The effects of varying turbulence intensity and turbulence length scale on premixed turbulent flame propagation are investigated using Direct Numerical Simulation (DNS). The DNS dataset contains the results of a set of turbulent flame simulations based on separate and systematic changes in either turbulence intensity or turbulence integral length scale while keeping all other parameters constant. All flames considered are in the thin reaction zones regime. Several aspects of flame behaviour are analysed and compared, either by varying the turbulence intensity at constant integral length scale, or by varying the integral length scale at constant turbulence intensity. The turbulent flame speed is found to increase with increasing turbulence intensity and also with increasing integral length scale. Changes in the turbulent flame speed are generally accounted for by changes in the flame surface area, but some deviation is observed at high values of turbulence intensity. The probability density functions (pdfs) of tangential strain rate and mean flame curvature are found to broaden with increasing turbulence intensity and also with decreasing integral length scale. The response of the correlation between tangential strain rate and mean flame curvature is also investigated. The statistics of displacement speed and its components are analysed, and the findings indicate that changes in response to decreasing integral length scale are broadly similar to those observed for increasing turbulence intensity, although there are some interesting differences. These findings serve to improve current understanding of the role of turbulence length scales in flame propagation.

使用直接数值模拟 (DNS) 研究了不同的湍流强度和湍流长度尺度对预混湍流火焰传播的影响。DNS 数据集包含一组湍流火焰模拟的结果，这些模拟基于湍流强度或湍流积分长度尺度的单独和系统变化，同时保持所有其他参数不变。所有考虑的火焰都在薄反应区范围内。通过在恒定积分长度尺度下改变湍流强度，或通过在恒定湍流强度下改变积分长度尺度来分析和比较火焰行为的多个方面。发现湍流火焰速度随着湍流强度的增加以及积分长度尺度的增加而增加。湍流火焰速度的变化通常是由火焰表面积的变化引起的，但在高湍流强度值时观察到一些偏差。发现切向应变率和平均火焰曲率的概率密度函数 (pdfs) 随着湍流强度的增加和积分长度尺度的减小而变宽。还研究了切向应变率和平均火焰曲率之间相关性的响应。对位移速度及其分量的统计数据进行了分析，结果表明，积分长度尺度减小的响应变化与湍流强度增加时观察到的变化大致相似，尽管存在一些有趣的差异。