전체 글 썸네일형 리스트형 Spark and Ignition (2) Spark and Ignition (2) Imagine a electric wire with 220 Volt electricity flowing it. Now, assume you cut it some point of the wire and keep the gap around 1 mm, then of course the current stops to flow and connected electric devices stop working. The reason that the current stops is the electric resistance of air is much higher than those of copper wire. Then how can we overcome this resistance .. 더보기 Spark and Ignition (1) Spark and Ignition (1) Both of Diesel and Gasoline engine use a cylinder (more precisely, combustion chamber) to generate power to rotate crankshaft. Air and fuel mixture in the combustion chamber burns (or explodes) and the explosion pressure push down the piston connected to crankshaft. The diesel fuel has lower temperature point of ignition than gasoline around 250 deg C, and this temperature.. 더보기 Hazardous Emission of Vehicles Hazardous Emission of Vehicles It is true that vehicles bring us a lot of convenience, but in the other hand they also bring a lot of hazardous factors, such as traffic accident which can kill the users or the third parties, and emission gases from the vehicles. Emission gas has a wider meaning than the exhaust emission including every kind of gases emitted from a vehicle. These can be described.. 더보기 To Save Fuel To Save Fuel If we choose a vehicle, performance factors such as power, torque, maximum speed, etc are important factors to be considered for decision making, but maintenance and operation cost of the vehicle is also very important factor in view point of TCO (Total Cost of Ownership). For maintenance we need to consider consumables such as, engine oil, tire, air-cleaner filter, spark plug and s.. 더보기 Vehicle Performance (2) Vehicle Performance (2) Gradient Resistance This resistance force is originated from the gravity. If the road is up-hilled shape then we need stronger traction than plane road. If we can describe this resistance as an simple equation, it will be like below. G-Resistance » Weight x sine (Road Gradient) Rolling Resistance This resistance comes from the contacting surface between tire and road. Whe.. 더보기 Vehicle Performance (1) Vehicle Performance (1) When I was a very young boy, I liked to watch vehicles on the road, specific interest was given to the speed limit of the vehicle which was written on the right most side of the speedometer. The young boy thought that the number of the speedometer expressed the real maximum speed of the vehicle, which was not true (I have realized after joining a automotive manufacturing .. 더보기 Combustion (2)_Air and Fuel Combustion (2)_Air and Fuel (A/F Ratio) As written in part (1) of combustion, the composition of fuel is hydrocarbon (HC), but the chemical bonding of every kind of HC is different from each other. Depending on the type of bondage of HC, the type of combustion inside combustion chamber will also be decided. The picture below shows a couple of different kind of HC chemical structure. Paraffinic H.. 더보기 Combustion (1)_Heat Generation Combustion (1)_Heat Generation Just like human being the engine need to eat air and fuel to generate rotating power. In case of human being we call the power generation process as “digestion” but in the internal combustion engine case we have named it as “combustion”. Combustion is a kind of chemical reaction/ process which convert or change the structure of a certain material into other format .. 더보기 이전 1 2 3 4 5 다음
