Study On Unsteady Numerical Simulation Of Multiphase Pollutants In Aircraft Cabin

The cabin of the aircraft is densely populated,the geometry is complex,and it is a semi-enclosed space.The unreasonable ventilation design in the cockpit will cause pollutants to propagate and spread inside the cockpit,making the cabin The health of internal passengers is seriously threatened by pollution problems such as respiratory diseases.Therefore,it is necessary to provide theoretical support for improving the air quality in the cabin and reducing the impact of pollutants by studying the characteristics of the flow field in the cabin,the mechanism of pollutant propagation and its influencing factors.A model of the B737-200 cockpit is established,through numerical simulation and simulation cabin experiments,the characteristics of the flow field and multiphase pollution in the cabin of the aircraft under mixed air supply,side air supply,and ceiling air supply are studied.The propagation trajectories of particles are studied,and the influence of flow field characteristics on the propagation of pollutants is analyzed.The time-averaged flow field is analyzed first,and then the airflow pulsation in the transient flow field is studied.Then focus on the collision area of the airflow in the central cabin aisle,and perform modal analysis on the transient flow field by proper orthogonal decomposition.The motion trajectories of multiphase pollutant particles in the flow field are simulated,and the path trajectories are classified,and the pros and cons of the three operating conditions are evaluated from a statistical perspective.By analyzing the characteristics of the airflow in the cabin of the aircraft,the macroscopic airflow movement trend and the small-scale airflow pulsation caused by the unsteady state characteristics under three operating conditions are clarified.The propagation trajectories of pollutant particles in the cabin was obtained,and the reasons for the trajectory of pollutant particles were explained in combination with the characteristics of the airflow field.At the same time,the performance of the pollutant discharge in each operating condition was evaluated in the form of probability.The results show that the airflow field structure in the cabin is quite different under different air supply conditions,and this difference has adirect impact on the spread of pollutants,which determines the difference in the pollutant propagation law.