Simulation Research On Interior Single-Phase Flow Field Of Ethanol Gasoline Vehicle Exhaust Pipe

In recent years, the promotion usage of ethanol gasoline in China has made good progress, which not only eases the oil crisis, but also improves the situation of vehicle exhaust emissions effectively. However, the ethanol gasoline has brought some new problems at the same time. In these northern cold regions of our country in winter, due to the hydrophilic properties of ethanol gasoline and the poor combustion conditions caused by the low temperature environment, the water content of vehicle exhaust emission gets an obvious increase compared to the past. The water will accumulate continuously in the exhaust pipe while the vehicles are running with the fuel consumption. And the water falls on the street through the tail pipe ultimately. These water drops meet the low temperature and then freeze up, forming a layer of ice covering the road, which has made a serious effect on the traffic conditions. In order to settle the problem of the water content in the emission, we need to get the position where the water vapor takes liquefaction. In that part the exhaust pipe temperature is about 100℃. This can provide a theoretical basis to design a new type of exhaust pipe which can solve this dripping problem in winter and prevent its impact on the traffic environment.This paper is mainly about the research on the internal temperature distribution of exhaust pipe from the ethanol gasoline vehicles when they are traveling in cold weather. This paper has talked about the ethanol's usage in both domestic and foreign countries and its development and trends, and also some relative references researching on exhaust pipe. Then taking the winter in Harbin as experimental area and measure the internal temperature of the exhaust pipe of the ethanol gasoline vehicle and the water received from the tail pipe, which is carried on in winter(Jan.30th,31st,Feb.1st; Temperature-10℃) and spring (Apr.29th,30th;22℃) of 2008. This paper has introduced the basic theory of simulation and CFD software FLUENT. On the basis of computational fluid dynamics, a computation model is established to study the automotive exhaust system with the application of FLUENT, so as to get the internal temperature distribution. And use the experiment data to test the experimental validation of numerical simulation.