Research On Smoke Diffusion Regularity In Aircraft Cabin And Compliance Verification Technology

The aircraft cabin environment smoke accident can threaten the flight safety seriously. According to the incomplete statistics, the cabin smoke accident happens one time in every 5,000 flights. As a result, more attention is paid on the airworthiness verification of the cabin smoke to ensure the aircraft safety. However, lacking the knowledge of the diffusion law of cabin smoke sometimes makes the verification experiment of the cabin smoke dangerous and expensive.With the rapid progress of computer technology, computational fluid dynamics(CFD) is widely used. In addition, utilizing computer modeling and simulation before the verification experiment can significantly improve the operability and feasibility of the experiment.This paper analyzes the flow regularity of smoke in the aircraft cabin and the influence of ventilation on cabin smoke diffusion by Fluent, which could prove analysis/calculation to be one of airworthiness compliance verification methods and decrease the costs of ground test and flight test which is able to reduce cost and increase efficiency.First of all, this paper primarily employs the method of numerical simulation to emulate the cabin smoke diffusion by utilizing demonstrated CFD model, thereby obtaining the flow regularity and tendency of the smoke in the cabin by time.Passengers who sit near the fire are at higher risk when the fire is located in the middle of the cabin. Besides, affected by the ceiling jet and horizontal inlet air, the smoke accumulate sat the top of the compartment and the concentration and temperature of the smoke at the top of the aisle is higher than that in the seat area, as well as the concentration of the smoke is large at the junction of longitudinal sidewall face and ceiling.The next, based on the obtained regularity, and according to comparing the concentration and temperature of the smoke at each key position, the smoke diffusion on three different conditions of ventilation can be researched. Under the three different conditions of ventilation, the higher ventilation is, the lower will the concentration of cabin smoke be, and the concentration and temperature of the smokeat the ceiling area and passengers breathing area is exceedingly influenced by ventilation. On top of that, the smoke is precluded from spreading quickly from aisle area to passenger area by the horizontal inlet air. As a consequence, higher ventilation is conducive to smoke discharging. Finally, the smoke from outside the cabin is simulated. Under this ventilation mode, smoke concentration in passengers breathing area is low. This ventilation mode reduces the smoke threat to passengers.