Atomization Performance of an Internal-Mixing Nozzle with Singularity Structure

• Main Authors: Ying-Ren Tseng, 曾瑛仁
• Other Authors: Muh-Rong wang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/83342827686690312274

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 92 === 　　This research program investigates the atomization characteristics of the internal mixing atomizer under different design configurations. The design parameters include the orifice diameter, the swirler and the center body, etc. The atomizers are designed P-type atomizers (i.e., P-1、P-2、P-3 atomizers) and N-type atomizers (i.e., N-1、N-2、N-3 atomizers). The effects of these design parameter on the atomization performance are described. Malvern RT-Sizer measures the particle size of the spray. 　　Results show that P-type atomizer with large orifice area produces spray with fine particle size and narrow size distribution. As a typical example, spray with (SMD, σ)=(4.68,16.93) μm can be obtained using P-1 atomizer under a liquid pressure of 3.0bar and gas pressure of 4.5bar. Furthermore, (SMD, σ)=(3.52, 8.54)μm and (SMD, σ)=(3.00, 5.69)μm can be aliened P-2 and P-3 atomizers, respectively. The enhanced atomization performance by increasing orifice area is due to the increase in gas-to-liquid mass ratio. 　　Results also show that the N-1 atomizer with center body has better performances than N-2 and N-3 atomizer. This indicates that the atomizer with center body can produce fine droplets and narrow size distribution. The atomizer with longer swirling chamber degrades the atomization performance. As a typical example, spray with (SMD, σ)=(3.77, 9.58)μm can be achieved using N-1 atomizer under liquid pressure of 3.0bar and gas pressure of 4.5bar. The cases of N-2 and N-3 atomizer (SMD, σ)=(4.03, 10.62)μm, (SMD, σ)=(4.76, 19.56)μm respectively. Hence the design of atomizer with center body can be used to enhance the atomization performance.