民用飞机适航用临界冰形的确定及验证

对民用飞机结冰适航取证用临界冰形确定及验证进行研究。在民用飞机结冰适航取证过程中,首先需要确定临界冰形,为结冰后的性能和操稳评估提供冰形输入。首先确定临界冰形的判断标准,制定临界冰形确定的工作思路;然后采用SADRICE结冰数值软件开展结冰冰形参数的敏感性分析,获取临界结冰条件;最后通过冰风洞试验对参数敏感性结论进行验证。结果表明数值模拟参数敏感性分析结论与冰风洞试验结果一致,数值模拟所得临界冰形上冰角与冰风洞试验一致,下冰角存在一定差异,但不影响冰形临界性判断结论。参数敏感性分析所得临界结冰条件以及冰风洞试验所得临界冰形正确,可作为结冰适航取证临界结冰条件及临界冰形。临界冰形确定思路、方法可为其他民用飞机结冰适航取证提供参考。

Determination and verification of critical ice shape for the certification of civil aircraft

Ice accretion of civil aircraft has been a major concern to flight safety.The civil air-craft must show compliance with the airworthness icing regulation to make sure that the aircraft can fly safely under the icing condition.The critical ice shape is the most important input for the evaluation of performance/stability and control under the icing condition,and therefore it must be determined at the very begining of ice certification.Firstly,the standard of the critical ice shape is set up,and the procedure of the critical ice shape determination is proposed.Then,the sensi-tivity of the icing conditions has been analysed by SADRICE code,and the critical icing condition is obtained.Icing wind tunnel tests have been conducted in Italian Aerospace Research Center to verify the critical icing condition.The test results show great agreement with numerical simula-tion results.It is found that MVD= 20μm,RAT= 0℃ is the most critical icing condition for the aircraft under research.Test and numerical resuts of the angle and height of the ice shape upper horn are the same,testifying the correctness of the sensitive analysis and the relevant critical ic-ing condition.The critical ice shape can be used in aircraft icing certification.This is of value to other aircrafts icing certifications.