同轴旋转分层流燃烧器空气动力场的数值模拟

Numerical simulation on air dynamic field in co-axial swirling stratified flow burner

同轴旋转分层流燃烧器运用离心力分层原理,对一、二次风混合进行有效控制,达到分级燃烧,抑制NOx生成的目的。由于离心力的作用,同轴旋转分层流燃烧器的湍流脉动是各向异性的,这使得基于各向同性假设的k ε模型不再适用。本文运用作者提出的考虑离心力影响的k ε模型(k ε cf模型),对流项采用混合差分格式,对同轴旋转分层流燃烧器空气动力特性进行了数值模拟,将数值预报与实验测定进行了比较,得到了较好的结果。

The mechanism of stratification of centrifugal force is applied to a co-axial swirling stratified flow burner to control effectively the mixture between the primary and secondary air so as to attain staged combustion to prohibit yield of NO_x. Due to centrifugal force, air dynamic field in the burner is anisotropy, which makes k-ε taking model based on the hypothesis that a flow field is isotropic not suitable. k-ε-cf model proposed by the authors, a modified k-ε model taking centrifugal force into account, has been used in the present paper. Air dynamic field in a co-axial swirling stratified flow burner has been simulated with k-ε-cf model. The computational results agree well with the experimental data.