過去幾十年中，“空中自動(dòng)駕駛汽車”和“空中出租車”一直是科幻電影的常用元素，如今，這一切可能即將成為現(xiàn)實(shí)。Embraer現(xiàn)已宣布計(jì)劃開發(fā)一種極具未來風(fēng)格的小型商用飛行器。事實(shí)上，有意挺進(jìn)空中移動(dòng)出行市場(chǎng)的公司并不只有Embraer。多家公司均已開展空中飛行器項(xiàng)目，并且都聲稱自己的產(chǎn)品將在未來幾年內(nèi)顛覆人們的空中移動(dòng)出行方式。
Embraer從設(shè)計(jì)開發(fā)渦輪螺旋槳運(yùn)輸機(jī)系列開始，發(fā)展至小型噴氣式客機(jī)和公務(wù)機(jī)領(lǐng)域，并最終進(jìn)入 140 座的雙發(fā)噴氣機(jī)市場(chǎng)，目前全球總銷量達(dá) 8000 多臺(tái)。Embraer的發(fā)展對(duì)巴西的飛機(jī)設(shè)計(jì)和制造能力的躍升做出了巨大貢獻(xiàn)。
這些產(chǎn)品線取得了巨大的成功，并同時(shí)確立了Embraer作為一家全球領(lǐng)先航空航天企業(yè)的地位。然而，迄今為止，Embraer的產(chǎn)品仍屬于傳統(tǒng)設(shè)計(jì)，也就是選擇全球頂級(jí)供應(yīng)商的最佳新功能進(jìn)行整合，不斷將更高性能的節(jié)油引擎、集成式線控航空電子系統(tǒng)、玻璃駕駛艙融入自己的新設(shè)計(jì)中，并同時(shí)越來越多地采用復(fù)合材料零部件。
不過，這種情況即將成為歷史。目前，Embraer旗下分公司 Embraer X （位于佛羅里達(dá)州墨爾本）已經(jīng)宣布將推出一款有潛力改變行業(yè)面貌的全新電動(dòng)垂直起降（eVTOL）概念機(jī)，昂首挺進(jìn)顛覆性的空中移動(dòng)出行市場(chǎng)。Embraer X 旨在研發(fā)高度創(chuàng)新、挑戰(zhàn)極限、甚至有可能改變行業(yè)規(guī)則的航空飛行器，并在不久的將來推出真正可以進(jìn)入市場(chǎng)的新產(chǎn)品。
目前，Embraer在美國(guó)硅谷和波士頓都有研發(fā)團(tuán)隊(duì)，專門負(fù)責(zé)與其他創(chuàng)新團(tuán)隊(duì)的溝通和合作?，F(xiàn)階段，Embraer X 的首要任務(wù)是與其他企業(yè)一起探討以下圖景的實(shí)現(xiàn)可能性——基于目前快速增長(zhǎng)的VTOL無人機(jī)和電力推進(jìn)技術(shù)，研發(fā)出一種與現(xiàn)有飛機(jī)截然不同的飛行器，并將其發(fā)展成為一種革命性但很實(shí)用的出行方案，以滿足不斷增長(zhǎng)的、對(duì)更直接、更私人的高端城市交通方式的需求。
今年 5 月，Embraer X 公司在洛杉磯舉辦 2018 年 Uber Elevate 活動(dòng)中發(fā)布了旗下具有革命意義的全新移動(dòng)出行概念機(jī)的設(shè)計(jì)理念。
當(dāng)時(shí)，Embraer 公司總裁兼 CEO Paulo Cesar de Souza e Silva 表示，“我們堅(jiān)持不懈地追求持續(xù)增長(zhǎng)，通過創(chuàng)立 Embraer X 公司，我們將推動(dòng)顛覆性創(chuàng)新的到來，并加速拓展具有指數(shù)性增長(zhǎng)潛力的新業(yè)務(wù)。城市移動(dòng)出行轉(zhuǎn)型條件已經(jīng)成熟，而我們將盡全力在這個(gè)關(guān)鍵市場(chǎng)發(fā)揮關(guān)鍵作用。”
eVTOL 的最初設(shè)計(jì)將全部從安全性、乘客體驗(yàn)、價(jià)格成本、低噪聲、小排放等最根本的關(guān)鍵驅(qū)動(dòng)因素出發(fā)。
De Souza e Silva補(bǔ)充道，“我們正在開發(fā)一種‘按需提供’的城市空中移動(dòng)出行解決方案，為數(shù)百萬城市人口提升出行質(zhì)量。通過與相關(guān)方面的共同努力，我們將努力加快實(shí)現(xiàn)這個(gè)全新的生態(tài)系統(tǒng)。”
