相似理论在渣浆泵中的应用描述和计算
    由于液体在离心泵中的流动过程十分复杂，很难依靠理论方程来描述和计算，一般多采用试验的方法进行研究，因此需要使用流体力学中的相似原理来指导试验并把试验结果应用到实际问题中。相似原理为离心泵的相似设计、试验研究和性能换算等方面提供了可靠的理论依据。
一、离心泵相似条件
    要保证液体在两泵中流动相似，必须满足两泵几何相似、运动相似和动力相似。在本节论述过程中，将两台要进行性能换算的离心泵分别称为模型泵和原型泵，并用右上角打撇的参数表示模型泵的参数。

(1)几何相似。几何相似是指模型泵和原型泵通流部分的几何形状相似，即对应的线性尺才之比等于比例常数A.(a. = D:/D.也称比例缩放系效)，对应的叶片几何角和叶片数均相等。
    (2)运动相似。运动相似是指流体在泵内流动过程中.两泵的对应点上同名流动速度的比值相等，并等于速度比例常数λ.同时同名速度的方向角也相等。
    (3)动力相似。动力相似是指两泵对应点上作用的同名力之比相等，并等于力比例常数不，同名力的方向相同。对离心泵而言，不需要所有的力之比都相等，仅保证黏性力和惯性力之比相等即可，即两泵的雷诺数Re相等就是动力相似的充要条件。因为离心泵中雷诺数一般大于105,此时流动阻力和运动状况已不随Re而变化，自动满足动力相似的要求。渣浆泵
    因此，对Re>105的两泵的相似条件是:几何相似和进口运动相似。符合上述相似条件的泵称为相似泵。

Application description and calculation of similarity theory in slurry pump

Because the flow process of liquid in centrifugal pump is very complex, it is difficult to describe and calculate by theoretical equation. Generally, experimental method is used to study, so it is necessary to use the similarity principle of hydrodynamics to guide the test and apply the test results to practical problems. The similarity principle provides a reliable theoretical basis for similar design, experimental research and performance conversion of centrifugal pump.

1、 Similar conditions of centrifugal pump

In order to ensure that the flow of liquid in the two pumps is similar, it is necessary to meet the geometric similarity, motion similarity and dynamic similarity of the two pumps. In this section, the two centrifugal pumps to be converted are called model pump and prototype pump respectively, and the parameters of model pump are represented by the parameters of skimming in the upper right corner.

(1) Geometric similarity. Geometric similarity refers to the geometric similarity of the flow passage parts of the model pump and the prototype pump, that is, the ratio of the corresponding linear scale is equal to the scale constant A. (A. = D: / d. also known as the scale factor effect), and the corresponding blade geometric angle and blade number are equal.

(2) Movement is similar. Motion similarity refers to the fact that the ratio of the flow velocity of the same name at the corresponding point of the two pumps is equal, and it is equal to the velocity ratio constant λ. At the same time, the direction angle of the same name velocity is also equal.

(3) Similar dynamics. Dynamic similarity refers to the fact that the ratio of the forces acting on the corresponding points of two pumps with the same name is equal and equal to the constant of the force proportion, and the direction of the forces with the same name is the same. For centrifugal pumps, it is not necessary to make the ratio of all forces equal, only to make sure that the ratio of viscous force and inertia force is equal, that is, the Reynolds number Re of the two pumps is equal, which is the necessary and sufficient condition for the dynamic similarity. Because the Reynolds number in the centrifugal pump is generally greater than 105, the flow resistance and the motion state do not change with Re, and automatically meet the requirements of dynamic similarity. Slurry pump

Therefore, the similarity condition of two pumps with re > 105 is that the geometry is similar to the inlet motion. The pumps that meet the above similar conditions are called similar pumps.