on a modified symmetric NACA0015 airfoil profile was used as the designed blade profile, which was tested in a wind tunnel over a range of Reynolds numbers from 50,000 to 300,000. The phenomenon of angle-of-attack variation and the resulting forces acting on the blades, particularly in the horizontal configuration and vertical axis of rotation, were discussed. Series of experiments were conducted on a 1:1 scale four-bladed turbine model in the wind tunnel to determine the characteristics, specifically the power coefficient distribution over the tip speed ratio for various Reynolds numbers and blade pitch angles. Subsequently, the turbine was modeled using Qblade software, and a series of calculations were performed under the same conditions. The numerical results were validated with the experimental data.

This paper presents a method for preparing a pressure sensor that is insensitive to acceleration along with experimental evidence of its efficacy in aerodynamic analysis. A literature review and preliminary studies revealed the undesirable effect of acceleration on sensors that are located on moving elements, as evidenced by deviations from actual pressure values for piezoresistive pressure sensors that are made using MEMS technology. To address this, the authors developed a double-membrane sensor geometry that eliminated this imperfection; a method of implementing two solo pressure sensors as a new geometry-designed sensor was also proposed. Experimental tests of this suggested solution were conducted; these measurements are presented here. The results indicated that this new sensor concept could be used to measure the dynamic pressures of rotating and moving objects in order to obtain measurement results that are more reliable and closer to the true values that are derived from aerodynamic analyses. The published results confirm the reliability of the proposed device.

This article presents an experimental approach to fatigue testing of cableway gondolas, carried out in accordance with the EN 13796-3 standard. Due to the limitations of the aforementioned regulations and the lack of clarity in their content, when designing and conducting fatigue tests of gondolas, there is a need to find solutions that meet the normative requirements, while ensuring the cost-effectiveness of the tests. The work presents the method of loading, receiving the degrees of freedom, the methodology of gondola strength verification and additional suggestions allowing for the satisfactory preparation of a plan of fatigue tests and their implementation. The paper shows problems and ways to solve it, what may occur during cableway gondolas fatigue test design. In addition, the work contains an extensive description and methodology for conducting research verifying the elastic and permanent deformation of the structure, using digital image correlation (DIC). The results obtained by using this method make it possible to unambiguously determine the degree of structure deformation while maintaining high accuracy and repeatability of measurements at many points of the structure. Following the presented tests, it was possible to correctly carry out fatigue tests of the nacelle in a satisfactory time (about 8 weeks), perform 5 million load cycles and verify the integrity of the structure. The presented results show the effectiveness of the adopted design assumptions and indicate the process that guarantees the correctness of the conducted fatigue tests. The prepared study may be the basis for further full-scale fatigue tests. The research object is a 6-seater gondola designed by TRANSSYSTEM S.A.

Experimental studies of a pneumatic drive system were carried out with the ap-plied element for the concurrent movement of two pneumatic drives. The main aim of these experiments was to obtain the results of specific measurements of displacements of two piston rods of pneumatic drives in relation...