摘要
作者依据卡森方程及泊肃叶公式推导出卡森流体的流量公式为：Ｑｃ＝πＲ４ΔＰ８ηｃＬ（１－τｃτ）２。用同样方法导出滨汉氏流体的流量公式为：ＱＢ＝πＲ４ΔＰ８ηＢＬ（１－τＢτ）。对于其它非牛顿流体，只要能建立ηａ与ΔＰ（τ）之间的定量关系，均可代入泊肃叶公式得到该流体的流量公式。卡森流体修正因子（１－τｃτ）２与冈小天流量公式中的Ｆ（ξ）值不同，经实验验证（１－（τｃτ）２值与实验结果吻合，而Ｆ（ξ）值在γ＜２００ｓ－１时与实验结果有较大差距。修正因子有明确的物理意义，它是定量表示屈服值对流量及表观粘度影响程度的物理量。若以τｃ＝０时的流量（Ｑ０）及粘度（ηｃ）为准，则屈服值为τｃ时的流量（Ｑｃ）及ηａ符合下式：Ｑｃ／Ｑ０＝ηｃ／ηａ＝修正因子。该式为实验验证及获得修正因子提供了实验方法及理论依据。作者建议把修正因子作为血液流变学及血液动力学的定量指标。
he flow function of Casson fluid, which is deduced from Casson function and Poiseuille′s formula, is Qc=πR4ΔP8ηcL(1-τcτ)2. The flow function of Bingham′s fluid, which can be obtained by the same token is QB=πR4ΔP8ηBL(1-τBτ). As to other NonNewtonian fluids, as long as a quantitative relation between ηa and ΔP(τ) can be built, their flow formulas can be obtained by sustitute them into Poiseuille′s formula. The correction factor of Casson fluid (1-τcτ) differs from F(ξ). (1-τcτ)2 is identical with the experimental results, while there is a great gap between F(ξ) and the experimental results when <200s-1. Correction factor has a clear physical meaning. It quantitatively shows the degree that the volume of flow and apparant viscosity are affected by the shear rate. If we take the volume of flow (Q0) and ηc as a reference when τc=0,the volume of flow (Qc) and ηa follows the formula Qc/Q0=ηc/ηa=Correction factor, when the shear rate is τc0 The formula provides experimental method and theoretic basis for experimental verification and obtaining a correction factor. So the author suggests using correction factor as quantitative indices for Hemorheology and Hemodynamics.
出处
《北京生物医学工程》
1998年第3期173-177,共5页
Beijing Biomedical Engineering
关键词
卡森流体
滨汉氏流体
修正因子
泊肃叶公式
Casson fluid\ Bingham's fluid\ correction factor
\ Poiseuille's formular
