944 resultados para Eletric car
Resumo:
In this study the cooling performance due to air flow and aerodynamics of the Formula Student open wheeled race car has been investigated and optimized with the help of CFD simulations and experimental validation. The race car in context previously suffered from overheating problems. Flow analysis was carried out based on the detailed race car 3D model (NITK Racing 2012 formula student race car). Wind tunnel experiments were carried out on the same. The results obtained from the computer simulations are compared with experimental results obtained from wind tunnel testing of the full car. Through this study it was possible to locate the problem areas and hence choose the best configuration for the cooling duct. The CFD analysis helped in calculating the mass flow rate, pressure and velocity distribution for different velocities of the car which is then used to determine the heat dissipated by the radiator. Area of flow separation could be visualized and made sure smooth airflow into the radiator core area. This significantly increased the cooling performance of the car with reduction in drag.
Resumo:
With the installation by the Pacific Electric Railway of a bus system in Pasadena to supplant most of its trolley lines, the problem of the comparison of the costs of the two systems naturally presented itself. The study here undertaken was originally started as just a comparison of the motor bus and Birney Safety Car, but as the work progressed it seemed advisable to include the trolley bus as well - a method of transportation that is comparatively new as far as development is concerned, but which seems to be finding increasing favor in the East.
Resumo:
We propose a system that can reliably track multiple cars in congested traffic environments. Our system's key basis is the implementation of a sequential Monte Carlo algorithm, which introduces robustness against problems arising due to the proximity between vehicles. By directly modelling occlusions and collisions between cars we obtain promising results on an urban traffic dataset. Extensions to this initial framework are also suggested. © 2010 IEEE.
Resumo:
论文分两部分:第一部分在参阅大量文献的基础上,对海洋声信道的特性及其对声遥控的影响做了分析和总结,并根据FSK调制信号的传播实验,对海洋声信道的一些特性进行了定性分析。第二部分详细地分析了CAR型声释放器的电路特性,并结合海洋声信道的特性及海上实验情况分析了CAR型声释放器的工作性能。
Resumo:
Introdução; Clima; Solos; Sistema de plantio; Propagação; Época de plantio; Variedades; Adubação; Cobertura morta; Tutoramento; Doenças; Pragas; Colheita.
Resumo:
Is it conceivable to contemplate a future without the car as the center of an urban transportation system? Can emerging economies grow without concomitant growth in car usage? San Pedro Sula, Honduras, is one city at a critical decision point about the future of transportation and mobility. Will it be a sustainable transport future that balances economic, environmental and social needs or will it be the traditional “predict and provide” approach that attempts to expand the capacity of the road system to meet future travel demand. This paper provides some background into the issue for this Central American city by describing the current urban transport system, current plans for improvement and outlines a process for defining a vision for a sustainable transport future in San Pedro Sula. The paper concludes with a challenge to all cities that currently have low automobile ownership rates to consider a sustainable transport system in order to “thrive” with transport choices for all residents rather than “choke” on congestion and the negative side effects thereof.
Resumo:
The problem to be examined here is the fluctuating pressure distribution along the open cavity of the sun-roof at the top of a car compartment due to gusts passing over the sun-roof. The aim of this test is to investigate the capability of a typical commercial CFD package, PHOENICS, in recognising pressure fluctuations occurring in an important automotive industrial problem. In particular to examine the accuracy of transporting pulsatory gusts traveling along the main flow through the use of finite volume methods with higher order schemes in the numercial solutins of the unsteady compressible Navier-Stokes equations. The Helmholtz equation is used to solve the sound distribution inside the car compartment, resulting from the externally induced fluctuations.
Resumo:
In this paper, the authors present a crashworthiness assessment and suggestions for modification of a conventionally designed rail vehicle with a driving cab (cab car). The analytical approach, based on numerical analysis, consisted of two stages. Firstly, the crashworthiness of the cab car was assessed by simulating a collision between the cab car and a rigid wall. Then, after analysing structural weaknesses, the design of the cab car was modified and simulated again in the same scenario. It was found that downward bending is an intrinsic weakness in conventional rail vehicles and that jackknifing is a main form of failures in conventional rail vehicle components. The cab car, as modified by the authors, overcomes the original weaknesses and shows the desired progressive collapse behaviour in simulation. The conclusions have general relevance for other studies but more importantly, point to the need for a rethink of some aspects of rail vehicle design.
Resumo:
Examines the Cambridge County Court ruling in Volkswagen Financial Services (UK) Ltd v Ramage on whether a clause in a car hire contract which allowed the finance company, upon repudiation of the contract after the hirer fell into arrears, to claim compensation equivalent to the lost future rental payments was unenforceable as a penalty clause, rather than being a reasonable pre-estimate of actual loss. Refers to case law including the Court of Appeal ruling in Anglo Auto Finance Co v James in considering the differing losses which would occur during the course of the hire term according to the natural depreciation of the value of the car. Notes the reasoning of the Court on: (1) contracts of hire compared with hire purchase agreements; (2) the comparative position of the parties and the freedom to contract elsewhere; and (3) the reasonable prediction of future losses.