Sharif Digital Repository

Tehran, with approximately 750 km2 of land area, a population of more than 8 million people with about 4 million active on-road vehicles, is dealing with serious air pollution problems. To model the environmental phenomenon precisely, this study aims to develop on-road air pollutant emission factor matrices based on existing traffic in Tehran routes and to run air quality modelling within Tehran geographic boundaries. We developed emission factor matrices using SMOKES-MOVES emission modeling system. To do so, we calculated on-road emission factors from actual traffic-related data and run MOVES emission model. And use use them for different pollutants considered in air quality models. Then,... 

In this thesis the hourly concentration of different gaseous air pollutants in Tehran is modeled using Land Use Regression (LUR) and Artificial Neural Network, separately. Both models are provided with the same set of input data; the first step is to find these data. Since traffic affects air pollution, information about traffic conditions is one of the main inputs in air pollution modeling. Therefore, to obtain traffic information, in this thesis, first a novel method is developed to extract and analyze Google Maps traffic data. In this method, image processing is used along with the Geographic Information System (GIS) to count the number of pixels of different traffic colors for each road... 

Aerodynamic shape optimization has been always of great importance in aerospace design. Recent advancements in computational algorithms and hardware, has made it feasible to have advanced optimization as a standard part of desing procedure. Here we have promoted aerodynamic optimization of air propeller.
Propeller optimization process requires a propeller performance analysis program and an efficient optimization algorithm. A vortex lattice model is used for the propeller performance analysis and a computer program is developed based on it. Experiment and litritures are used for validation of VLM code. In order to optimize the propeller peformance, propeller efficiency is applied as cost... 

In present study, two bioreactors for biological and chemical removal of nitrogen oxides are modeled. Nitrogen oxides are of the most important pollutants in flue gas stream. These components are hazardous materials and could lead to acid rain, ground-level ozone, smog and the depletion of ozone layer. There are several methods for removing these pollutants which are categorized to two main groups: non-biological and biological methods. Biological removal has the advantage of removing the pollutants by an acceptable efficiency. In present study, two packed-bed bioreactors are modeled by the means of considering two kinds of biological removal mechanism in defined operating conditions. The... 

In this paper evaluate the short-term effects of air pollution on the mortality rate caused by cardiovascular problems, respiratory problems, digestive problems and tumors and cancers. This is done by using daily mortality data of Tehran, Tabriz, Mashad, Shiraz, Ahwaz and Isfahan during the years 1390 to 1394, we also use daily measurements of pollutant levels including Carbon-monooxcide, Sulfure-dioxide, Oxides of Nitrogen, Ozone and Particulate matters in the same period. The effects are estimad by looking at the relation of daily mortality in each city along with its pollution level. By controling for the weather conditions and city and month fixed effects, we find significant positive... 

MILD combustion can be a promising technology to prevent global warming. In this study, for the first time, the numerical simulation of MILD spray combustion of kerosene fuel with preheated and diluted air has been conducted in the faculty's SMSTR test stand. The modeling framework is based on the Reynolds averaged Navier-Stokes turbulence approach and the standard k–ε model, the DPM discrete phase model, and the EDC combustion model, using the skeletal chemical mechanism of Jet A POSF10325 kerosene with the air and droplet being tracked in Lagrangian coordinates. The simulation is done in a steady state and by an axisymmetric method, and the effects of inlet oxygen concentration, inlet air... 

All over the world availability of electrical power is an important matter. Electrical power is a basic requirement in each country so with increasing the demand, supply system should be adjusted.Compressed Air Energy System (CAES) stores the excessive produced energy as compressed air and will inject it to gas turbine to produce energy in peak load hours.This project aim is modeling and analyzing of CAES considering reliability. In this project some of failure mechanisms have been identified and modeled and then the performance effect on system failure have been surveyed. This project innovation is incorporating operational models with reliability to determine the best performance for... 

Concentrations of air pollutants emitted by motor vehicles in traffic tunnels, due to low access of tunnels to Open space increases rapidly. Increasing the tunnel pollutant concentration, decreases tunnel air quality level which is very dangerous for human health. Thus study of traffic tunnel air pollution concentration and dispersion is important for offering control strategies in these spaces. This investigation has been tried to study vehicular pollutants emission and dispersion inside traffic tunnel by data collection that involves traffic, meteorology and air pollutants characteristics in a urban tunnel. So data collection was carried out in the Resalat tunnel located in urban... 

Nowadays, energy has become a vital issue. Earth to Air Heat Exchanger (EAHE) is a technique that promotes energy saving. EAHE is a non-conventional technique that utilizes the thermal potential of the geothermal energy for space cooling/heating. In the agricultural sector, using the grounds energy for air conditioning of greenhouses can be highly effective. In this study, a transient implicit computational fluid dynamics model is developed to simulate the thermal performance of EAHEs. The developed model is validated against available experimental studies in the literature. Good agreement between simulated results and experimental data is obtained. In the following, the heat exchanger is... 

