Numerical Calculation And Analysis About The Flow Field Of Centrifugal Cardio Pump

Computational Fluid Dynamics (CFD) as a powerful tool for numerical simulation can compare two cardio pump modles, which are designed by unitary theory with recirculation region and the other cardio pump with anti-recirculation region, and the flow inside the pump is analyzed, the peculiar flow pattern in the impeller along the flow path is revealed.Simulation can get the shear stress distribution , the velocity distribution and the pressure distribution in the impeller along the flow path , compared the influence of thrombus and hemolytic in the cardio pump with recirculation region and the other cardio pump with anti-recirculation region , and improved the performance in the anti-thrombus and hemolytic.1. According to the development and problems of cardio pump, based on N-S equation , elaborated CFD basic theory, analyzed models and numerical value methods at the process of simulation.2. Unitary theory is used to the hydraulic design of the cardio pump, Pro/E is used to build physical model ,then it is guided into ICEM to created flow region, unstructured grid is used to divide the flow region , elaborated the influence of the grid.3. The mesh file is guided into the fluid simulation software FLUENT,the fluid parameter and boundary conditions is set,the RNG k ?εturbulent model and pressure coupling arithmetic to solve the equation and calculate flow field of the cardio pump.4. The simulated result under the same boundary conditions displayed the velocity distribution and the pressure distribution accord with the theoretical studies inside the cardio pump, in addition to the velocity distribution and the pressure distribution in the recirculation region is better than the anti-recirculation region.5. Both pumps appeared eddy current on the middle part of the working surface, and the cardio pump with anti-recirculation region is lower than the cardio pump with recirculation region.6. Compared the shear stress distribution can conclude the maximum shear stress in the cardio pump with the recirculation region is lower than the pump with the anti-recirculation region and the region of the shear stress is exceed the critical shear stress(150Pa) which produced hemolytic is less than the cardio pump with the anti-recirculation region.As a result it cause a tiny destroy to the blood cell and the pump with the anti-recirculation region model correspond with the demand of the hemodynamic.