如果我們與優(yōu)步提出的Elevate 生態(tài)系統(tǒng)比較來看， eVTOL 項(xiàng)目反映了 Embraer X 公司搶占領(lǐng)先地位、迎接挑戰(zhàn)與困難，并持續(xù)保持競(jìng)爭(zhēng)力的決心，但同時(shí)，這也的確將為這家巴西飛機(jī)制造商帶來嚴(yán)峻的技術(shù)挑戰(zhàn)，研發(fā)難度遠(yuǎn)超現(xiàn)有飛機(jī)設(shè)計(jì)的水平。
首先，電力推進(jìn)系統(tǒng)具有清潔、安靜的特點(diǎn)，因此毫無疑問地成為了新飛行器的首選。從現(xiàn)有的配電設(shè)施和新材料的發(fā)展趨勢(shì)來看，電力推進(jìn)系統(tǒng)將成為行業(yè)最有可能采用的動(dòng)力技術(shù)路線，而未來幾年內(nèi)系統(tǒng)本身的發(fā)展也會(huì)進(jìn)一步鞏固其地位。當(dāng)今無人機(jī)采用的多傾斜螺旋槳或旋翼設(shè)計(jì)展現(xiàn)出了出色的控制水平和穩(wěn)定性，有望成為新飛行器的標(biāo)準(zhǔn)架構(gòu)。
然而，盡管這種無人機(jī)架構(gòu)很容易拓展成為載客量相對(duì)較少的飛行器，但點(diǎn)到點(diǎn)飛行的續(xù)航時(shí)間依然難以保證。
盡管具有低噪聲和小排放等優(yōu)勢(shì)，但幾乎所有目前提出的VTOL飛行器設(shè)計(jì)的續(xù)航里程都大大低于同級(jí)別的傳統(tǒng)輕型直升機(jī)。由于充電期間飛行器是無法產(chǎn)生收益的，因此停工時(shí)間是目前飛行器面臨的一個(gè)重要問題。未來的空中出租制造商已經(jīng)在研究多種解決方案，其中一種就是將乘客艙，或“負(fù)荷艙”轉(zhuǎn)移至已經(jīng)充好電的飛行器中。隨著技術(shù)的進(jìn)步電池重量將穩(wěn)步下降，但對(duì)一輛輕型空中汽車而言，可能依然是一個(gè)較大的負(fù)擔(dān)。
無論如何，只有經(jīng)過計(jì)算機(jī)仿真、平臺(tái)驗(yàn)證測(cè)試及最終的實(shí)際飛行評(píng)估后，飛機(jī)制造商才能真正了解這種日常 eVTOL飛行器的實(shí)現(xiàn)可能性，讓我們拭目以待吧。
Autonomous flying cars and air-taxis have been the subject of science fiction movies for decades, but Brazilian aerospace manufacturer Embraer has now announced plans to develop a practical – if futuristic – small commercial air vehicle. However, Embraer is far from alone as a new generation of disruptive aerial projects emerge from new and established companies, all claiming they will change how we use air transport in the coming years.
There has been a huge leap in aircraft design and manufacturing capability in Brazil as Embraer gradually evolved families of regional turboprop transports and then expanded into small jet feeder- liners and business jets; until finally entering into the 140-seat twin jet market, with over 8,000 global sales in total.