Iran's experience shows that either single or combined power generation cycles, face heavy summer performance deficiencies. The most limitation of power generation in steam cycles is due to their poor condenser performance.The less condenser performance, the more turbine back pressure, and the more turbine back pressure, the less cycle power generation. The main objective of the present study is to reduce steam turbine back pressure in the combined cycle of an organic Rankine-vapor compression refrigeration by installing heat pipes in suitable locations inside the Air cooled condense (ACC). In order to do so, a commercial numerical simulation solver (FLUENT) is used to find the most suitable... 

Environmental regulations with respect to the marine diesel emissions have become stricter during recent years, thereby imposing traffic limitations on Iranian ships preventing them to enter emission control areas. Nitrogen oxides (NOx), as one of most important air pollutants, have adverse impacts on public health and ecosystem, so as the ships are the primary source of NOx internationally, the after-treatment system finds more urge to be developed. In this study, a NOx reduction system using non-thermal plasma technology is studied in order to determine its application and efficiency for NOx removal from the exhaust gas of Iranian marine diesel engines. Meanwhile, important factors were... 

City of Karaj with 2 million population used to enjoy very clean and accommodating air and environment . This congenial condition was due to agricultural and gardening activities of the local population . This way of life has undergone a profound change due to a change in the economic activities of the local population from farming and agriculture to industrial activities . And this has brought particulate matter wich has been exacerbated in the recent years . With the additional onslaught of the dust storms coming from the neighboring countries due to drying up of rivers and lagoons .The main object of this work was to obtain the spectrum of the PM and the additional component of PM that... 

Air pollution modeling is a powerful and low-cost tool for taking appropriate strategies to control air pollution. In this research, the effects of vegetation on air pollutant dispersion were studied using computational fluid dynamics models. At the beginning, aerodynamics and thermal effects of vegetation on reactive pollutant dispersion including NO, NO2 and O3 under photochemistry cycle were investigated in two different geometries. In the first geometry, tree planting in an urban environment involving several canyons was simulated. Results show that tree planting causes flow reversal, temperature decrease, and concentration field change. Concentration change of each pollutant not only... 

Air pollution is known as one of the most important problems of large cities. The main reason for such air pollution is the increase in using private vehicles. There are some solutions for controlling and reducing air pollution. One efficient way to achieve this goal is by imposing taxes on aspects of private vehicles. The purpose of this study is to investigate the effect of taxes on different aspects of private cars to reduce city air pollution, by (1) promoting users to purchase smaller and higher vehicle technology including electric cars, and drive less, and (2) forcing local car manufacturing companies by market demand mechanism to improve technology in their products. This study is a... 

This study aimed to estimate and simulate the phenomenon of buzz in a supersonic air intake and examine the effects of turbulence models on the accuracy and quality of modeling this phenomenon was divided into two parts. In the first part, turbulence models and characteristics of each of them in modeling supersonic flow was studied as well as available researches were investigated to achieve appropriate numerical method for numerical analysis of intakes using turbulence models. In the second part, one axial symmetry intake of the compound density type was taken which designed for Mach number of 2.0 in order to achieve accurate numerical methods and validate it to model intakes flow. With ... 

Particulate matter is an important source of air pollution. Particulate matters have an Undesirable effect on the environment, economic, and the health of Tehran Citizens. Annually, more than 8 thousands of tons of mineral dust from Internal and external resources deposit in Tehran city. In this project, the increase in the level of PM10 concentration during June, 12th to 14th, 2015 have been considered. The intrusion and dispersion of mineral dust during June, 11th to 15h, 2015 have been simulated with the HYSPLIT Model. Also, the Trajectory of particle end in Tehran during the mentioned days simulated and plotted with the HYSPLIT. The results show that more than 85% of PM10 reported by Air... 

Today global network of transportation is mainstream for economic growth and business development, growth in population made a need in optimization of using routes in global air transportation network, research shows cooperating with Airline Alliances is beneficial and gives much more freedom to their members in schedule planning and pricing as well as common interest in market share in international market. Joining an alliance affects decision making process of airline (e.g. fleet design, scheduling, route planning and crew assignment) in competitive market. Difficulty and complexity of evaluation in cooperative decision making that needs research to develop a model to evaluate decision... 

Industrialization has brought about air pollution which is one of the most important factors threatening human health. The most efficient method to improve air quality include preventing the emission of pollutants by making laws and regulations. In order to set appropriate regulations, there needs to be a correct understanding of the problem. The purpose of this research is to identify such factors and create a correct understnding of the problem in Iran by constructing a Model of Iranian air qulity. The model used in this research, CMAQ is one of the most comprehensive and state of the art models in transport of pollutnts and chemical reactions in the atmosphere. The inputs into CMAQ... 

Inappropriate performance of the air-cooled condensers in the process industry will make the flow out of the air cooler not fully condensate and its pressure is greater than the design value. This will lead to product loss and safety issues. In this study, factors affecting the performance of air cooler and various solutions to solve these problems have been identified. As a case study, the first distillation tower of the Ali Siana Petrochemical Complex, which disrupts its function in some months of the year, has been investigated. Aspen Hysys process simulation software simulates the naphtha splitter unit and the Aspen Exchangers Design & Rating software simulates the air cooled condesor...