Investigation of the performance of a hybrid wind turbine Darrieus-Savonius

The constantly rising fossil fuels prices and the different agreements between the industrialized countries for carbon dioxide emissions reduction are driving forward the renewable energy sector development. The wind energy systems are one of the most popular, cost-effective systems in comparison with most of the available renewable energy utilizing systems to date. Due to this fact, the interest and investments in wind energy systems are steadily growing through the last decade. The investment in the wind energy sector for the European Union member states is expected to reach 20 billion euro until 2030. The need of sustainable "green" households and the new European legislation regarding that problem are contributing to the integration of the wind energy systems into the urban areas. According to the above-pointed facts the wind energy sector stands as a major point of interest for further study, development and innovation. The adopted main investigation methods regarding the completion of the thesis set of tasks are as follows: creation of a geometrical model (2D and 3D) for all of the turbine’s investigated designs; computational mesh generation – finite volume method; computational solver setup, software used ANSYS Fluent 14.0; conduction of a numerical modelling over the force interaction between an air flow and rotating wind rotor; development of an methodology for experimental investigation of vertical axis wind turbines; manufacturing of an multifunctional test bench for experimental analysis of wind turbines; evaluation of the accuracy of the experimental measurements over the turbine performance - torque, drag force, rotational speed, wind speed etc

Numerical modelling of an H-type Darrieus wind turbine performance under turbulent wind

This paper presents the force interaction between fluid flow and a rotating H-type Darrieus vertical axis wind turbine. The main goal of this study is to determine the wind rotor’s performance characteristics under turbulent wind: torque M = f (n), normal force FN = f (n), output power P = f (n) and the aerodynamic characteristics CM = f (λ), CN = f (λ), CP = f (λ). The flow passing through the turbine has a complex structure due to the rotation of the rotor. The constantly changing angular position of the turbine’s blades is leading to a variation in the blades angle of attack. This angle can vary from positive to negative values in just a single turbine revolution. The constant fluctuations of the angle of attack are the main factor which leads to the unsteady nature of the flow passing through the turbine. At low tip-speed ratios, the phenomena deep dynamic stall occurs which leads to intensive eddy generation. When the turbine is operating at higher tip-speed ratio the flow is mainly attached to the blades and the effect of the dynamic stall over the turbine performance is from weak to none. The Darrius turbine performance characteristics are obtained through a numerical investigation carried out for several tip-speed ratios. The used CFD technique is based upon the URANS approach for solving the Navier-Stokes equations in combination with the turbulence model k – ω SST. Also, a numerical sensitive study concerning some of the simulation parameters is carried out

Holistic Thermal Energy Modelling for Full Hybrid Electric Vehicles (HEVs)

Full hybrid electric vehicles are usually defined by their capability to drive in a fully electric mode, offering the advantage that they do not produce any emissions at the point of use. This is particularly important in built up areas, where localized emissions in the form of NOx and particulate matter may worsen health issues such as respiratory disease. However, high degrees of electrification also mean that waste heat from the internal combustion engine is often not available for heating the cabin and for maintaining the temperature of the powertrain and emissions control system. If not managed properly, this can result in increased fuel consumption, exhaust emissions, and reduced electric-only range at moderately high or low ambient temperatures negating many of the benefits of the electrification. This paper describes the development of a holistic, modular vehicle model designed for development of an integrated thermal energy management strategy. The developed model utilizes advanced simulation techniques, such as co-simulation, to incorporate a high-fidelity 1D thermo-fluid model, a multi-phase HVAC model, and a multi-zone cabin model within an existing longitudinal powertrain simulation environment. It is shown that the final model is useful of detailed analysis of thermal pathways including energy losses due to powertrain warm-up at various ambient temperatures and after periods of parked time. This enables identification of sources of energy loss and inefficiency over a wide range of environmental conditions. </div

Design development and performance evaluation of ICE exhaust silencer

The noise levels generated by an unmuffled engine exhaust system can be identified as the loudest vehicle noise source. The muffler or silencer is an essential component of the internal combustion engine exhaust system, its main function is to reduce the exhaust-generated noise to an acceptably low level. Its design development is a complex process affecting the engine efficiency and thusfuel consumption, emissions and overall noise generation. This paper focuses on the design development of a muffler for a single cylinder engine application. A 1D GT-Power model of a single valve engine was developed. Additionally, an analytical muffler preliminary design methodology was introduced. The methodology provides guidelines for muffler grade selection, sizing of different components, calculation of back pressure as a function of the exhaust gas flow rate. Two custom mufflers design concepts were developed for the single cylinder engine based on the introduced analytical methodology. Two commercial single cylinder engine muffler designs available from Yanmar and Loncin were considered for the engine performance evaluation simulation. The presented combination of analytical and numerical modelling procedures can reduce the overall length of the muffler development stage by eliminating faulty design concepts and refining the muffler’s performance parameters

