薄片型壓力渦漩式霧化器流場之數值研究

Numerical Study of Flow in Macrolaminated Pressure Swirl Atomizer

曾培元(P. Y. Tzeng) ； 劉中和(C. H. Liu) ； 朱裕瑞(Y. J. Chu)

《中國航空太空學會學刊》 35卷2期 (2003/06) Pp. 175-183

https://doi.org/10.6124/TAASRC.200306_35(2).08

摘要

本文目的在於運用數個法建立薄片型壓力渦漩式霧化器之模擬能量，採用三維單相流並擴展計算域至外流湯，結合紊流動能(TKE)及軸向速度分佈特性，共同描述「擬空氣紋」(Air-Core-Like)之特徵，發現當此特徵區擴展時，其平均液滴粒徑(SMD)與噴霧錐角隨之增長，於探討分析噴孔內部流場特性及渦旋室軸徑(L(下標 s)/D(下標 s))對流場特性之影響，當增加其比值(0.009~0.322)發現增厚渦旋室之霧化器，可獲得較高的TKE值分佈特性，並藉此預測噴霧錐角與SMD值將隨之減小；因此TKE分佈特性與噴霧錐角須依撼設計要求而有所取捨。本研究結合TKE及軸向速度分佈特性所闡述之分析模式，有助於瞭解薄片型壓力渦漩式霧化器之重要幾何參數對其噴霧效果的影響趨勢，可作爲設計改進之參考。

關鍵字

薄片型霧化器 ； 壓力渦漩式霧化器 ； 平均噴霧粒徑 ； 紊流動能

並列摘要

The objective of this research is to develop a practical single-phase flow simulation capability of the macrolaminated pressure swirl atomizers flow field by using the numerical method, and expanding to 3-D calculation domain including outer flow field. The velocity and turbulence kinetic energy (TKE) profiles at the orifice exit are used to describe the features of air-core-like region. The broadening of this region would lead to the increase of Sauter Mean Diameter (SMD) and spray cone angle. The effects of swirl chamber length to diameter ratio (L(subscript s)/D(subscript s)) on the flow characteristics in the exit region are also examined. Increasing the ratio (0.119 to 0.322) would result in the TKE increasing and the spray angle decreasing, which may be related to the decrease of SMD. The results indicate that there must be a trade off between TKE profile and spray angle in design requirement. This research provides better understanding of how geometrical parameters affect the spray characteristics of the macrolaminated atomizers and may contribute to their design improvements.

並列關鍵字

Macrolaminated atomizer ； Pressure swirl atomizer ； Sauter mean diameter SMO ； Turbulent kinetic energy TKE