考虑氧逸出的多舱燃油箱惰化理论研究

在考虑到氧逸出条件下,用数值积分的方法建立了多舱油箱燃油冲洗的数学模型。以波音747中心翼油箱为研究对象,对模型进行求解,得到了各舱氧浓度分布随着通风换气次数的变化规律。与已有文献的实验结果和计算结果对比发现,该模型具有较高的计算精度。用该模型研究了不同载油率和不同的通风形式下各舱的惰化效果。结果显示,随着载油率的下降,各舱达到给定氧浓度所需的换气次数增加。改变通风形式,对各舱惰化效果影响显著。提出在对多舱油箱进行冲洗惰化设计时,应将"最不利舱"的因素考虑在内。该研究可为多舱油箱惰化工程设计提供相应的支持,为通风系统的优化提供理论依据。

Theoretical Study on Inerting Process for Multi-Bay Fuel Tank Based on Oxygen Evolution

Considering the evolution of the dissolved oxygen from fuel,the washing inerting mathematical model of ullage for multi-bay fuel tank is set up based on the infinitesimal method.Adopting Boeing 747 central wing tank as the object,the model is solved and the varying regular patterns of oxygen concentration of each bay related to the inerting time are obtained.By comparing the calculating results with the published data,the model has higher accuracy.The influences of different fuel load and ventilation mode on inerting effect of all bays are investigated and compared.When the fuel load decreases,the volumetric tank exchange needed for a given oxygen concentration of each bay increases.Changing the ways of ventilation has a significant influence on inerting effect of each bay.The multi-bay fuel tank inerting system takes into account a concept of ″worst bay″,first proposed in this paper.This study can support the engineering design of the fuel tank inert and supply a theoretical base for the optimization of pipe arrangement.