http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
SI 엔진에서 Fractal Geometry를 이용한 난류 연소 모델
홍명석,손정배 조선대학교 에너지.자원신기술연구소 1998 에너지·자원신기술연구소 논문지 Vol.20 No.2
Use of fractal geometry to model the effects of turbulence on flame propagation in an engine is explored using a quasidimensional, 4-stroke, homogeneous charge, SI engine code. Various assumptions are made in the model formulation to allow this technique to be investigated as expeditiously as possible. Model predictions are compared to experimental data from an engine with an axisymmetric pancake-shaped combustion chamber. The sensitivity of the model predictions to the fractal dimension, to the effects of flame stretch, and to the ratio of maximum-to-minimum flame wrinkling scales is invested. It is shown that the predicted initial rate of pressure rise is a strong function of fractal dimension but is relatively insensitive to the flame wrinkling scales or the effects of stretch over the ranges of these parameters expected for the engine application. This model and a modification of this model appear to be reasonable and yield values for the fractal dimension which agree with the limited experimental engine data avaliable. It is shown that flame stretch is dominated by flame strain and decrease throughout the combustion process. By allowing the maximun flame wrinkling scale to be equal to the instantaneous flame radius, the correct trend of the turbulent flame speed is predicted. The model results that the use of fractals to model turbulent combustion is an important new tool for engineering design.