Investigation on Particle Dispersion in Pulsing Jet Using Vortex Method

以渦流法探討微粒子在間歇噴流之擴散

王健彰(Chien-Chang Wang) ； 洪振益(Chen-I Hung)

《中國機械工程學刊》 32卷2期 (2011/04) Pp. 93-101

https://doi.org/10.29979/JCSME.201104.0001

摘要

本文採用渦流法模擬兩相平面噴流場，主要研究目的在於探討外加激擾對粒子擴散之影響。研究中使用縱向激擾以形成間歇噴流，模擬結果發現此種激擾方式可產生空間對稱性之渦偶結構，並且成功展現出渦流結構間之leap-frogging現象。此外，渦流結構的發展對粒子擴散亦具有深遠的影響；研究結果發現，基於間歇噴流中渦流結構的對稱性，使得粒子的分佈得以修正而具有對稱性。更近一步的發現，本文中St numeber最大的粒子(St=23.6)可藉由低頻激擾得到較佳的擴散變異量。

並列摘要

The evolution of particle dispersion in pulsing jet is simulated by the vortex method. The particles are traced using the Lagrangian approach. The objective of this study is to examine the effects of excitations on particle dispersion in the jet flow. In the present study, the longitudinal periodic disturbance is activated at the jet exit to form a pulsing jet. The results display spatially symmetric vortex structures, that can be generated periodically, and the leap-frogging process is also achieved successfully. In addition, the development of the vortex structures strongly influences on the particle dispersion. Results show that the symmetric particle distributions are obtained in pulsing jet attributed to the symmetric vortex structures. Furthermore, for the largest Stokes number (St=23.6 in this study), the particle dispersion process can be modified by this forcing type, and achieved a better dispersion variance using low-frequency disturbance.

並列關鍵字

vortex method ； pulsing jet ； leap-frogging phenomenon ； particle dispersion ； flow control