Bus diesel engine cooling system modelling, design and economic optimization

Engine cooling is one of main factors for a proper working engine. Specially rear engined buses, effect of ram air is very low. The aim of this thesis is to choose suitable radiator and intercooler with the engine dynamometer tests and mathematical model. As a result of this thesis, optimum radiator and intercooler will be designed with the component of the producer, so the dependence on manufacturers will disappear. Bus manufacturer can find alternative producers and reduce costs. In this context, 6 types of radiators, 7 types of intercooler and 3 types of fan were tested with 3 types of buses; front engined and radiator, mid engined and radiator, rear engined and radiator; in chasis dynamometer with climatic chamber tests, road tests and engine dynamometer tests. Also for 3 types of buses were modeled mathematically in MATLAB. As a result of thesis, results of road tests and climatic chamber tests overlap, systems with hydraulic fan provide better cooling performance then visco fan systems and heat capacity of the radiator and intercooler for the rear engined buses are nearly the half of the front engined bus. For same outer dimensioned radiators with optimum sizes of fin and tubes aluminium radiator has better cooling perofrmance than cupper radiator, intercooler dimensions can effect the radiator performance for 20%, engine dynamometer tests overlap with front engine buses but in rear engine buses tests does not suit, espacially in CAC line. Additionally fan position was investigated with CFD program Fluent and found that if more than ½ of the fan is out of louver fan performance decreases. At last mathematical model was investigated and found applicable.