Response of Starter Motor of an Engine Subjected to Random Vibrations

2014 ◽  
Vol 612 ◽  
pp. 9-16 ◽  
Author(s):  
Rameshwar Kendre ◽  
Satish Prabhune ◽  
Ratnakar Ghorpade
Keyword(s):  
Mechanical Energy ◽  
Electrical Energy ◽  
Random Excitation ◽  
Spectral Density Function ◽  
Motor Vehicles ◽  
Random Vibrations ◽  
Element Analysis ◽  
Starter Motor ◽  
Power Spectral ◽  
Continuous Progress

The automobile sector requires continuous progress in development of ‘Starter Motor’ by innovative approaches although significant progresses are made in the past. Development of Starter Motor has made it possible to start the engine by electrical means instead of doing it manually. The outstanding features of this motor are they can produce the maximum starting torque to crank the engine. In this case, we use electrical energy and convert it to mechanical energy in order to start the engine in motor vehicles. As the starter motor is mounted near the engine; vibrational disturbances produced due to either uneven road conditions or engine vibrations or both hampering the performance of starter motor which may result in breaking of component of motors. Vehicle will experience vibrations whose values are un-predictable at certain point of time causing random excitation and random vibrations. Aim of paper is to perform analytical formulation for Power Spectral Density function of Starter Motor by treating it as a cantilever beam and to find its response to random vibrations by using Finite Element Analysis (FEA).

scholarly journals The Use Of Microturbines as an Energy Converter For Motor Transport

2019 ◽  
Vol 8 (10) ◽  
pp. 2700-2703
Keyword(s):  
Fuel Consumption ◽  
High Speed ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Motor Vehicles ◽  
Turbine Engine ◽  
Range Extender ◽  
Traction Motors

At this stage of the development of vehicles with a combined power plant, one of the areas of development is the study of the introduction of a low-power gas turbine engine, the so-called microturbine, as a converter of thermal energy into mechanical. This solution has numerous positive aspects related to its fuel consumption, small dimensions, high efficiency, as well as a number of performance indicators. In this case, the vehicle is also equipped with a high-speed generator with the goal of converting the mechanical energy of the microturbine into electrical energy. This ensures the microturbine operation in a given range on the characteristic of optimal fuel consumption. The article contains an analysis of the use of microturbine generators in vehicles; some constructive solutions are considered as well. An overview of vehicles with microturbine generators and their comparison with traditional internal combustion engines is given. The movement of the vehicle is carried out by one or several traction motors. More than ten developments of motor vehicles using the microturbine as an additional source of energy for vehicles with traction electric drive are already known in the world, including MiTRE (Microturbine Range Extender). Among such vehicles, one can name the Trolza "Ecobus" buses, Delta Hypercar supercar, Isuzu NPR trucks, Mack Truck, Kenworth.

Performance of a Bi-Stable Resonator With Random Input Vibrations

2016 ◽  
Author(s):  
Wei Yang ◽  
Shahrzad Towfighian
Keyword(s):  
Energy Harvesting ◽  
Frequency Spectrum ◽  
Mechanical Energy ◽  
Low Frequency ◽  
Random Excitation ◽  
Random Input ◽  
Vibration Energy Harvesting ◽  
Remote Sensors ◽  
Power Spectral ◽  
Linear Resonance

By converting ambient mechanical energy to electricity, vibration energy harvesting, enable powering of low-power remote sensors. However, realistic ambient vibrations are random and spread over a wide frequency spectrum, which means linear resonators fail to perform effectively because of their narrow frequency bandwidth. Hence, there is a need for thorough investigation of performance of nonlinear resonators with Gaussian random vibration. This article presents a simulation study on the use of magnets to improve a nonlinear oscillator for energy harvesting from broadband low frequency random excitation. The resonator response to Gaussian distribution random input is investigated using root mean square value and power spectral density of voltage. The obtained results show that in a broadband low frequency spectrum the nonlinear system performs better than linear resonance. The optimal performance is found when the distance between two magnets is near the mono-stable to bi-stable transition regime.

