Search results for "Automotive engineering"
showing 10 items of 483 documents
Analysis and optimization against buckling of beams interacting with elastic foundation
2017
We consider an infinite continuous elastic beam that interacts with linearly elastic foundation and is under compression. The problem of the beam buckling is formulated and analyzed. Then the optimization of beam against buckling is investigated. As a design variable (control function) we take the parameters of cross-section distribution of the beam from the set of periodic functions and transform the original problem of optimization of infinite beam to the corresponding problem defined at the finite interval. All investigations are on the whole founded on the analytical variational approaches and the optimal solutions are studied as a function of problems parameters. peerReviewed
Vibrations of a continuous web on elastic supports
2017
We consider an infinite, homogenous linearly elastic beam resting on a system of linearly elastic supports, as an idealized model for a paper web in the middle of a cylinder-based dryer section. We obtain closed-form analytical expressions for the eigenfrequencies and the eigenmodes. The frequencies increase as the support rigidity is increased. Each frequency is bounded from above by the solution with absolutely rigid supports, and from below by the solution in the limit of vanishing support rigidity. Thus in a real system, the natural frequencies will be lower than predicted by commonly used models with rigid supports. peerReviewed
The use of results of spectral analysis of synchronous generator output voltage for technical diagnostics.
2006
The method of technical diagnostics of ship diesel engine-generator installations is offered. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. On these parameters it is possible to judge quality of course of working processes in diesel engine cylinder, its technical condition. This method is applicable to piston compressor installations with the electric drive.
Equivalent circuit analysis of solid-rotor induction machines with reference to turbocharger accelerator applications
2006
Theoretical, numerical and experimental studies are described that have been carried out to develop a solid-rotor induction machine design for a particularly demanding application as an accelerator drive for a diesel engine turbocharger. In this application the turbo-motor will be required to operate at speeds of up to 130 000 rpm and in temperatures that can exceed 200°C. The results show that the equivalent circuit gives predictions that are of sufficient precision for design purposes and provides a useful design tool. It is shown that the use of a solid rotor affects the value of the stator leakage reactance and influences the motor performance through this effect as well as by presentin…
Optimising the efficiency of olive harvesting considering operator safety
2019
Mechanical-assisted harvesting of olives, which is carried out using hand-held harvesting units that detach the drupes through vibration supplied by electric motor or combustion engines, is a widespread method used in southern Italy. Such machines are able to harvest more than 80% of the overall quantity of olives available per tree in 5–10 min, but their performance is influenced by several factors related to the mechanical characteristics of the device and to the features of the trees. Here the problem of optimising harvesting efficiency whilst minimising the health risks to the operators is investigated, with the aim of demonstrating that it is possible to determine an optimum harvesting…
Comparison between 3-ph and 6-ph PMSM drives for the electric propulsion of unmanned aerial vehicles
2021
The full electric aircraft concept requires accurate design and suitable choice and integration of all the used components. Obviously, the electric propulsion drive is one of the most important on-board equipment. Both power converters and electric motors must have low weight, suitable overload capacity and high reliability. In this paper, two possible solutions of electric propulsion motor for unmanned aerial vehicle are investigated. Sizes, weight and some features of a three-phase PMSM motor are compared to those of a six-phase motor obtained by an appropriate rewinding of the armature, with fixed stator and rotor magnetic circuits. The losses obtained from the numerical analyzes are com…
Energy management strategy to reduce pollutant emissions during the catalyst light-off of parallel hybrid vehicles
2020
Abstract The transportation sector is a major contributor to both air pollution and greenhouse gas emissions. Hybrid electric vehicles can reduce fuel consumption and CO2 emissions by optimizing the energy management of the powertrain. The purpose of this study is to examine the trade-off between regulated pollutant emissions and hybrid powertrain efficiency. The thermal dynamics of the three-way catalyst are taken into account in order to optimize the light-off. Experimental campaigns are conducted on a spark-ignition engine to introduce simplified models for emissions, exhaust gas temperature, catalyst heat transfers and efficiency. These models are used to determine the optimal distribut…
Industry 4.0: Advanced digital solutions implemented on a close power loop test bench
2021
Abstract The paradigm of Industry 4.0 allows to increase the efficiency and effectiveness of the production. Companies that will implement advanced solutions in production systems will increase their level of competitiveness and will be able reach high market shares. The present paper is focused on the development of advanced digital solutions to be implemented on a close power loop test bench designed to test high power transmissions for naval unit. In particular, the test configuration consists of a back-to-back connection between two identical mechanical reducers. Since the efficiency of these systems are very high, it is not necessary to use large electric motors, thus managing to conta…
A Two-Stage Fault Detection and Classification Scheme for Electrical Pitch Drives in Offshore Wind Farms Using Support Vector Machine
2019
Pitch systems are one of the components with the most frequent failure in wind turbines. This paper presents a two-stage fault detection and classification scheme for electric motor drives in wind turbine pitch systems. The presented approach is suitable for application in offshore wind farms with electric pitch systems driven by induction motors as well as permanent magnet synchronous motors. The adopted strategy utilizes three-phase motor current sensing at the pitch drives for fault detection and only when a fault condition is detected at this stage, features extracted from the current signals are transmitted to a support vector machine classifier located centrally to the wind farm. The …
Sustainable Energy Supply in Vietnam
2020
The steep growth of electricity demand in Vietnam (11% per year on average since 2006) calls for a deep rethinking of the Vietnamese electrical power system. Its topological structure indeed may not be well suited for a deep penetration of renewable energy sources and a predictable increase of reactive industrial loads. The Vietnamese power system is described and a few analytical methods are considered for its study both in steady state and in dynamic conditions in different scenarios. The power system simulation software Neplan is used for the implementation of the system’s model and the performing of the dynamic analysis.