The upcoming hypersonic technologies pose a difficult task for air navigation systems. The article presents a designed model of elastic interaction of penetrating acoustic radiation with flat isotropic suspension elements of an inertial navigation sensor in the operational conditions of hypersonic flight. It has been shown that the acoustic transparency effect in the form of a spatial-frequency resonance becomes possible with simultaneous manifestation of the wave coincidence condition in the acoustic field and equality of the natural oscillation frequency of a finite-size plate and a forced oscillation frequency of an infinite plate. The effect can lead to additional measurement errors of the navigation system. Using the model, the worst and best case suspension oscillation frequencies can be determined, which will help during the design of a navigation system.

The paper is concerned with an analysis of behaviour of the cableway. On the basis of design data and results of adequate experiments, a physical model of cableway was formulated. The static of cableway was developed assuming a full nonlinear model based on elastic catenary curve. The tension of the rope and the reactive forces between the rope and the supports were calculated. Assuming various loadings of the rope, the relation between the tension in bottom and upper stations and the length of the rope was determined. The model describing the motion of the system is linear. Finite elements were used to formulate the model. Two methods of accelerating the system were investigated.

The following work gives the details of the modelling, simulation, and testing of a small portable gravitational water vortex (GWV) based power plant. The gravitation water vortex is an ideal source of renewable energy for rural areas that have a small body of flowing water. For this purpose, we have selected a small size for the vortex chamber that enables it to form a vortex with limited amounts of water. The paper gives the details of the simulation of the GWV in COMSOL FEA software and the parameters that were chosen for optimization. These parameters were the height of the vortex chamber, the number of blades, the length of the blades, and the tilt angle of the blades. These parameters were systematically varied step by step, to observe their effect on the speed of the rotor. The results of the parametric sweep that was performed on all the parameters are also presented. Based on the simulation results an optimal set of parameters was chosen for the physical implementation of the GWV. The paper also goes into the details of the construction of the physical GWV, the experimental setup that was devised for the testing and verification of the simulation results.