Co-Simulation Methods for Holistic Vehicle Design: A Comparison

Vehicle development involves the design and integration of subsystems of different domains to meet performance, efficiency, and emissions targets set during the initial developmental stages. Before a physical prototype of a vehicle or vehicle powertrain is tested, engineers build and test virtual prototypes of the design(s) on multiple stages throughout the development cycle. In addition, controllers and physical prototypes of subsystems are tested under simulated signals before a physical prototype of the vehicle is available. Different departments within an automotive company tend to use different modelling and simulation tools specific to the needs of their specific engineering discipline. While this makes sense considering the development of the said system, subsystem, or component, modern holistic vehicle engineering requires the constituent parts to operate in synergy with one-another in order to ensure vehicle-level optimal performance. Due to the above, integrated simulation of the models developed in different environments is necessary. While a large volume of existing co-simulation related publications aimed towards engineering software developers, user-oriented publications on the characteristics of integration methods are very limited. This paper reviews the current trends in model integration methods applied within the automotive industry. The reviewed model integration methods are evaluated and compared with respect to an array of criteria such as required workflow, software requirements, numerical results, and simulation speed by means of setting up and carrying out simulations on a set of different model integration case studies. The results of this evaluation constitute a comparative analysis of the suitability of each integration method for different automotive design applications. This comparison is aimed towards the end-users of simulation tools, who in the process of setting up a holistic high-level vehicle model, may have to select the most suitable among an array of available model integration techniques, given the application and the set of selection criteria

Modelling and Co-simulation of hybrid vehicles: A thermal management perspective

Thermal management plays a vital role in the modern vehicle design and delivery. It enables the thermal analysis and optimisation of energy distribution to improve performance, increase efficiency and reduce emissions. Due to the complexity of the overall vehicle system, it is necessary to use a combination of simulation tools. Therefore, the co-simulation is at the centre of the design and analysis of electric, hybrid vehicles. For a holistic vehicle simulation to be realized, the simulation environment must support many physical domains. In this paper, a wide variety of system designs for modelling vehicle thermal performance are reviewed, providing an overview of necessary considerations for developing a cost-effective tool to evaluate fuel consumption and emissions across dynamic drive-cycles and under a range of weather conditions. The virtual models reviewed in this paper provide tools for component-level, system-level and control design, analysis, and optimisation. This paper concerns the latest techniques for an overall vehicle model development and software integration of multi-domain subsystems from a thermal management view and discusses the challenges presented for future studies

Numerical modelling of the operation of a two-phase thermosyphon

In the recent years, the interest towards the application of two-phase thermosyphons as an element of heat recovery systems has significantly increased. The application of thermosyphons is steadily gaining popularity in a wide range of industries and energy solutions. In the present study, a 2-D numerical modelling of a two-phase gas/liquid flow and the simultaneously ongoing processes of evaporation and condensation in a thermosyphon is presented. The technique volume of fluid was used for the modelling of the interaction between the liquid and gas phases. The operation of a finned tubes thermosyphon was studied at several typical operating modes. A parametric study over a non-ribbed and finned tubes thermosyphon was carried out. The commercial software ANSYS FLUENT 14.0 was used for the numerical analysis. It was proven that the numerical modelling procedure adequately recreates the ongoing flow, heat and mass transfer processes in the thermosyphon. The numerical result from the phase interaction in the thermosyphon was visualized. Otherwise, such visualization is difficult to achieve when only using empirical models or laboratory experiments. In conclusion, it is shown that numerical modelling is a useful tool for studying and better understanding of the phase changes and heat and mass transfer in a thermosyphon operation

Operational-Investigative Activities of Judicial Authorization: Features of Performance

The scientific article is devoted to the study of issues related to the peculiarities of performing operational-investigative activities of judicial authorization enshrined in the Federal Law “On operational-investigative activities” The questions of performing operational-investigative activities and the restrictions on the constitutional rights of citizens, connected with them, are raised. Performing operational-investigative activities, requiring judicial authorization, is impossible without clear knowledge and understanding of not only the Federal Law “On operational-investigative activities” but also the decisions of both the Constitutional Court and the European Court of Human Rights. Understanding these documents makes it possible to competently and fully, in compliance with all the requirements of the law, draw up the necessary documents to obtain the permission of a court, competently and clearly determine which activity should be conducted in each case, taking into account the technical and other features of both the activity itself and the allocated funds. Purpose: to conduct a scientific study of operational-investigative activities of judicial authorization; to analyze the legislation governing the specifics of performing these activities, the powers of the subjects of operationalinvestigative activities when performing the considered activities. As the methods and methodology of conducting the work, formal-logical and dialectical methods, sociological, and historical methods were used. The scientific article is based on a sociological, theoretical, and historical method, on a set of techniques for understanding the legal status of an official, the theory of authorities, and a comparative analysis of legislative norms. The main methodological approach used in the scientific article is the theory of operational-investigative legislation, developed in the works of Russian lawyers. Main results: the study made it possible to identify the advantages and disadvantages of the regulatory framework governing the specifics of conducting operational-investigative activities requiring judicial authorization, as well as significant errors in law enforcement practice. Conclusions and substantiation of the novelty of the work: based on the analysis of the Federal Law “On operational-investigative activities”, insufficient legal elaboration of the legal regulation of operationalinvestigative activities of judicial authorization is substantiated. The ways of solving the existing problems are proposed, including by amending the current legislation on operational-investigative activities

Methodology for experimental study of wind turbines with vertical axis of rotation

The experimental methods for wind turbines performance investigation are divided into two major groups. The first group involves full scale wind turbines investigation at ambient field conditions. The second group involves laboratory investigation of scaled model wind turbines carried out in wind tunnel. A methodology for the laboratory investigation of a scaled model wind turbines with vertical axis of rotation - Darrieus, Savonius and hybrid configurations Darrieus-Savonius are presented in this study

Experimental testing of Rutland 503 wind turbine

Harnessing the wind energy potential for electricity generation is an environmentally friendly approach which is easily realizable in areas with the appropriate conditions. This paper presents the experimentally obtained results regarding the performance characteristics of Rutland 503 horizontal axis wind turbine