Current Issue : April - June Volume : 2016 Issue Number : 2 Articles : 6 Articles
This paper presents the first experimental and computational investigation into the aerodynamics of emergency response vehicles and focusses on reducing the additional drag that results from the customary practice of adding light-bars onto the vehicles� roofs. A series of wind tunnel experiments demonstrate the significant increase in drag that results from the light bars and show these can be minimized by reducing the flow separation caused by them. Simple potential improvements in the aerodynamic design of the light bars are investigated by combining Computational Fluid Dynamics (CFD) with Design of Experiments and meta modelling methods. An aerofoil-based roof design concept is shown to reduce the overall aerodynamic drag by up to 20% and an analysis of its effect on overall fuel consumption indicates that it offers a significant opportunity for improving the fuel economy and reducing emissions from emergency response vehicles. These benefits are now being realised by the UK�s ambulance services...
In this project it seeks to meet varying power and gas emission that occurs in a vehicle Chevrolet Corsa to reduce income of air into the intake manifold which also cause a change of pressure therein, and due to this pressure change, the voltage signal emitted by the MAP to the ECU will be affected. The experiment was carried out at different speeds regime as it tries to simulate the operation of an automobile to the topography of Ecuador, which is required to reach high engine rpm to overcome the pending there. While the experiment was carried during no real operating conditions, due that a car would never come to an obstruction of 75%, the data and analysis gives an idea of the seriousness of this is when there the obstruction in the air intake of the engine, and these are reflected directly in the engine performance....
The aim of this research is to compare which parameters may vary when braking on different Ministry of Transport (MOT) brake testers, such as roller bed brake tester and dynamometric platform. Different types of brake testers have been used and analyzed by the mechanical engineering staffs at the mechanical laboratory at the Miguel Hern�¡ndez University. It has been analyzed which parameters can vary the result of the brake test, and advances and disadvantages of each brake tester....
The growth in number and complexity of controlled electrical sub systems in the modern car has created a need for centralized information interchange point. The master controller provides this centralized unit. It interacts with all other networked control electronics to control the dynamic driving demands. In a hybrid vehicle, the master controller not only provides a communication interface, but also an efficient energy management, coordination and performance during the various vehicle-specific drive cycles. The control complexity at the master control unit is greater in the hybrid car because of the extra energy resources integrated into the vehicle. This work presents the design, implementation and testing of the Kiira EV SMACK vehicle master control unit. In the Kiira EV SMACK, the master controller oversees the human machine interfaces, low voltage electronics, the motor and generator controllers, battery management and thermal management systems. A model based design approach was followed to implement the controller logic for initiation of startup of the low level controllers and implementation of a power source switching strategy. The switching strategy is based on speed demands and available energy resources (battery state of charge and fuel capacity)....
As fuel temperature increases, both its viscosity and surface tension decrease, and this is helpful to improve fuel atomization\nand then better combustion and emission performances of engine. Based on the self-regulated temperature property\nof positive temperature coefficient material, this article used a positive temperature coefficient material as electric\nheating element to heat diesel fuel in fuel pipeline of diesel engine. A kind of BaTiO3-based positive temperature coefficient\nmaterial, with the Curie temperature of 230C and rated voltage of 24 V, was developed, and its micrograph and\nelement compositions were also analyzed. By the fuel pipeline wrapped in six positive temperature coefficient ceramics,\nits resistivityââ?¬â??temperature and heating characteristics were tested on a fuel pump bench. The experiments showed that\nin this installation, the surface temperature of six positive temperature coefficient ceramics rose to the equilibrium temperature\nonly for 100 s at rated voltage. In rated power supply for six positive temperature coefficient ceramics, the\ntemperature of injection fuel improved for 21Cââ?¬â??27C within 100 s, and then could keep constant. Using positive temperature\ncoefficient material to heat diesel in fuel pipeline of diesel engine, the injection mass per cycle had little change,\napproximately 0.3%/C. This study provides a beneficial reference for improving atomization of high-viscosity liquids by\nemploying positive temperature coefficient material without any control methods....
Advanced engines can achieve higher efficiencies and reduced emissions by operating in regimes with diluted fuel-air mixtures and higher compression ratios, but the range of stable engine operation is constrained by combustion initiation and flame propagation when dilution levels are high. An advanced ignition technology that reliably extends the operating range of internal combustion engines will aid practical implementation of nextgeneration high-efficiency engines. The microwave-assisted spark plug under development by Imagineering, Inc. of Japan has previously been shown to expand the stable operating range of gasoline-fueled engines through plasmaassisted combustion, but the factors limiting its operation were not well characterized. The present experimental study has two main goals: (1) to investigate the capability of the microwave-assisted spark plug towards expanding the stable operating range of wet-ethanol-fueled engines, and (2) to examine the factors affecting the extent to which microwaves enhance ignition processes. The stability range is investigated by examining the coefficient of variation of indicated mean effective pressure as a metric for instability, and indicated specific ethanol consumption as a metric for efficiency. Engine efficiency improved when the engine was run at slightly-lean air-fuel ratios, with the onset of instability eventually eliminating efficiency gains associated with lean-burn when mixtures become too dilute. Microwave-assisted ignition reduced dilution-triggered instability, improving efficiency compared to unstable spark-only operation at ultra-lean conditions. Microwave-assisted spark also promotes faster average early flame kernel development when un-enhanced flame kernel development is sufficiently slow. Correlations between microwave-assisted flame development enhancement and calculated in-cylinder parameters suggest a relation between enhancement and the amount of energy deposited into the flame kernel, but scatter prevented derivation of a unifying empirical correlation governing all tested cases....
Loading....