基于LTO循环航空发动机排气污染物NOx排放适航审定计算方法

 航空器要获得商业营运许可,必须取得适航证,适航要求是航空器安全飞行的最低法规性的保障,因此研究航空发动机排放适航审定方式是非常有必要的。为解决中国民用航空发动机测试数据处理方式中的技术难点,使飞机发动机排气污染物符合适航审定标准,参考国际民航组织(ICAO)颁布的“飞机发动机排放”条例的规定,设计了民用航空发动机排气污染物测量系统。测量系统的精度按标准规定用燃气分析测出的油气比与发动机实测油气比进行比较小于10%—15%的属于合格。本研究的测量值与发动机所测的油气比的误差小于7%,证明测量系统和测量技术是切实可行的。基于ICAO标准的起飞着陆(LTO)循环概念,采用ICAO计算方法得出航空发动机NO_x的排放指数。根据中国民航规章34部(China Civil Aviation Regulations,CCAR—34),验证得出航空发动机JT3D—7的NO_x排放符合现行的适航标准。根据ICAO计算方式,利用MFC开发了NO_x适航审定系统,可快速算出发动机NO_x排放指数,并可对发动机进行NO_x排放适航审定。

Airworthiness Certification Calculation Method of Gas Turbine Engine NOx Emissions Based on LTO Cycle

The airworthiness certification is necessary before the aircraft enters into the commercial operation. The requirement of the airworthiness is the basic regulation guarantee for the safe flight of aircraft; therefore it is necessary to study the airworthiness certification method for gas turbine engine emissions. In order to solve the technical difficulty of the methods involving gas turbine engine emission test data and meet the requirement for engine emissions airworthiness certification standard, an emission measuring system is designed with reference to Aircraft Engine Emissions promulgated by the convention of ICAO. The accuracy of this system is no more than 7%, it is much better than 10%—15% based on the procedure for the analysis and evaluation of gaseous emissions from aircraft engines requirement, so that the sampling and measurement system is proved feasible. Calculation of NO_x emission index from aircraft is developed by using ICAO method based on the ICAO standard involving Landing and Take-Off (LTO) cycle. JT3D-7 NO_x emission is compatible with the existing regulatory standards according to CCAR-34. According to the method of ICAO, a system for the airworthiness certification of gas turbine engine emissions is developed by MFC and NO_x emission index of the engine could be quickly computed.