APU舱门局部结构排液分析

依据APU舱排液相关的适航条款要求，在10 min内需要通过排液结构排出超过90%的舱内积液且不增加额外着火风险。由于舱门为APU舱的主要排液结构，为满足适航要求，目前已有针对民用飞机APU舱门排液分析方法的研究工作，主要从结构总体布局的角度出发，假定全APU舱存在唯一确定排液口，讨论分析了排液口尺寸与排液速率的关系。但对于局部结构的排液能力鲜有讨论，当APU舱门采用分段密封件布局时，不当的结构外形以及不合理的尺寸设计，可能导致可燃液体从密封搭接位置泄露，从而增加意外着火的风险，因此局部结构的排液设计对于舱内液体安全有效的排放同样十分重要。基于大型客机APU舱门的排液需求，分析了舱门局部积液结构的排液能力以及相关影响因素，针对此类因素，确定其设计要点，并分别给出了对应的结构优化措施。

Drainage analysis of partial structure of APU compartment

The airworthiness clause about the drainage of APU compartment requires more than 90% of the liquid to be discharged through the structure within 10 min without additional fire risk. Because the door is the main drainage structure of APU compartment, in order to meet the airworthiness requirements, there has been research work on the drainage analysis method of civil aircraft APU door. From the perspective of the overall structure layout, assuming that there is a known and unique discharge port in the wholeAPU compartment, the relationship between the discharge port size and the discharge rate was discussed and analyzed. However, there is little discussion on the discharge capacity of the local structure. When the APU door adopts the sectional seal layout, the inappropriate structure shape and unsuitable size design may lead to the leakage of combustible liquid from the seal gap which will increase the risk of accidental fire. Therefore, the drainage design of the local structure is also very important for the safe and effective discharge of liquid in the compartment. Based on the liquid discharge requirement of APU door of civil aircraft, this paper analyzes the liquid discharge capacity of local hydrops structure of the door as well as the related influencing factors, determines the design points for such factors and gives the corresponding structural optimization measures.