The Simulations of Diesel Engine Spray Combustion and Two Phase Flow Field

• Main Authors: Chong-de Chang, 張崇德
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/14810446725937970717

碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 93 === This research applied the KIVA-3V (Release 2) 3-Dimentional Reactive Flow Code developed by USA Los Alamos National Laboratory on the diesel engine combustion phenomena. The preprocessor (K3prep) constructs the grids on the intake manifold, the cylinder chamber, the bowl on piston surface, and the exhaust manifold. The experimental measured engine geometry data and engine operating conditions are then converted into the input file (itape 5). With the various adjustments on these input data, the diesel engine combustion performance is simulated under the three-dimensional bases. The baseline case is set on 1800 rpm engine speed and equivalence ratio ��=0.25 engine load. The engine operating conditions are then changed to higher engine speeds and engine loads. The simulated cylinder pressures and heat release rates are compared to the experimental results to understand its simulation characteristics. The dynamic out put (0~720 CA) is post processed by K3POST Code and the Tecplot software. The flow streak line, the pressure filed, the temperature distribution and the droplet relative locations inside the cylinder chamber are first studied at several key crank angles. Then the various gas concentration (NOx, HC, CO, CO2 ) and the turbulent kinetics distribution are then displayed in sequential crank angles. The KIVA-3V results show the acceptable similarity of the cylinder pressures and heat release rates between simulation and experimental works. The chemical reactions and flow field inside the cylinder are demonstrated in 3-D continuous graphics. This study helps to have powerful insight into the non-measurable phenomena inside the diesel engine.