Sharif Digital Repository

Nowadays, computer simulations have an important role in the investigation of the thermal performance of the systems. In this thesis, a software program was developed for simulation of cooling system of an ER24PC Locomotive diesel engine. For this purpose, the C + + programming language is applied. One of the most important components in the cooling system is the radiator. In order to model the radiator, a relationship must be used to determine the heat transfer coefficient for coolant side and air side of the radiator. This relationship can be based on experimental, analytical, or numerical solutions. Offset strip fins are used in radiator of ER24PC locomotives. With application of... 

The Engine of a vehicle is an energy conversion system, where specific chemical energy is converted in to heat in a combustion chamber. In order to reduce thermal tension in the cylandr, part of heat is removed with the help of circulating water and it is dissipated in the radiator. As a result, part of input energy is wasted in to the atmosphere through cooling system in each cycle of engine. Heat recovery in the cooling system and preheating combustion air of fuel could enhance energy efficiency and it may contribute to fuel economy. Heat recovery may be realized with the help of heat pipes. Heat pipes may be utilized for heat recovery and preheating fuel or air whichare inlet to the... 

Heat pipe is a heat transfer device that may have a thermal conductance hundreds of times higher than that of copper. Currently, heat pipes have been used in numerous applications including satellite thermal management, energy systems for energy recovery and energy conversion, and electronics cooling, particularly in laptop and desktop computers. In this thesis, a new application of the heat pipe in an automotive engine is introduced. In this application, heat pipes are incorporated into the radiator of the automotive engine for more efficient heat transfer. In particular, the employment of the heat pipes would allow the gravity to be used as the driving force for the liquid... 

Optimization of heat transfer in vehicle's underhood which contains radiator, cylidir block, cylinder head and … with minimum pressure loss on engine is one of the most important problems of the car companies in all over the world.To design some cooling parts like simple radiators which doesn’t have a effective cooling effect, we can use equations.but for more complicated geometries which is morte efficient we have many complicated solutions.So in this condition computationl analysis and laboratories play an important role.in this condition we should consider that producing a sample and the process of verifying the result of test is too expensive.So recently the car companies prefare... 

Inhencemant of automobile radiator heat performance is the purpose of this study. Radiator fin shape, coolant fluid properties and influence of nanofluid studied in this research. Plain fin, louvered fin and vortex generator fin is choosen and design. With flow simulation influence of fin shape on heat performance is studied. After that, with considering radiator coolant fluid, the effect of antifreezing on fin heat transfer is evaluated. Then by addin nanoparticles to water and antifreezing solution, effect of nanofluid on heat transfer is evaluated. Results show that with increasing the air velocity for all geometries in the study , heat transfer and pressure drop is increased. But heat... 

Due to the development of heat pipes in different industries and special characteristics of heat pipes, in this study, it has been tried using computational fluid dynamics (CFD) method to simulate a heat pipe heat exchanger that can be a replacement for the normal radiator. The experimental model of this heat exchanger has been tested at past studies and the numerical simulation of the heat exchanger will analyze at present study. The use of heat pipe in the car radiator has many advantages such as reducing fluid pressure drop through the heat exchanger, high reliability due to the particular structure of the heat exchanger (individual performance of each heat pipe) and improving heat...