Intracellular Flow Filed Simulation By Finite Element Method During Cytokinesis

In this dissertation,the finite element model was established for the intercellular bridges thinning and the deformation of daughter cells during cytokinesis,and analyzed the changes of intracellular flow field and pressure field.Firstly,the daughter cell and nucleus were built into a sphere model using the Design Modeler software in ANSYS-workbench software and the intercellular bridge connecting the two daughter cells was built into a cylindrical channel model by using this software.Using Meshing software to divide the grid;The finite volume method was used and the boundary condition of daughter cells was set as no slip boundary.The thinning of the intercellular bridge along the radius was set and it causes the cytoplasmic flow from the intercellular bridge to the daughter cells.A dynamic mesh method was used to control intercellular bridges thinning,position and deformation rate of blebs.Secondly,Fluent software was used to calculate the flow velocity distribution,pressure distribution and fluid force on the nucleus,and analyzed the effect of intercellular bridge deformation and daughter cell expansion.Finally,the characteristics of velocity and pressure distribution were analyzed by simulating the process of blebbing deformation in daughter cells.The simulation results were compared with the experimental results to verify the rationality and effectiveness of the model.The contents of this dissertation are as follows:1.The finite element model of cytokinesis was established to simulate the thinning of intercellular bridge ? daughter cell expansion and daughter cell bubbling.The simulation results of blebbing deformation of daughter cells provide the basis for subsequent simulation,experiment and data analysis.2.Cytoplasmic flow at intercellular bridges and blebs in simulation and experimental conditions were compared.The results showed that the different positions of daughter cell blebs led to different outlet velocity.In addition,the difference of cytoplasmic velocity between deformable and non-deformable regions was consistent with the results of simulation and experiment.The simulation results provide the foundation for the following simulation,experiment and data analysis.3.By simulating the effect of daughter cell expansion and blebbing on intracellular pressure distribution,the role of deformation of daughter cell in stabilizing intercellular bridges and nucleus was analyzed.