난류 예혼합 화염의 평균방향벡터와 평균곡률에 대한 수치적 연구

Abstract

Transport equations are derived for the mean orientation vector, ⟨⟩, and the mean curvature, ⟨∇·⟩, in turbulent premixed flames based on conditional average. Balance among all component terms is checked to understand their physical implications with the results of direct numerical simulations for three test flames. The terms involving tangential gradient and fluctuation of the sum of normal convective velocity and displacement speed are dominant to determine the mean orientation vector through a flame brush and at the leading edge. The tangential Laplacian term becomes important at the edges and different trends are observed on the dominant terms for thicker flamelets with the Karlovitz number greater than unity. Further study may be required to show the relative importance of the component terms for realistic flames in diverse combustion regimes.