紊流調制項中不對稱交互相關函數之成因研究

The Study of Asymmetric Distribution of Cross-Correlation Function of Turbulence Modulation

呂偉福(Wei-Fu Lu) ； 賴維祥(Wei-Hsiang Lai) ； 張克勤(Keh-Chin Chang) ； 蔡東曉(Tung-Hsiao Tsai)

《航空太空及民航學刊.系列B》 40卷1期 (2008/04) Pp. 21-26

https://doi.org/10.6124/JAAA.200804_40(1).03

摘要

As reported in the study of Chang et al. (2003), the modulation of the carrier-phase turbulence, that is, the effect of the presence of dispersed phase on the turbulence structure, is heavily dependent on the term of (＜u'(subscript gi)u'(subscript pi)＞-2k). Nevertheless, very few experimental data of ＜u'(subscript gi)u'(subscript pi)＞ can be found in the literature. Wang and Huang (1995) made the ＜u'(subscript gi)u'(subscript pi)＞ measurements by using a phase Doppler anemometer in a planar mixing-layer flow leaded with polydispersed spray. However, the accuracy of the measured ＜u'(subscript gi)u'(subscript pi)＞ data made by Wang and Huang was in doubt according to the comparison results with the model predictions in the study of Chang et al. Tsai (2003) found that Wang and Huang overestimated the turbulence modulation quantity in the shear layer in the downstream regions, and the symmetric assumption of cross-correlation function is unavailable for large particles (30μm). Lu et al. (2006) found that the ＜u'(subscript gi)u'(subscript pi)＞ term and ＜u'(subscript pi)u'(subscript gi)＞ term are also different besides asymmetric graph of cross-correlation function by using a Particle Doppler Analyzer in a turbulence field with 70 μm monodispersed droplet. This paper will discuss the reason for this.

關鍵字

紊流調制 ； 交互相關函數 ； 兩相流

並列摘要

As reported in the study of Chang et al. (2003), the modulation of the carrier-phase turbulence, that is, the effect of the presence of dispersed phase on the turbulence structure, is heavily dependent on the term of (＜u'(subscript gi)u'(subscript pi)＞-2k). Nevertheless, very few experimental data of ＜u'(subscript gi)u'(subscript pi)＞ can be found in the literature. Wang and Huang (1995) made the ＜u'(subscript gi)u'(subscript pi)＞ measurements by using a phase Doppler anemometer in a planar mixing-layer flow leaded with polydispersed spray. However, the accuracy of the measured ＜u'(subscript gi)u'(subscript pi)＞ data made by Wang and Huang was in doubt according to the comparison results with the model predictions in the study of Chang et al. Tsai (2003) found that Wang and Huang overestimated the turbulence modulation quantity in the shear layer in the downstream regions, and the symmetric assumption of cross-correlation function is unavailable for large particles (30μm). Lu et al. (2006) found that the ＜u'(subscript gi)u'(subscript pi)＞ term and ＜u'(subscript pi)u'(subscript gi)＞ term are also different besides asymmetric graph of cross-correlation function by using a Particle Doppler Analyzer in a turbulence field with 70 μm monodispersed droplet. This paper will discuss the reason for this.

並列關鍵字

Turbulence modulation ； Cross-correlation function ； Two-phase flows