In this work, 3D models in classic configuration of Bach and Benesh rotor type, as well as models with modified blade pattern geometry were analyzed from the air circulation point of view inside the rotor enclosure in order to identify the operating parameters differences according to rotor geometric modified configuration. Constructive design aspects are presented, as well as results obtained from the virtual model analysis in terms of circulation velocity and pressure values which enhance rotor operation related to torque and power coefficients. The rotors design pattern is made according to previous results obtained by different researchers who have performed numerical analysis on virtual models and tests on the experimental rotor models using the wind tunnel. The constructive solutions are describing two-bladed rotor models, in four new designed constructive variants and analyzed using ANSYS CFX. The air velocity specific values, static and total pressure recorded at the rotor blade level are highlighted, that influence the obtaining of rotor shaft torque and power. Also torque coefficient (CT) and power coefficient (CP) values according with specific values of tip speed ratio (TSR) are presented for each analyzed case. The analysis results show higher power coefficient values for analyzed Bach V2 and Benesh V2 rotor modified models compared to the classic Bach and Benesh models for 0.3 TSR of 0.11–012 CP, 0.4 TSR of 0.18 CP (Benesh V2 model) and 0.27 CP at 0.6 TSR (Bach V2). The resulted values confirm that Benesh V2 model offers higher CP up to 5% at TSR 0.3, 2% at TSR 0.6 and 3% at TSR 0.4 compared to the Benesh classical model. The Bach V2 model offers 4% higher CP compared to the classic Bach model at TSR 0.6. Based on these results it is intended the further analytical and experimental research in order to obtain optimal rotor pattern.

Wind force is a considerable resource on the basis of which a significant amount of energy can be obtained, necessary in an agricultural farm that is not connected to the energy distribution network. For this case a low capacity wind turbine can be used as a practical solution, which has the possibility to supply the necessary amount of energy within the farm. The solution is represented by the use of a vertical axis wind turbine with that has component an improved SAVONIUS type rotor. Constructive and energy performance aspects of this rotor type are presented based on studies conducted by various researchers over time, being presented the optimal model to be used in the agricultural farm for energy generation. Values of the energetic performances obtained from analytical but also experimental studies of the optimized models of the turbine rotor with vertical axis that works on the Savonius principle are presented. It is also emphasized the advantage of using this solution in terms of protecting the environment by avoiding fuel burns to obtain the energy needed on the agricultural farm.

The construction industry has seen a remarkable development in recent decades, making it possible to build infrastructure elements capable of withstanding considerable demands on traffic, wind or seismic actions. These achievements have been made due to the solutions used for isolation against dynamic actions that may require the structure at a given time. In order to ensure the protection of construction structures against seismic actions, many constructive solutions have been developed which can be mounted inside the resistance structure. These are mechanical systems used for isolation and seismic energy dissipation, which by operation are able to modify structural behaviour at earthquake. A hybrid seismic isolation model is described which is classified under the building base isolation systems category. This system consists of concave roller elements in combination with elastomeric shock absorbing elements. An experimental model has been developed and analysed, and the results are presented in terms of accelerations in time and frequency at the level of the structural elements at which the recordings are made during excitation simulating the action of a seismic event. The isolation system is used on the low model of a bridge or viaduct structure. Analyses are made for different models of insulation system layout at the isolated structure and distinct cases regarding the construction of the component parts regarding the rolling elements in contact with the concave surface. The results are presented for each structural element in part describing the registered values of acceleration due to the excitation on the supporting pier and the superstructure over the three main directions of movement according to the constructive type of the rolling elements that are included in the isolating system. Experimental analysis was performed on a small-scale system under laboratory conditions, based on a set of simplified assumptions. The advantage of this approach is supported by multiple possibilities of simulation of real dynamic loading situations, static and dynamic loading states, structural and functional schemes and functional configurations of the supporting and isolation systems against dynamic actions. Thus, the transfer of experimental results from reduced models to real systems through mathematical and computer models associated with them is ensured by appropriate transfer functions.

The seismic isolation of the construction structures is of particular importance because the optimum stability premises of the structures during the seismic events are ensured. There are different isolation methods but based on the structure base isolation principle, the friction pendulum bearing systems (FPBS) have been used with good results in equipping new structures and also in rehabilitating of the old buildings that had to be consolidated. The double surface friction Pendulum (DSFP) bearing is an improved version of the well-known single concave friction pendulum bearing (FPBS). The principal benefit of the DSFP bearing is represented by its capacity to accommodate substantially larger displacements compared to a traditional FPBS of identical plan dimensions. Moreover, there is the capability to use sliding surfaces with different radius of curvature and friction coefficients, offering the designer greater flexibility to optimize the protective system performance. Through these systems good seismic isolation results are achieved for the building structures where mounted interposed between the foundation and the superstructure realizing the disconnection between the two structural elements. The disconnection is important because the insulated structure vibration period is modified in the sense of its significant increase, also with the increase of structure lateral flexibility, ultimately reducing the ground acceleration and avoiding the efforts vertical transmission to the isolated structure upper levels. The double surface friction pendulum system ensures an important modification of the isolated structure behavior materialized through the seismic response mitigation. This paper describes the double surface friction bearing (DSFP) constructive details with operation principles and also presents some numerical analysis results related to force–displacement relation considering different values of curvature radius and friction coefficients of the two friction surfaces used

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