Numerical Simulation Of Reasonable Row Number For An Aircraft Cabin And The Contaminant Transportation

With the increasingly popularity of air travel for the public travelling, it is crucialto study the airflow in the aircraft cabin for creating a thermal comfortable andhealthy environment. The air flow field inside aircraft cabin is complex andinfluenced by various fluid mechanical phenomena such as complex boundaryconditions, buoyancy forces and thermal plumes interactions and supplied air jets.Many studies relating to airflow inside aircraft cabin have been carried out withexperimental measurement and numerical simulation. While among so many studies,there is no research showing a reasonable row number which can obtain relativecorrect results that can be used to be on behalf of the flow characteristics of the wholecabin. Due to the difference with each other in the existing studies such as the variouscabin models and different boundary conditions, it is impossible to carry out acomparative analysis of the existing research results. As the complex geometry andairflow boundary conditions have large impact on the airflow in the aircraft cabin, it isessential to explore the airflow inside the aircraft cabin with the same geometricmodel and the same air boundary conditions to obtain a reasonable row number.During the last few years CFD technology has progressed and made it an easyand fast alternative to analyze the air distribution and contaminant transmission incommercial aircraft cabins. To explore the airflow inside an airliner cabin, a fulllength cabin is needed theoretically, but a CFD simulation to study contaminanttransport for a few minutes in a full length airliner cabin can take a few weeks ofcomputing time even if a computer cluster is used. It is difficult to make a CFDsimulation for full size aircraft cabins due to the limit of computer source and timecost, researchers have to choose several rows cabin mockup to get CFD simulationresult. This investigation explored the reasonable row number in a section of asingle-aisle aircraft cabin with a validated Computational Dynamic Fluids (CFD)program. The RNG k-model for the turbulent flow was used to simulate a steady airflow in the cabin environment during cruise flight. The simulation of reasonable rownumber cases include empty cabin and fully-occupied cabin and the row numberincluded one row, three rows, five rows, seven rows and nine rows cabin mockup. Itfound that as for the empty cabin, due to the influence of complex geometry boundary,five rows cabin is enough for simple numerical simulation and seven rows cabin can get good results. As the thermal plume from manikin had larger impact on airflowdistribution inside the aircraft cabin compared to geometry boundary, three-row cabinis enough to the numerical simulation of fully-occupied cabin. With the obtainedreasonable full-occupied row number, this investigation further compared the airdistribution and airborne pollutants transportations between half-occupied cabin andfull-occupied cabin. It found that differ from full-occupied condition, air distributionin the half-occupied aircraft cabin appeared asymmetrical. Airflow deviated from aisleto the side with more people. The sphere of influence of contaminant under halfoccupied condition was larger than that of fully-occupied condition. Moreover,through the comparison of ventilation index, it showed that due to the lateral spread ofthe airflow, the pollutant cross infection of half-occupied condition was much moreserious than that of fully-occupied condition.