扩散火焰受横向直流电场淬熄数值模拟与实验研究

Numerical simulation and experimental study of quenching of diffusion flame subjected to transverse DC electric field

为研究横向电场对火焰及其周围流场的影响,通过ANASYS Fluent软件模拟流量0.005 kg/s、出口速度20 m/s、高度约50 cm的乙醇-空气扩散火焰受电场强度50 kV/m横向电场的影响,对燃烧场内带电粒子受电场力出现移动及其产生的离子风现象进行了数值模拟,复现了火焰受电场影响出现的淬熄现象。将仿真计算得到的燃烧区域内温度、流场及压力分布与实验过程中拍摄的火焰可见图像及所测数据进行比较,验证了该数值模型的有效性。研究结果表明:该模型能够在横向电场条件下定性再现改变火焰行为的能力,证明了离子风效应对火焰动力学的影响,可为电场灭火技术的研发提供理论支撑。

In order to study the influence of transverse electric field on the flame and its surrounding flow field,the ethanol air non premixed diffusion flame with flow rate of 0.005kg/s,outlet speed of 20m/s and height of about 50cm was simulated by ANSYS Fluent software.The charged particles in the combustion field move under the electric field force and the phenomenon of ion wind was numeri-cally simulated.The three experimental phenomena of combustion promotion suppression quenching of flame with the increase of electric field intensity were reproduced.The temperature,flow field and pressure distribution in the combustion area calculated by the simulation were compared with the visi-ble flame images and measured data taken in the experimental process to verify the effectiveness of the numerical model.The results prove that the proposed model can qualitatively reproduce and change the flame behavior under the condition of transverse electric field,and prove the influence of ion wind effect on flame dynamics,which can provide theoretical support for the research and development of e-lectric field fire extinguishing technology in the future.