Research On Combustion Characteristics And Smoke Spread Law Of Civil Aircraft Cabin Fire

In recent years,the global economy and trade are becoming more and more integrated,and the cross-regional business cooperation and personnel exchange have greatly promoted the development of civil aviation transportation.With the rapid increase in the global demand for civil aircraft,domestic and foreign scholars gradually pay attention to the related research on civil aircraft flight safety.According to statistics,fire is one of the major threats to civil aircraft flight safety,in the safety accidents caused by civil aircraft,the proportion of fire accidents is relatively high.Once a fire breaks out in the passenger cabin,the fire may spread quickly,and high temperature and poisonous smoke will seriously threaten the safety of people,it is extremely easy to cause huge economic losses and bad social effects,so it is necessary to study the combustion characteristics and smoke spread law of civil aircraft cabin fire,it can provide a theoretical reference and scientific basis for formulating effective fire prevention measures and evacuation strategies for civil aircraft,and is of great value for improving the system safety of civil aircraft flight.In this study,the large-scale cone calorimeter fire test and numerical simulation are combined to study the Airbus A320,which has a large memory and high utilization rate in China,the combustion characteristics of cabin fire and the law of smoke spread were studied.First of all,the fire burning test based on cone calorimeter was carried out,under different ignition power(20kw,100kw)and different fan flow rate(1.8 m~3/s,2.5m~3/s),the main combustibles in the Airbus A320 cabin,such as the aviation seat,the aviation carpet and the baggage carried by passengers,were tested in fire combustion,and the combustion characteristics such as the heat release rate,the mass loss rate,the ignition time and the total amount of heat release were analyzed,then,according to the data of the full-scale fire test of the main fuel in the passenger cabin,the power of the fire source in the passenger cabin of civil aircraft is calculated by using the mass loss rate calculation and the method of the stable fire source model,FDS numerical calculation model is established to simulate 6 different fire scenarios,analyze the law of cabin fire and smoke spread,and put forward the measures and suggestions for preventing and controlling cabin fire and evacuating personnel,the specific research shows that:(1)Through the fire burning test of the main combustible materials such as seats,luggage,carpets,etc.in the cabin,the results show that the ignition time is 200s,the heat release rate is 1362kw/m~2,the total heat release is 450MJ/m~2 and the mass loss rate is 4.28 g/s when the ignition power is 100kw and the fan flow rate is 2.5 m~3/s The ignition time is 25s,the heat release rate is 260kw/m~2,the mass loss rate is 2.5 g/s,the ignition time is 250s,the mass loss rate is 0.63 g/s.(2)Through the comparison and analysis of full-scale fire test data under different ignition power(20kw,100kw)and different fan flux(1.8 m/s,2.5 m/s),it is concluded that when the ignition power is the same as 20kw,when the fan flow rate is 2.5 m/s,the time for the air seat and passenger baggage to reach the peak of heat release rate is obviously shorter than the time for the fan flow rate is 1.8 m/s,which indicates that the bigger the fan flow rate is,the faster the fire development of the air seat and passenger baggage is.When the flow rate of the fan is 1.8 m/s,the mass loss rate of the air seat and passenger luggage is obviously larger when the ignition power is 100kw than when the ignition power is 20kw,which shows that the higher the ignition power is,the better the combustion is.According to the data obtained from the fire test,the mass loss rate calculation method and the stable fire source model analysis method are used for calculation and analysis,considering the particularity of the actual combustion situation in the passenger cabin,the final conservative estimate of the civil aircraft cabin fire power is 50.95 MW.(3)Based on the fire test,the FDS numerical simulation model is constructed,and the combustion parameters of various materials tested in the test are introduced,so that the numerical simulation results are closer to the real scene,the temperature and smoke concentration of the cabin were obtained under six working conditions,including the position of the fire source and the different state of the emergency cabin door,and the analysis showed that the cabin was affected by the oxygen concentration in the confined space when the emergency cabin door was closed,the fire in the cabin first increased and then decreased,and the smoke concentration per unit increased first and then decreased slowly with the fire,the available safe evacuation time is 149s when the emergency cabin door is closed and 147s when it is open,and 153s and 160s when the fire source is in the middle of the cabin door When the fire source is located at the rear of the cabin,the available evacuation time is 173s when the emergency cabin door is open and 155s when the emergency cabin door is closed,the continuous passage of fresh oxygen into the cabin leads to the high oxygen concentration in the cabin,which makes the cabin burn more fully.Therefore,when formulating the active and passive fire prevention measures for the passenger cabin of civil aircraft,the corresponding active smoke exhaust devices can be designed,in order to achieve smoke exhaust and prevent the introduction of fresh oxygen purposes.The conclusions of this study can provide theoretical reference for the design of fire prevention technology,the evacuation strategy and the judgment of evacuation safety time in civil aircraft cabin The conclusions of this study can provide theoretical reference for the design of fire prevention technology,the evacuation strategy and the judgment of evacuation safety time in civil aircraft cabin.