This work is inspired by the current European policies that aim to reduce plastic waste. This is especially true of the packaging industry. The biocomposites developed in the work belong to the group of environmentally friendly plastics that can reduce the increasing costs of environmental fees in the future. Three types of short fibers (flax, hemp and wood) with a length of 1 mm each were selected as fillers (30% mass content in PHBV). The biocomposites were extruded and then processed by the injection molding process with the same technical parameters. The samples obtained in this way were tested for mechanical properties and quality of the molded pieces. A significant improvement of some mechanical properties of biocomposites containing hemp and flax fibers and quality of molded pieces was obtained in comparison with pure PHBV. Only in the case of wood–PHBV biocomposites was no significant improvement of properties obtained compared to biocomposites with other fillers used in this research. The use of natural fibers, in particular hemp fibers as a filler in the PHBV matrix, in most cases has a positive effect on improving the mechanical properties and quality of molded pieces. In addition, it should be remembered that the obtained biocomposites are of natural origin and are fully biodegradable, which are interesting and desirable properties that are a part of the current trend regarding the production and commercialization of modern biomaterials.

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 an attempt to determine the dynamic properties of a measuring system based on total pressure measurement with the use of a Pitot tube and a semiconductor pressure transducer. The presented research uses computed fluid dynamics (CFD) simulation and real data from the pressure measurement system for determination of the dynamical model of the Pitot tube with the transducer. An identification algorithm is applied to the data from the simulation, and the model in the form of a transfer function is an identification result. The oscillatory behavior is detected, and this result is confirmed by frequency analysis of the recorded pressure measurements. One of the resonant frequencies is the same in both experiments, but the second is slightly different. The identified dynamical models permit the possibility to predict deviations caused by dynamics and to select the appropriate tube for a particular experiment.

This paper aims to describe an idea for an integration process and tests of flight parameters measurement system, which supports infrared thermography (IRT) boundary layer mapping. The study of flow changes in the boundary layer with the use of IRT requires registration of the thermal images of the selected area of a wing or the fuselage, as well as synchronous recording of flight parameters. These tasks were realized by the supplementary measurement system mounted on the PW-6U glider. Two examples of the determination of the laminar-turbulent transition areas on the left wing of a PW-6U glider are also presented in the paper. Optical methods can be used in several research areas, for example, aerodynamics and strength analysis. For instance, the measurement of the infrared radiation from surfaces with the use of IRT can be used for the measurement, with high accuracy, of surface temperature distribution. Moreover, the thermography is used for the analysis of the boundary layer. Performed in-flight experiments confirm the possibility of practical usage of the IRT method even on the board of a glider. The use of optical methods will, in many cases, be less expensive than assembly of an additional measurement and data acquisition systems. Implementation of optical methods for industrial purposes has many advantages, and, hence, they will probably become very common in the future. The study introduces advanced measurement and visualization techniques in general aviation.

The article presents an aerodynamic concept of UAV in the gyrodyne configuration, as a more efficient one than the currently used UAV airframe configuration applied for monitoring tasks of power lines and railway infrastructure. A sample task which is realised by conceptual gyrodyne based on monitoring aerial power lines was characterised and described. The assumed idea of UAV was shown in comparison to the currently used aircraft configuration presented in the introduction. Referring to momentum theory, hover efficiency of the multicopter and the helicopter was evaluated. In relation to the helicopter, an initial draft of the airframe conception accompanied by a description of advantages of the gyrodyne configuration was exposed. Problems related to the gyrodyne configuration were emphasised in the summary.

Presented article shows the problem of finding mathematical model of the dynamics of the displacement of the pressure wave inside the probes tube.