Combustion criterion analyzing method of dry chamber near oil tank under impact of metal chips

Abstract

The invention provides a combustion criterion analyzing method of a dry chamber near an oil tank under impact of metal chips. A relation diagram of changes of an airplane combustion envelope along with an airplane flight profile is calculated through a formula according to an airplane flight profile diagram and a formula of the fuel oil flash point temperature. A combustion triangular diagram is drawn by analyzing the influence relation between the temperature and a fuel oil combustion limit, the pressure and the fuel oil combustion limit, the height and the fuel oil combustion limit and the fuel oil components and the fuel oil combustion limit respectively and calculating the limit oxygen concentration of the fuel oil. Combustion criteria can judge conditions of combustion of the dry chamber near the oil tank under different flight heights accurately, expression forms of a fuel combustion envelope and a combustion triangular form are simple and intuitionistic so that the method is beneficial for reduction of probability of occurrence of airplane combustion explosion, viability of an airplane is improved, and meanwhile the method can be applied to judgment of combustion when oil tanks of communication media such as motorbikes, automobiles and steamships are impacted by high-speed metal chips.

Description

technical field [0001] The invention relates to the field of high survivability analysis and design of an aircraft fuel system, in particular to an analysis method for the occurrence conditions of an aircraft fuel tank being hit by high-speed metal fragments to cause fire and continuous combustion in a nearby dry compartment. Background technique [0002] Aircraft dry compartment refers to the compartment or cavity located between the outer skin of the aircraft and the internal structure. The dry compartment is usually distributed with hydraulic pipelines, fuel pipelines, avionics equipment and lines, etc. The combustion or explosion caused by the impact and penetration of high-speed metal fragments in the dry compartment usually leads to secondary damage to the surrounding structures. Such as fuel tank combustion or explosion, damage to avionics equipment, damage to load-bearing structures around the dry compartment, etc. These often result in the failure of the aircraft's...

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Problems solved by technology

[0008] The present invention first analyzes the fuel tank penetration model under the impact condition of high-speed metal fragments, and solves the penetration problem of the fuel tank wall through the JTCG / ME penetration equation; analyzes the quality of the fuel oil that leaks into the nearby dry compartment through the perforation of the fuel tank wall through the fuel oil leakage mass flow rate ; Solve the problem of oil and gas concentration in the dry tank through the evaporation flux of fuel

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