摘要
在分配集箱中取微元控制体，通过建立质量守恒方程和动量守恒方程，明确了参数Ｃｆ的物理意义。依据Ｃｆ取值范围，描述了分配集箱静压分布和动量交换控制为主、动量交换与摩擦阻力竞相影响、摩擦阻力控制为主３种情形与Ｃｆ的关系，理论分析与前人试验结果相吻合。同时，对采用我国水动力计算标准方程给出的Ｃｆ＝１．２４计算分配集箱静压分布时，给出了分配集箱长径比的限制。不同的长径比，集箱内静压分布呈现动量交换控制或动量交换与摩擦阻力竞相影响两种不同情形。在动量控制区，不同结构的集箱，有不同的Ｃｆ值。
Based on building the mass balance equition and momentum conservation equition of micro control unit of distributing headers, this paper presents the physical characteristics of the parameter C f. In accordance with this parameter, the hydrostatic pressure distribution of distributing header is divided into three items: a). when C f≤2-λL2D , momentum dominates, the hydrostatic pressure will increase with the length of headers; b). when 2-λL2D[SX)]<C f<2, momentum effect balances friction, the hydrostatic pressure will decrease, then increase; c). when C f ≤2, friction dominates, the hydrostatic pressure will decrease, and be negative. The theoretical analyses are accordant with experimental results. When it is controlled by momentum trasfer, the hydrostatic pressure distribution parameter C f varies (C f =1.24) with structure of distributing headers.
出处
《动力工程》
CSCD
1997年第3期26-31,共6页
Power Engineering
