从不同层次上研究了循环流化床颗粒相的湍流结构。PDA测量发现颗粒在壁面附近的运动表现出显著的成团特征和湍流度显著降低,小波分析法得到的直观图形象地揭示了颗粒速度脉动的自相似、分叉等具有混沌特征的微观结构,且在不同的尺度上颗粒速度脉动表现出各向异性的特征。
Turbulence structures of solid phase in a circulating fluidized bed were (CFB)characterized. The investigations were carried out using a Particle DynamicAnalyzer (PDA). Temporal evolutions of the particle velocity fluctuationindicate that the great agitation and non-homogeneity with time and spacecoordinate of the solid phase. The studies on turbulent density illustratethat the turbulence in the CFB is an anisotropic turbulence, and the particleturbulent density decreased sharply as the measurement points move away fromthe wall. To further understand the microstructure of the particle velocityfluctuation, wavelet analysis was also adopted. The vivid imagines show thatit is an anisotropic turbulence at all scales and its fractal and dissipativestructure.
参考文献
[1] | Bai D.;Masuda Y.;Nakagawa N.;Kato K.;Shibuya E. .FLOW STRUCTURE IN A FAST FLUIDIZED BED[J].Chemical Engineering Science,1996(6):957-966. |
[2] | Wang T;Lin Z J;Liu D C .Particle Velocity Measurements in aCirculating Fluidized Bed[J].AICHE Journal,1993,39(08):210-214. |
[3] | Van den Moortel T.;Santini R.;Tadrist L.;Azario E. .Experimental analysis of the gas-particle flow in a circulating fluidized bed using a phase Doppler particle analyzer[J].Chemical Engineering Science,1998(10):1883-1899. |
[4] | 崔锦泰.小波分析导论[M].西安:西安交通大学出版社,1995 |
[5] | 周浩生;陆继东 .循环流化床稀相区流动结构实验研究[J].燃烧科学与技术,1998,4(04):391-395. |
[6] | 周浩生 .循环流化床气固两相流动结构与氮氧化物控制机理[R].武汉:华中理工大学,1999. |
[7] | Argoul F;Arneodom A .Wavelet Analysis of Turbulence Reveals theMulti-Fractal Nature of the Richardson Cascade[J].Nature,1989,338(02):51-53. |
- 下载量()
- 访问量()
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%