作　　者： (熊磊）; (刘洋）; (毛俊）;

机构地区： 上海飞机设计研究院总体气动部,上海201210

出　　处： 《空气动力学学报》 2017年第3期399-403,共5页

摘　　要： 后缘襟翼气动载荷计算是大型运输类飞机增升装置设计工作中的关键步骤之一。在新型民用运输机的研制与适航取证工作中,发现现有的襟翼载荷计算方法在某些特殊工况下并非足够保守。某型支线客机襟翼测压试飞中测得其巡航构型下襟翼气动载荷相对计算值有较为明显的增加。在分析对比了试飞与风洞试验的压力分布数据,并借助CFD工具进行定性分析后,最终证明气动载荷的增加主要由襟翼舱的密封失效所造成。以往载荷计算时,襟翼舱内部的襟翼表面压力通常赋值为0,这在襟翼舱保持密封时是可靠的;但在实际飞行中,襟翼舱处襟翼与机翼主翼面后缘之间的密封装置通常会由于制造或受载变形等原因失效,此外该位置附近的扰流板也会在飞行时浮动或偏转,这些都会导致襟翼舱内部气压降低到当地外界的静压值,使得巡航构型襟翼压力分布在头部有一个较为明显的平台式增加。另一型单通道干线客机通过低速风洞测压试验发现在小襟翼偏度构型时襟翼的法向气动力系数有明显增加,采用该试验结果作为输入,计算得到的考虑扰流板偏转影响的小襟翼偏度构型襟翼气动载荷,甚至超过了扰流板未偏转时所有增升构型下的襟翼最严重载荷。通过对压力分布数据及CFD计算得到的二维流场的分析,证明扰流板偏转造成襟翼载荷增加的主要原因是前者对后者的上洗效应。扰流板的偏转将增加其下游襟翼处的当地迎角,使得后者在小偏度时就接近其在大偏度时的法向力系数,之后由于小襟翼偏度构型时更大的襟翼设计速度与对应速压最终造成了载荷增加。针对上述两个问题提出了符合客观流动规律的方法进行补充和修正:在计算巡航构型襟翼载荷时,可在原有测压试验得到襟翼压力分布的基础上补充平顶型前缘分布作为载荷计算输入;而在计算小襟翼偏度增 Flight load calculation has great importance to flap design of transport aircraft. Having been used for decades, traditional method is not sufficient for further design and type certification. According to the results of flight test （FT） and wind tunnel test （WT）, it has been discovered that the design load of flap is not conservative in cruise and spoiler deflection configuration. For both situations, flap load is distinctly larger than traditional result, which will cause redesign works and certification issues. By analyzing test data, and using CFD tools, key reasons to both problems have finally been found. For cruise configuration, pressure coefficient of flap cabin was often set to zero approximately in previous design, however, in real conditions, the airproof measure between flap and main wing trailing edge often fails in spite of elaborately design and manufacture; moreover, the spoilers installed before the flap may drift and deflect slightly during the flight. These can cause the flap cabin pressure coefficient less than zero and lead to a flight load increment. As to the other problem, the spoiler deflection in high-lift configuration can result in an upwash to the flap. As a result, the flap load, especially for small flap deflection configuration, increases significantly, which may be even greater than maximum flap load with non-deflection spoiler. Improved methods, which have been proved in the latest airliner design program, are given in this paper to correct the traditional flight load calculation. The key point of new methods is to simulate the pressure distribution in flap cabin more accurately for the first problem, and estimate flap load increment caused by spoiler deflection based on maximum normal force of different flap deflections for the other problem. The results, based on new methods, comply with physical rules and real flight conditions more relevantly.

关 键 词： 大型运输机 后缘襟翼 气动载荷 飞行试验 风洞试验 数值模拟