Finite Element Model Of Human Respiratory Tract And Numerical Simulation Calculation Of The Airway Local Contraction Flow

Asthma is a chronic respiratory disease, which is endangering human health and isbecoming a major problem. Especially in developing countries, including China, theincidence of momentum rising rapidly, mortality caused by asthma has also been agrowing, asthma caused worldwide economic losses have been more than the sum ofthe AIDS and tuberculosis caused economic losses. Etiology of asthma and itsdevelopment mechanism has yet to be fully cognitive.The pathological features of Asthma are the changes in the structure of the airwayand the airway hyper responsiveness to the contraction stimulus, meaning airwayremodeling and airway hyper responsiveness. The lung tube has very complexanatomical structures, including all branches of the changing diameter, length and othermorphological changes at all, under normal and pathological conditions, levels of theairway structure will occur on uneven shrinkage and expansion, resulting in airwaycomplex gas flow. Weibel, Horsfield have done a lot of research about anatomicalstructure of the human lung morphology and airway, but how to coupled complexairway geometry, airway flow with the changes of the airway wall, to establish thecomputational biomechanics model of the human respiratory system, to simulate airwaygas flow and mass transport are always challenging.Computational Fluid Dynamics (CFD) is a finite element analysis method, withsolving the Navier-Stokes (N-S) equation, which is putting the fluid, combustionprocess dispersed into microscopic scale basic on multiple hypothesis fluid equationsand the final simultaneous solution calculation process. The method is use of computerand the discretized numerical analysis method to simulate and analyze the fluidproblem.According the Horsfield, Tawhai respiratory airway model parameters, the paperuses AutoCAD, SolidWorks engineering software to establish of the theoretical modelof the human respiratory airway, then we import the theoretical model into COMSOLMultiphysics simulation system, simulate the contraction at G0airway local area,through changing the G0airway gas inlet velocity and the contraction of the innerblocking diameter, use CFD to simulate and analyze the G0-G3airway gas flow.Simulating the airway hyper responsiveness (AHR) of asthma, according to therespiratory airways flow field characteristics, analyze the mechanical factors how to work in asthma. The results of numerical simulation show that using the above methodto establish theory finite element model of respiratory can be obtained the flow fielddistribution of the airway gas in the entire respiratory tract contraction process, andwhen the blocking range1/3in airway and inlet gas flow velocity reach a certain value,airway contraction area appear eddy, the shear stress increase. Although the paperestablishes biomechanical model for human respiratory airway, but its technologyplatform and simulation method is also applicable to other research on thebiomechanical behavior of fluid motion, which has a certain value.