Sharif Digital Repository

The present research aims at designing a hybrid powertrain for the urban utility vehicles whose internal combustion engines consume more fuel due to idling during most of the time of their mission in the cities. This design has considered development of a hybrid powertrain with the least changes in the vehicle together with a simultaneous lower cost. At first some experiments were conducted to examine the feasibility of using the hybrid powertrain for the urban utility vehicles. One of the results of this test was the speed of these vehicles in different times of working and we can achieved a standard drive cycle though separate methods by analyzing this result. The drive cycle is one of the... 

Energy management strategies (EMSs) play a crucial role in enhancing the performance of electric vehicles (EVs). This Ph.D. thesis focuses on developing an intelligent EMS (IESM) aimed at mitigating battery degradation by optimally splitting the load current within a hybrid energy storage system (HESS) that integrates batteries and supercapacitors (SCs) in a connected EV. The battery and SC packs are arranged in a semi-active topology utilizing a bi-directional DC-DC converter, which regulates the SC current through a model predictive control (MPC) supervisory controller. Initially, a straightforward approach is proposed for the real-time modeling of EV, including their primary electrical... 

In this thesis, combustion of liquid fuel spray under the condition of hot and diluted oxidizer, has been investigated. To this end, a novel type laboratory-scale test rig was designed to study the physics governing the MILD-Spray combustion conditions with an applied approach. The underlined test rig eliminates the operational problems of its predecessor test stands and is used for a heavier fuel with much more complex chemical composition (kerosene). The test section is axially symmetrical, in which the fuel is injected by a pressure-swirl atomizer in the direction of hot and diluted co-flowing air. With the use of the aforesaid test rig, the effect of variables such as oxygen... 

Monitoring driving behaviors of drivers, would avoid their dangerous behaviors and remarkably raise the safety. Nowadays real-time supervision is considered as one of the modern methods of controlling driving behaviors. Previously, due to expensive costs of required equipments and other restrictions, this kind of supervision hasn't been considered fairly. Nowadays increasing usage of smart phones, which contain multiple sensors, enables this type of supervision with lower costs. In the present study we would present some models, to assess the driving behavior via smart phone sensors such as accelerometer, gyroscope and rotation vector  

In practice, structures made of concrete are full of cracks. The strength of concrete is mainly determined by the tensile strength, which is about 10% of the compressive strength. As long as cracking in concrete is unavoidable, we have to try to minimize their detrimental effects. This objective can be achieved by resisting (or limiting) propagation of existing cracks. Because of this, reinforcement (mostly steel) is used to increase the carrying capacity of the material and to control the development of cracks. Concrete structures that fail, already shows a large number of large and small cracks before their maximum carrying capacity is reached. The failure of concrete can be characterized... 

The purpose of this research is to monitor the health of structures using the updated finite element model, in which digital images are used to optimize the numerical model. Structural Health Monitoring (SHM) is always an important and significant issue that has attracted the attention of many researchers in recent years. In general, some researches have been conducted in this field using physical sensors that provide discrete data to the system for analysis. Using cameras to monitor the structure makes it possible to extract continuous and integrated data from the structure using digital images, which is a significant advantage compared to physical sensors.In this research, a steel... 

Conformal Field Theory provides an efficient method for studying physical problems in critical point. Correlation length becomes converge in this point. It can also be clarified that some curves are observed in geometrical phase transition which are conformal invariant and they can be studied using SLE(k). The first mathematical generalization of SLE(k) while keeping the self-similarity property, leads to SLE(k,p). Conformal field theory and SLE are interrelated and their parameters are interpretable for each other. One usually studies the problem in the upper-half plane. Here we consider the problem using a map like (w=L/π Ln z) between the upper-half plane and a special region (e.g. a...