Fluid Solid Interaction Numerical Simulation Of Three-dimensional Cell Scaffolds With Three Different Structures

Cells in the microenvironment are subject to various forms of mechanical stimulation,which directly affects its physiological activities.As an important part of tissue engineering in vitro,three-dimensional cellular scaffold provides a stable and suitable living space for cell culturing and constructing.Therefore,by studying the mechanical response of cell scaffolds in fluid under various conditions and the parameters of flow field around scaffolds,we can provide basis and reference for cell culture in tissue engineering in vitro.Based on the theoretical basis of fluid mechanics and solid mechanics,numerical simulations of three-dimensional cell scaffolds with three different structures in perfusion bioreactors are carried out in this dissertation by using ANSYS Workbench software for fluid solid interaction.By varying the filament diameter of the 3D cell scaffold and the inlet velocity of the fluid,the effects of filament size and inlet velocity on the mechanical response of the scaffold and the changes of the flow field parameters in the fluid solid interaction numerical simulation are also investigated in this dissertation.Under a certain fluid inlet velocity,the increase of the stent filament diameter leads to a more uniform shear stress distribution on the wall of the stent and a decrease of the equivalent effect force and equivalent effect variation.When the fluid flows through the stent area,the velocity of the fluid increases significantly and with the increase of the stent filament diameter.The greater the increase in velocity,the greater the diameter of the stent filament also leads to an increase in shear stress and pressure at the solid-liquid interface.The fluid pressure at the solid-liquid interface decreases rapidly along the direction of fluid flow.By comparing the mechanical response of 3D cells scaffolds with different structures,the author find that the octagonal cellular element scaffold is least affected by the filament diameter change.The wall shear stress distribution of their scaffolds was the most uniform for the same inlet velocity.After studying the effect of filament diameter,this dissertation investigates the changes of fluid inlet velocity on the mechanical response of the stent and flow field parameters in the flow-structure coupled numerical simulation.After comparative analysis,it is found that when the inlet velocity increases,the wall shear stress distribution of the stent becomes uneven,and the equivalent force and equivalent variation increase.The increase of inlet velocity leads to the increase of fluid inlet pressure and pressure gradient at the fluid-solid-liquid interface.By comparing the mechanical response of 3D cell scaffolds with different structures,the author find that the octagonal cytosolic scaffold is least affected by the inlet velocity.The wall shear stress distribution of their scaffolds is the most uniform for the same scaffold filament diameter.In conclusion,the study of the mechanical effects of different factors on threedimensional cell scaffolds and fluids in perfusion bioreactors can provide a reference for the selection of in vitro cell culture scaffolds and the flow rate control of culture fluid.This plays an important role in promoting the development of in vitro tissue engineering.