Sharif Digital Repository

Today, the world energy crisis, the need to optimize its consumption and discussion to reduce fuel consumption has become a vital issue. The conventional vehicle air conditioning system due to compressor in refrigeration cycle, which has causes a severe loss in engine useful power, increasing fuel consumption, etc. Therefore, the main goal of this project is the feasibility of the vehicle cooler replacement with the vapor jet refrigeration cycle. In this cycle, the energy required for completing the refrigeration cycle is provided from the heat of the water inside the radiator that is possible with conventional refrigeration cycle. The first stage of this project includes design and... 

In this thesis a general model for simulation of solar cooler for domestic usage is developed. The model consists of 2 main parts: thermo-dynamical and economical calculations. The thermodynamic part consists of 4 sub models: a model for calculation of incoming solar radiation, cooling load demand calculation, the refrigeration cycle and the solar cycle with heat storage.As for hourly calculation of system performance part of the model produces the hourly received radiation data based on geographical position and orientation of the receiving surface. Base on results of the cooling load calculation for a 9 m2 studying room located in western part of Tehran, 1 TBR (3.516 kW) is chosen as... 

The aim of this investigation is the experimental study of nozzle exhaust jet flow effects on aerodynamic behavior of an air vehicle at transonic speeds. For this sake, a secondary jet injection is used by the ejector into test model. The ejector total pressure for jet injection varies between 0 (jet off) to 4 bar for simulating nozzle exhaust jet flow and supplying intake’s required mass flow rate. All tests were conducted at QRC Trisonic wind tunnel and at Mach number of 0.5 to 0.85 and angles of -4 to 6 deg. The aerodynamic force and pressure results were recorded in order to analyze the exhaust jet flow. This study revealed that the aerial vehicle drag becomes bigger than its free flight... 

This study aims to evaluate aerodynamic coefficients of an airplane with air breathing engine experimentally. In these experiments, an ejector is used to better simulate flying conditions and aerodynamic interferences generated in inlet and exhaust engine. Therefore, at first, an ejector was designed for simultaneous simulation of exit cold flow and inlet flow of engine. All tests were conducted at QRC Trisonic wind tunnel and at Mach number of 0.5 to 0.85, angles of -4 to 6 deg. and for various amounts of pressure ejector and control surfaces angles. Finally, for the Mach number of 0.5, effect of roughness on the aerodynamic coefficients was examined. The results showed that, drag... 

Nowadays, widespread needs for creating low pressure ambient in various industries make vacuum systems have different research and industrial applications. One of these applications is in cooling system of Rankine power cycle. In this case, the performance of the vacuum system has a direct and significant effect on the cooling performance of the condenser and consequently, power production of the steam turbine. Also, a considerable part of deration in thermal power plants industry is due to the thermal deration of the cooling systems. This is mostly because of malfunction of the condenser due to ambient temperature rise. Therefore, by providing suitable solutions to improve the efficiency... 

High-altitude simulation lab of chemical thrusters is one of the most important infrastructures for the development of space thrusters technology. In these laboratories, different sections are designed according to the requirements for simulation of the thrusters at specific pressure and temperature. The purpose of this research is to design a subset of the creation and preservation of vacuum for the purpose of ground testing of chemical thrusters. Vacuum preservation is more comprehensive than the vacuum creation and is usually the bottleneck of design, so the design of this subset is intended in the present study. To illustrate this, after introducing the basic concepts required, two... 

Today, global warming is one of the main concerns of human society. Many factors contribute to global warming and air pollution. Air pollution in the metropolis cities has influenced human life. Vehicles are considered as one of the major sources of air pollution. Vehicle air conditioners bring conform to passengers, but they increase fuel consumption. Increased fuel consumption results in the production of pollutants and air pollution. In this study, the ejector cooling system is proposed as a cooling system of a car air conditioning system, and its performance is studied. To this aim, first, an ejector cooling cycle equivalent to the compression cooling cycle is designed. The ejector is... 

Transportation is one of the essential parts of human life and at the same time one of the main sources of greenhouse gases emissions that are harmful to the environment. Therefore, the use of electric vehicles have become widespread in recent years due to limited capacity of natural resources and environmental issues. As a result, attention to climate control systems for electric vehicles and electric aircrafts is growing rapidly. According to multiple studies, the integrated air conditioning-heat pump system is a suitable option as the climate control system.In this research, an air conditioning-heat pump system has been proposed and studied, which works based on the vapor compression...