Random Excitation of a Car Component from the Road

2013 ◽  
Vol 430 ◽  
pp. 184-190
Author(s):  
Curtean Razvan ◽  
Iulian Lupea
Keyword(s):  
Finite Element ◽  
Coming Out ◽  
Transfer Functions ◽  
Random Excitation ◽  
Vehicle Speed ◽  
Random Vibrations ◽  
Element Analysis ◽  
Component Structure ◽  
The Road ◽  
Car Component

In the present paper aspects regarding the analytical modeling, the simulation and the experiments related to random vibrations, with applications to automotive industry, are discussed. Simplified car dynamical models based on lumped masses, springs and dampers being exposed to random vibrations, are considered. The power spectral density is used to define the excitation produced by the unevenness of the road surface which are correlated to the vehicle speed. Two different approaches are observed in parallel. The analytical one is using the dynamical model of the car, the random excitation estimation, the transfer functions from the excitation sources to the target, and the response at the comfort points or the points of interest. The associated numerical calculations are performed with Matlab. For the second approach the finite element models of the car simplified structure are created and the simulations are performed. Statistical tools are used to describe the excitation sources and the response. Good correlation of the results for the two approached is observed. In the sequel a real car component made of plastic is considered. The estimation of the component structure stress with probability of 1σ, 2σ and 3σ, are coming out from the simulation of the part subjected to random vibrations by using finite element analysis. Frequency response functions (FRF) are experimentally measured in the laboratory by placing the plastic component on a shaker. The measured FRFs and the results are compared to the ones resulted from the simulation, observing a good correlation. The output of the random vibration analysis can be used to estimate the fatigue of the component.

Reduction of structural vibrations with the piezoelectric stacks ring

2020 ◽  
Vol 64 (1-4) ◽  
pp. 729-736
Author(s):  
Jincheng He ◽  
Xing Tan ◽  
Wang Tao ◽  
Xinhai Wu ◽  
Huan He ◽  
...  
Keyword(s):  
Vibration Control ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Structural Vibrations ◽  
Rotor Systems ◽  
Fea Model ◽  
Piezoelectric Stacks ◽  
Shunt Damping ◽  
Reduction Effect ◽  
Euler Bernoulli Beam

It is known that piezoelectric material shunted with external circuits can convert mechanical energy to electrical energy, which is so called piezoelectric shunt damping technology. In this paper, a piezoelectric stacks ring (PSR) is designed for vibration control of beams and rotor systems. A relative simple electromechanical model of an Euler Bernoulli beam supported by two piezoelectric stacks shunted with resonant RL circuits is established. The equation of motion of such simplified system has been derived using Hamilton’s principle. A more realistic FEA model is developed. The numerical analysis is carried out using COMSOL® and the simulation results show a significant reduction of vibration amplitude at the specific natural frequencies. Using finite element method, the influence of circuit parameters on lateral vibration control is discussed. A preliminary experiment of a prototype PSR verifies the PSR’s vibration reduction effect.

Experimental Observation of Fractal-Regular Surfaces and a Transformation Scheme for Extracting Fractal Parameters

2005 ◽  
Author(s):  
Shao Wang ◽  
Wai Kin Chan
Keyword(s):  
Silicon Wafer ◽  
Roughness Parameter ◽  
Hard Disk ◽  
Spectral Density Function ◽  
Power Spectral ◽  
Fractal Parameters ◽  
Asperity Contacts ◽  
Fractal Roughness ◽  
Magnetic Hard Disk ◽  
Wafer Surfaces

To account for the effects of asperity contacts at various length scales, it is appropriate to characterize an engineering surface as a fractal-regular surface. In spite of significant theoretical advancement, there is a desperate need for experimental verification of the theory of fractal-regular surfaces and a consistent scheme of obtaining the fractal parameters. In the present study, the existence of a fractal region and a regular-shape region in the power spectral density function for fractal-regular surfaces was confirmed experimentally, for the first time, with data obtained from magnetic hard disk and silicon wafer surfaces. A novel scheme involving a variable transformation was developed to extract fractal parameters. This scheme was validated by accurate recovery of fractal parameters from simulated surfaces. The fractal dimension, the fractal roughness parameter and the fractal domain length were found for magnetic hard disk and silicon wafer surfaces.