These product lines have been highly successful and confirmed Embraer as a global aerospace player, but to date they have all been conventional in concept, taking the best new features from world-class suppliers, incorporating fuel-efficient engines, integrated avionics systems with fly-by-wire controls and glass cockpits, and increasing use of composite components.
But now the company’s new offshoot, Embraer X, based in Melbourne, Florida, has moved into the front-line of disruptive innovation with its announcement of a new electric-powered Vertical Take-Off and Landing (eVTOL) aircraft concept. This company has been created to develop highly innovative, potentially game-changing, aerospace projects taking technologies to the limit, and leading to new products in the not-too-distant future.
There are Embraer innovation teams in Silicon Valley, California, as well as in Boston, who are integrating and collaborating with other innovation communities. At this stage the company priority is to join with other enterprises to examine the realistic prospects for introducing a radically different air vehicle that takes today’s rapidly expanding VTOL drone and electric technology and up-scales it to provide a revolutionary, yet practical, solution for meeting the needs of growing, more sophisticated, communities who will need direct, and more personal, transport – especially in city environments.
Embraer X used the occasion of the Uber Elevate 2018 event in Los Angeles, in May, to unveil its outline aircraft design.
“We are relentless in our quest for constant growth and through Embraer X we will drive disruptive innovation and accelerate the creation of new businesses with the potential for exponential growth. Urban mobility is ripe for transformation and we are committed to having a major role in this key market,” said company president and CEO, Paulo Cesar de Souza e Silva.
The eVTOL initial design is built around what are described as key-drivers – safety, passenger experience, affordability and very low noise and emissions footprint for the community.
“We are developing solutions to bring on-demand air transportation to urban areas to improve quality of life for millions of people. Our collaboration with key stakeholders will accelerate the arrival of this new eco-system,” added de Souza e Silva.
Seen in the context of Uber’s Elevate ecosystem, the new Embraer X initiative demonstrates that the Brazilian-owned company intends to keeping ahead of the current immature demand curve, to maintain a competitive position when all the many associated challenges have been identified and overcome. Those challenges do represent some steep technological mountains yet to climb as they extend well beyond the development of air vehicles, which already pose difficult design issues.
To start, the choice of electric propulsion is an obvious decision, as it is clean and quiet. Power distribution and new materials make it the most predictable course for the industry and electric propulsion technologies will firm up in the coming years. Multiple tilt propellers or rotors have made the aircraft architecture seen in today’s drones an acceptable standard for further development, as they allow for good control and stability.
However, even though they are easily adapted to larger air platforms with the relatively light, urban use payloads, there are still shortcomings when it comes to point-to-point flight time endurance.
Almost all the projected VTOL designs that have been announced to date suffer from very short range compared to an equivalent conventional light helicopter, even if they are much more acceptable in terms of noise and emissions pollution. Down-time for battery charging is an important issue for electric aircraft, as revenues aren’t earned during charging. That said, the idea of detachable passenger, or payload, pods that can be plugged into ready-charged propulsion units is one direction that is being investigated by would-be manufacturers of new air-taxi aircraft. Battery weight is steadily reducing as technology progresses, but it can represent a disproportionate payload penalty on a very light air vehicle.
When development aircraft designs have been refined on the computer screens and test rigs, and take to the air for evaluation, it will then be possible to see for the first time how realistic day-to-day electric VTOL air-taxi operations might be.
Author: Richard Gardner
Source: SAE Aerospace Engineering Magazine
Embraer X公司最新推出的 eVTOL 城市移動(dòng)概念機(jī)采用了一種清潔安靜的電動(dòng)推進(jìn)系統(tǒng)，由多個(gè)螺旋槳和旋翼產(chǎn)生動(dòng)力。目前，這款最新概念飛機(jī)已在今年 5 月舉辦的 2018 年 Uber Elevate 展會(huì)上亮相（圖片來源：巴西航空工業(yè)公司）。