The present work describes the transition of transient one-dimensional diffusion flame into a steady two-dimensional regime in a new flow field configuration. To that end, a cylindrical burner from which fuel is ejected radially and uniformly is positioned in the middle of two impinging flows. The chosen conditions are such that the strain rate is very low. The majority of the flame is located in a region of the flow field where spatial coordinates are scaled with the reciprocal of the square root of the strain rate, and the velocities are scaled with the square root of the strain rate. To simplify the model, a potential flow is assumed, with its results compared with those from a more detailed incompressible Navier–Stokes flow solution. The evolution of the flame is similar in both cases, which shows that the idealised potential flow describes well the flow field in such a geometry. Mixture fraction and excess enthalpy variables are employed to describe the infinitely fast chemical reaction, and therefore, fuel mass fraction, oxidiser mass fraction, and temperature fields. Results show that the initial flame displacement is controlled by the radial transport of fuel near the burner, where the impinging flows have a negligible influence. After that region, the flame is strongly influenced by the impinging flows where its acceleration is observed. Moreover, the proposed asymptotic solutions highlight the main transport mechanisms of reactants to the flame under different conditions and show the dependence of the flame on the chemical and flow field parameters. The stationary solution presents a diffusion flame with continuous geometric variation, from the counterflow to the coflow regime.

目前的工作描述了在新的流场配置中瞬态一维扩散火焰向稳定二维状态的转变。为此，在两个撞击流的中间放置了一个圆柱形燃烧器，从中径向均匀地喷射燃料。选择的条件是应变率非常低。大部分火焰位于流场区域，其中空间坐标与应变率平方根的倒数成比例，速度与应变率的平方根成比例。为了简化模型，假设潜在流，并将其结果与更详细的不可压缩 Navier-Stokes 流解的结果进行比较。两种情况下火焰的演变是相似的，这表明理想化的势流很好地描述了这种几何结构中的流场。混合分数和过量焓变量被用来描述无限快的化学反应，因此，燃料质量分数、氧化剂质量分数和温度场。结果表明，初始火焰位移受燃烧器附近燃料的径向传输控制，其中撞击流的影响可以忽略不计。在该区域之后，火焰受到撞击流的强烈影响，在那里观察到其加速。此外，所提出的渐近解突出了不同条件下反应物向火焰的主要传输机制，并显示了火焰对化学和流场参数的依赖性。