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对9种弯径比的8 mm直径90°弯曲圆管,在7种雷诺数条件下的流动过程进行了数值实验研究,得到了弯管内流动的压力和速度分布以及局部阻力系数同弯径比和雷诺数之间关系的经验公式。结果表明,压力和速度在弯头部分沿轴线呈非线性分布,且随雷诺数增大非线性更加明显,而且这种非线性所表现出的压力损失是由于压力在弯头部分内、外壁面不一致分布造成的二次流所引起;同时,凝胶推进剂在弯管内流动的最大速度点出现在靠近弯管外壁,且沿着流动方向和流动速度的增大,最大速度点的偏离更加明显。因此,对于小雷诺数条件下的凝胶推进剂流动,需关注弯管内壁可能出现的胶凝剂沉降现象。
Nine kinds of bending radius tube with 90 mm radius and 90 ° bending radius were studied numerically under seven kinds of Reynolds number conditions. The pressure and velocity distribution of the flow in the elbow and the relationship between the local resistance coefficient and the radius of curvature Empirical formula of the relationship between Reynolds number and Reynolds number. The results show that the pressure and velocity are non-linearly distributed along the axis of the elbow, and the non-linearity increases with the Reynolds number. The pressure loss caused by this nonlinearity is due to the pressure in the elbow section, Caused by the secondary flow caused by inconsistent distribution; the same time, the maximum velocity of gel propellant flow in the elbow appears near the outer wall of the elbow, and along the flow direction and the flow rate increases, the maximum velocity point deviation more obvious. Therefore, for the flow of gel propellant under the condition of small Reynolds number, attention should be paid to the possible settlement of gelling agent on the inner wall of elbow.