A paper presents analysis of dynamic similarity between full-scale wind turbines tower-nacelle system and its laboratory model. As a reference real-world structure, Vensys 82 wind turbine was assumed. Complete and partial similarity criteria were both introduced. Considering laboratory model to be equipped with tuned mass damper horizontally arranged at the top, partial similarity of one pair of points (tower tips) motions will be satisfactory. On the basis of similarity conditions, laboratory model parameters were determined so that data acquired for the model may be referred to real-world structure.

Abstract. The study is focused on the energy balance in self-powered vibration reduction system with a linear magnetorheological (MR) damper. The mathematical model of the vibration reduction system is outlined and numerical simulation data are provided. The model involves the mechanical and electrical sub-systems of the electromagnetic generator and an MR damper. For the purpose of the numerical simulations, the parameters of the model were identified through experiments. The objective of the simulations was to establish the energy balance of the system. Energy fluxes associated with energy inputs and outputs as well as a rate of change of inertial energy were determined.

The paper presents an active vibration control system based on low dynamic stiness of suspension. Using a simple two degrees-of-freedom system a few basic concepts of lowering suspension dynamic stiness are presented. Through reducing the dynamic component of force between the protected subsystem and remaining part of the system, considerable vibration suppression is achieved. Linear and nonlinear algorithms are proposed. In the case of nonlinear control algorithm, the sucient link between the protected subsystem and the remaining part of the system necessary to change the position of the protected subsystem is maintained. Experiments described in the paper cover two dierent cases. In the rst case, the suspension operated as the passive suspension, while in the second case, the active reduction system was included. The results are presented graphically.

A design study, named $${\text {ESS}}\nu {\text {SB}}$$ ESS ν SB for European Spallation Source neutrino Super Beam, has been carried out during the years 2018–2022 of how the 5 MW proton linear accelerator of the European Spallation Source under construction in Lund, Sweden, can be used to produce the world’s most intense long-baseline neutrino beam. The high beam intensity will allow for measuring the neutrino oscillations near the second oscillation maximum at which the CP violation signal is close to three times higher than at the first maximum, where other experiments measure. This will enable CP violation discovery in the leptonic sector for a wider range of values of the CP violating phase $$\delta _{{\mathrm{CP}}}$$ δ CP and, in particular, a higher precision measurement of $$\delta _{{\mathrm{CP}}}$$ δ CP . The present Conceptual Design Report describes the results of the design study of the required upgrade of the ESS linac, of the accumulator ring used to compress the linac pulses from 2.86 ms to 1.2 μs, and of the target station, where the 5 MW proton beam is used to produce the intense neutrino beam. It also presents the design of the near detector, which is used to monitor the neutrino beam as well as to measure neutrino cross sections, and of the large underground far detector located 360 km from ESS, where the magnitude of the oscillation appearance of $$\nu _{e }$$ ν e from $$\nu _{\mu }$$ ν μ is measured. The physics performance of the $${\text {ESS}}\nu {\text {SB}}$$ ESS ν SB research facility has been evaluated demonstrating that after 10 years of data-taking, leptonic CP violation can be detected with more than 5 standard deviation significance over 70% of the range of values that the CP violation phase angle $$\delta _{{\mathrm{CP}}}$$ δ CP can take and that $$\delta _{{\mathrm{CP}}}$$ δ CP can be measured with a standard error less than 8° irrespective of the measured value of $$\delta _{{\mathrm{CP}}}$$ δ CP . These results demonstrate the uniquely high physics performance of the proposed $${\text {ESS}}\nu {\text {SB}}$$ ESS ν SB research facility.

In the present study a sandwich plate, of rectangular form, with magnetorheological (MR) fluid core is investigated. The plate consists of two outer layers made of aluminium and an MR fluid layer in between. The plate edges are clamped. It was assumed that the aluminium layers are pure elastic. The energy is dissipated in MR fluid layer. Additional assumptions concerning displacements, deformations and stresses are introduced in calculations. The active segment of MR fluid layer is placed in various parts of plate. The optimal positions of active segment for selected modes of vibration are determined.