scholarly journals Empirical Analysis of High Voltage Battery Pack Cells for Electric Racing Vehicles

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1556
Author(s):  
Khaled Sehil ◽  
Basem Alamri ◽  
Mohammed Alqarni ◽  
Abdulhafid Sallama ◽  
Mohamed Darwish
Keyword(s):  
Electrical Energy ◽  
Comparative Investigation ◽  
Motor Vehicles ◽  
Race Car ◽  
Battery Packs ◽  
High Voltage Battery ◽  
Li Ion ◽  
Rapid Deployment ◽  
Conclusion Section ◽  
Battery Cells

This paper examines the specifications of lithium battery cells, which are considered one of the most vital sources for electrical energy storage units. The specifications have been covered to associate battery performance with its usage for electrically powered motor vehicles. With the motivation of rapid deployment of electric vehicles (EVs) around the world, the key contribution of this study is to provide a comparative investigation of well-known commercially available Li-ion battery cells used as a pack for electric race car. Five lithium cells from different manufacturers were analyzed for start voltage, end voltage, current, and the use of active cooling under different test conditions. Thermal imaging was used to provide more comprehensive analysis of tested battery packs. The outcomes of this experimental investigation are described in the sections below in the order in which the analyses were conducted. The key findings of this study are presented in the conclusion section.

Numerical Prediction of Noise Radiated From a Panel Subjected to Boundary Layer Excitation

1999 ◽  
Author(s):  
Michael Allen ◽  
Nickolas Vlahopoulos
Keyword(s):  
Boundary Layer ◽  
Finite Element ◽  
Boundary Element ◽  
Transfer Functions ◽  
Element Model ◽  
Acoustic Response ◽  
Spectral Densities ◽  
Wind Noise ◽  
Element Analysis ◽  
Power Spectral

Abstract In this paper an algorithm is developed for combining finite element analysis and boundary element techniques in order to compute the noise radiated from a panel subjected to boundary layer excitation. The excitation is presented in terms of the auto and cross power spectral densities of the fluctuating wall pressure. The structural finite element model for the panel is divided into a number of sub-panels. A uniform fluctuating pressure is applied as excitation on each sub-panel separately. The corresponding vibration is computed, and is utilized as excitation for an acoustic boundary element analysis. The acoustic response is computed at any data recovery point of interest. The relationships between the acoustic response and the pressure excitation applied at each particular sub-panel constitute a set of transfer functions. They are combined with the spectral densities of the excitation for computing the noise generated from the vibration of the panel subjected to the boundary layer excitation. The development presented in this paper has the potential of computing wind noise in automotive applications, or boundary layer noise in aircraft applications.

scholarly journals Feasibility study of power generation using a turbine mounted in aircraft wing

2018 ◽  
Vol 7 (2-1) ◽  
pp. 433
Author(s):  
K. Sri Vamsi Krishna ◽  
Shiva Prasad ◽  
R. Sabari Vihar ◽  
K. Babitha ◽  
K Veeranjaneyulu ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Power Systems ◽  
Free Stream ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Aircraft Wing ◽  
Aerodynamic Efficiency ◽  
Turbulent Reynolds Number ◽  
Main Motive ◽  
Emergency Power

The main objective of this study is to increase the aerodynamic efficiency of turbine mounted novel wing. The main motive behind this work is to reduce the drag by attaining the positive velocity gradient and generate power by converting the stagnation pressure which also acts as emergency power source. By using the energy source of free stream air, Mechanical energy is converted into electrical energy. The obtained power is presented in terms of voltage generated at various angles of attack with different Reynolds number. Experimental analysis is carried out for NACA4415 airfoil at various angles with respect to free stream ranging from 0deg to 30deg from laminar to turbulent Reynolds number. The results were obtained using the research tunnel at IARE aerodynamic facility center. The aerodynamic advantage of this design in terms of voltage is 9.5 V at 35m/s which can be utilized for the aircraft on board power systems.

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