Sharif Digital Repository

Noise emission from vehicles in urban transportation has become of interest for researchers in addition to the engine exhaust gas emissions due to its significant effect on public health. In this work, an optimal energy management strategy is proposed for a hybrid electric vehicle (HEV) by taking the effect of engine noise into account. The engine noise is calculated based on a pressure-based combustion noise model at different operating points of a 1.5 L gasoline engine. The optimal operating points of the engine are defined using the calculated engine noise from in-cylinder pressure data and experimental data of brake specific fuel consumption (FC). A modification on the electric assist... 

Hybrid electric vehicles (HEVs) have been developed as a promising way to decrease the fuel consumption and emissions of conventional vehicles. Although the noise emission of HEVs is generally lower than that of conventional vehicles, it is still an issue, especially in urban transportation. In this paper, a power management strategy is developed to minimize the annoying noise of the engine for an HEV. This is a modified version of the strategy that was originally established based on the speed ratio of continuously variable transmission (CVT) as the control parameter (CVT-based strategy). The engine combustion noise is assessed using the experimental data of the in-cylinder pressure. Also,... 

Flow around a 2D circular cylinder with attached swinging thin splitter plates is numerically investigated. The ratio of the plates’ length to the cylinder diameter is 1 ([Formula presented]=1) where L is the Plates’ length and D is the cylinder diameter. The plates are attached at ±55 degrees (trigonometric angle) downstream and are forced to oscillate at different ratios of the natural vortex shedding frequencies with magnitudes of FR=0.75,1,1.25,1.5 and 2. The oscillation amplitude “α” as the other main variable ranges from 10 to 18 degrees. Two-dimensional simulations are carried out at the Reynolds number 100, and then extended to higher Reynolds number of 200. The results show that in... 

Certain stratified charge divided chamber engines have a very small pre-chamber, equipped with a spark plug and a main chamber connected to the pre-chamber through nozzles, A theoretical model is presented in this research to predict ignition delay and initiation of combustion in the pre-chamber. It considers flame progress in the pre-chamber up to the point where the flame penetrates the main chamber through the connecting nozzles. Step by step calculations then continue in the main chamber and the mass fraction burned and the energy release rate are calculated. The process continues to the point where all the fuel is burned. At each step, due to a one degree rotation of the crank shaft,...