基于数字图像处理的LPG喷雾特性试验研究

Experimental Study of LPG Spray by Using Digital Image Processing Techniques

使用高速纹影摄影和数字图像处理方法研究了具有相同喷孔直径的两个分别带有和不带双孔分流套的单喷孔喷嘴在MPI喷射条件下液态LPG燃料的自由喷雾过程,测量了喷雾贯穿距离、投影喷雾面积、喷雾体积和喷雾锥角等喷雾特性。通过与手工测量结果对比证明了数字图像处理方法测量结果的有效性。试验结果表明:喷射压力越高,喷雾贯穿距离、投影喷雾面积和喷雾体积越大,而喷雾锥角越小;带有双孔分流套的喷嘴雾化效果好,更有利于形成均匀混合气;在喷雾中期和后期,不带双孔分流套的喷嘴的喷雾贯穿距离长,但在喷雾初期的一段时间内,却比带有双孔分流套的喷嘴的喷雾贯穿距离短。

The characterization of LPG spray for two single-nozzle injectors in same nozzle diameter with and without double-hole flow split head is investigated by using schlieren photography and digital image processing techniques. The image processing procedure is proved to be accurate and efficient by comparing the spray tip penetration distances with those obtained from manual method. Spray parameters including spray angle, projected spray area and spray volume are measured using the digital method for both injectors. The results show that high injection pressure increases spray tip penetration distance, projected spray area and spray large volume but decreases spray cone angle. The LPG spray injected from the injector with double-hole flow split head makes good atomization but has shorter tip penetration distance in intermediate and late spray developing stages but gives fast spray development at initial stage.