Fluid-solid Interaction Of Centrifugal Pump And Experimental Analysis Based On Whole Flow Field

With the expansion of the centrifugal pump’s working range, the requirements of modern engineering and technology on centrifugal pump’s performance has become higher and higher. The centrifugal pump not only has high efficiency and strong adaptability to varying conditions, but also requires compactness and high reliability of the structure. So during the design of the centrifugal pump, it is necessary to take its flow characteristics into account to reach high efficiency, and to take the stability of the rotor structure and operation reliability into account. In this paper, firstly taking centrifugal pump impeller as object, using fluid-structure coupling theory, numerical simulation and test verification methods to get the whole flow field’s internal and external characteristics of multi-operating condition of the centrifugal pump, and the external characteristics got the test validation. Static analysis and modal analysis of the rotor system were conducted by ANSYS Workbench platform in order to obtain the structural characteristics of the rotor system, and got the first critical speed of the rotor system, so that the centrifugal pump could miss its critical speed to avoid resonance at runtime.Firstly, the modal analysis of the centrifugal pump impeller was simulated and the distribution of the first six vibration modes of the impeller was obtained. And the experimental modal analysis was conducted to verify the reliability and applicability of the simulation method. Then this simulation method of impeller was applied to the entire rotor system. In order to analyze the static structural and modal of centrifugal rotor system under pre-stress, firstly, the three-dimensional whole flow field of the centrifugal pump was simulated, including three-dimensional fluid domains’ establishment by Pro/e, grids’ division by ICEM, numerical simulation and of the flow field by CFX, post-processing of flow field by CFD Post, etc., and then got the internal and the external characteristics of the centrifugal pump. The experiment of centrifugal pump was conducted to verify the correctness of the numerical simulation of the external characteristics. Next, the three-dimensional solid domains of rotor system were created and meshed, and applied the field pressure to the structure to analyze the static structural and modal of rotor system, getting the distribution of the stress, deformation and vibration type. Besides, the influence of different flow on the rotor system’s stress and deformation had been analyzed, and from the fourth strength theory for checking the strength of the most dangerous conditions rotor system, we can see the structure at runtime is safe and reliable. In addition, superposition method and finite element method were used to calculate the first critical speed of the rotor system, the result achieved by finite element method was greater than the superposition method, the relative error between the two results is 2%. So, in order to get the stable operation of the rotor system, the more secure way is to select the smaller result of the two methods as the first critical speed value in practice.