今年4月中旬,世界首部完整GE9X航空發(fā)動(dòng)機(jī)開始在通用電氣航空集團(tuán)(GE Aviation)位于俄亥俄州的皮布爾斯測(cè)試運(yùn)行中心(PeeblesTesting Operation)進(jìn)行地面測(cè)試。未來,這款發(fā)動(dòng)機(jī)將登陸波音公司(Boeing)的新型777X航空客機(jī)。通用航空公司GE90/GE9X項(xiàng)目總經(jīng)理Bill Millhaem表示,“地面測(cè)試可以創(chuàng)造大量有價(jià)值的數(shù)據(jù),涉及完整發(fā)動(dòng)機(jī)系統(tǒng)、空氣動(dòng)力學(xué)性能、機(jī)械校驗(yàn)以及航空熱力系統(tǒng)校驗(yàn)等多個(gè)方面。”
據(jù)悉,GE9X渦扇發(fā)動(dòng)機(jī)的成熟性測(cè)試始于大約5年前,目前已經(jīng)從最早的元件級(jí)測(cè)試一路進(jìn)行至最近的首次FETT測(cè)試(完整發(fā)動(dòng)機(jī)測(cè)試)。FETT測(cè)試會(huì)集中GE9X發(fā)動(dòng)機(jī)采用的各項(xiàng)技術(shù),旨在展示這些不同模塊作為一個(gè)完整推進(jìn)系統(tǒng)的運(yùn)行能力。
GE9X發(fā)動(dòng)機(jī)在設(shè)計(jì)確認(rèn)僅僅6個(gè)月后就開始了FETT測(cè)試,與大多數(shù)發(fā)動(dòng)機(jī)相比,研發(fā)流程要快得多。通用電氣表示,提早進(jìn)行FETT測(cè)試可以保證測(cè)試中的任何收獲都能完全反映在下一輪的發(fā)動(dòng)機(jī)認(rèn)證測(cè)試中。GE9X發(fā)動(dòng)機(jī)的認(rèn)證測(cè)試定于明年進(jìn)行,屆時(shí)還有將在通用航空公司的飛行測(cè)試床上進(jìn)行的飛行測(cè)試。這款發(fā)動(dòng)機(jī)的適航認(rèn)證預(yù)計(jì)將在2018年開始。
據(jù)悉,多家公司均參與了GE9X航空發(fā)動(dòng)機(jī)研發(fā)項(xiàng)目,其中包括石川島重工(IHI Corporation)、斯奈克瑪(Snecma)、賽峰集團(tuán)(Safran)旗下航空航天技術(shù)公司(Techspace Aero),以及MTU航空發(fā)動(dòng)機(jī)集團(tuán)(MTU Aero Engines AG)等。
賽峰集團(tuán)旗下另一家公司埃塞(Aircelle)憑借為波音777X供應(yīng)的鈦材料發(fā)動(dòng)機(jī)尾氣系統(tǒng),躋身波音公司的主要供應(yīng)商之一。這款尾氣系統(tǒng)將參與波音與通用電氣兩家公司的發(fā)動(dòng)機(jī)合作研發(fā)項(xiàng)目。該尾氣系統(tǒng)的尺寸很大,是同類型民用飛機(jī)中最大的。由于采用了同樣也是基于鈦材料的降噪解決方案,這款尾氣系統(tǒng)的噪聲水平明顯更低。
由于埃塞公司采用了鈦材料高溫應(yīng)用處理工藝,GE9X發(fā)動(dòng)機(jī)的尾氣系統(tǒng)不僅可以帶來更高的質(zhì)量效率,而且還具有更高的耐熱性。埃塞公司優(yōu)化了鈦材料機(jī)艙元件的設(shè)計(jì)和制造,具體是利用公司的專業(yè)技能和專利數(shù)據(jù)庫,對(duì)這種金屬材料在尾氣系統(tǒng)中的應(yīng)用進(jìn)行驗(yàn)證。埃塞公司不但專門斥資為777X項(xiàng)目升級(jí)了公司的生產(chǎn)資源,還與波音公司合作,以確保公司的生產(chǎn)流程完全合乎波音的生產(chǎn)要求。
目前,GE9X的訂單已經(jīng)累計(jì)到700臺(tái)。這款發(fā)動(dòng)機(jī)屬于10萬磅推力級(jí)別,前方渦扇的直徑可達(dá)134英寸,帶有一個(gè)復(fù)合材料渦扇套,以及16片用第四代碳纖維復(fù)合材料制成的渦扇葉。此外,這款發(fā)動(dòng)機(jī)還采用了壓縮比高達(dá)27:1的下一代11段高壓壓縮機(jī)、第三代TAPS III高效低排燃燒室,并在燃燒室和渦輪機(jī)中應(yīng)用了CMC材料(即陶瓷基復(fù)合材料)。
作者:Jean L. Broge
來源:SAE《航空工程》雜志
翻譯:SAE 上海辦公室
Ground testing begins on the GE9X
In mid April, ground testing began on the first full GE9X development engine at GE Aviation’s Peebles Testing Operation in Ohio. The GE9X engine will power Boeing’s new 777X aircraft. According to Bill Millhaem, General Manager of the GE90/GE9X engine programs at GE Aviation, “The ground testing will generate data on the full engine system and aerodynamic performance, mechanical verification, and aero thermal system validation.”
Maturation testing of the GE9X turbofan engine began about five years ago and has progressed from component-level all the way to the recent first full engine to test (FETT). FETT brings all the GE9X technologies together to demonstrate their operability as a complete propulsion system.
The GE9X FETT began just six months after the engine's design was finalized, which is much earlier in the development process compared to most other engine programs. GE says this timing assures that everything learned from FETT will be captured in the certification engines. Next year will see the GE9X program starting certification testing and flight testing on GE Aviation’s flying test bed. Engine certification is anticipated in 2018.
IHI Corporation, Snecma and Techspace Aero (Safran), and MTU Aero Engines AG are just a few of the participants in the GE9X engine program
Another Safran company, Aircelle, is supplying titanium engine exhaust systems for the 777X, marking its first major role as a supplier to Boeing. The exhaust system is being used as part of the overall engine development program in partnership with Boeing and GE. These exhaust systems are among the largest of their type ever produced for civil aircraft, and include acoustical treatment areas, also of titanium, for a reduced noise level signature.
The exhaust systems on the two GE9X engines offer both mass efficiencies and increased resistance to heat primarily as a result of Aircelle's processes for titanium high-temperature applications. Aircelle has optimized the design and manufacturing of titanium nacelle components, applying its expertise and proprietary database in defining and validating the metal's performance for exhaust systems. The company has invested in new and upgraded production resources for the 777X program, while also working with Boeing in ensuring routines and procedures are fully compliant with its production requirements.
With almost 700 GE9X engines on order, the GE9X engine will be in the 100,000-lb thrust class and will have a large front fan 134-in in diameter with a composite fan case and 16 fourth-generation carbon fiber composite fan blades. Other key features include a next-generation 27:1 pressure-ratio 11-stage high-pressure compressor; a third-generation TAPS III combustor for high efficiency and low emissions; and CMC material in the combustor and turbine.
Author: Jean L. Broge
Source: SAE Aerospace Engineering Magazine