以液体乙醇为燃料,采用内径为1.0 mm的陶瓷管作为燃烧器,并通过在陶瓷管外放置内径为8.8mm的透明玻璃管形成受限空间,进行了受限射流扩散燃烧与自由射流扩散燃烧的对比实验研究,并对稳定燃烧情况下的火焰结构进行了光学可视化测量.结果表明：自由射流扩散火焰呈椭球状,受限射流扩散火焰呈圆锥状;在相同的乙醇流量下,受限射流扩散火焰的长度和宽度均小于自由射流扩散火焰;受限射流扩散燃烧时燃料和空气的混合效果要好于自由射流扩散燃烧,而且其火焰结构受浮升力的影响较大.

 Comparative experiments between small-scale free jet diffusion combustion and the confined jet one were performed from a circular ceramic burner with the inner diameter of 1.0mm,using liquid ethanol as the fuel.A transparent glass tube with an inner diameter of 8.8mm was put outside the ceramic tube to form a confined space.The structure of the flames in steady combustion was then measured with optical visualization method.The results indicate that the free jet diffusion flames are ellipsoidal while the confined ones are tapered,that the length and width of confined jet diffusion flames are both less than those of free jet flames at the same ethanol flowrate,that the mi-xing of fuel and air in confined space is better than that in free space,and that the structure of confined jet di-ffusion flames is more sensitive to the buoyancy.