采用离子电流法测量火焰厚度的研究

Measurement of Flame Thickness by Ion Current Method

在定容燃烧弹上，运用离子电流法，测量了CH4及其掺氢混合气在不同工况下燃烧的离子电流信号，给出了燃烧火焰的前锋面厚度的计算方法，并与已有文献结论进行对比验证，结果表明，对于 CH4/空气混合气预混层流燃烧，利用离子电流法测得的前锋面火焰厚度在空燃比为0.75、0.80、0.85、0.90、1.00和1.10时分别为1.337mm、1.316mm、1.273mm、1.260mm、1.309mm、1.353mm；在空燃比为0.8、掺氢比0-80%,（10%,递增）时测量结果分别为1.456mm、1.371mm、1.216mm、1.111mm、1-062mm、0.951mm、0.857mm、0.871mm 和0.818mm．该结果变化规律均与已有文献结论一致，表明利用离子电流法测量层流火焰厚度以分析火焰稳定性具有较高的可行性，离子电流法不仅能够测量火焰速度，同时还能够在线得出火焰厚度．

The ion current method was used to obtain the flame thickness of CH4/hydrogen mixture under different operating conditions,the calculation method for flame thickness was established,the experimental conclusions were compared with those of references. The results show that for the CH4/air mixture,at the excess air ratio of 0.75, 0.80,0.85,0.90,1.00,1.10,the flame thickness measured by the ion current method was 1.337mm, 1.316mm,1.273mm,1.260mm,1.309mm,1.353mm,respectively. At the excess air ratio of 0.8,whenthe hydrogen fraction was 0—80%（10% increment）,the flame thickness of CH4/hydrogen mixture was 1.456mm, 1.371mm,1.216mm,1.111mm,1-062mm,0.951mm,0.857mm,0.871mm,0.818mm,respectively. The results show good agreement with those of previous research work,indicating that it is possible to evaluate the flame stability utilizing the thickness of laminar flame obtained by ion current method. Both flame speed and flame thickness can be obtained by ion current method.