Technical contributors：Mark Hughes and Giorgio Piola

技術(shù)顧問：馬克·休斯和喬治·皮奧拉

TECH TUESDAY: Why did Mercedes fall down the order in Abu Dhabi after taking a 1-2 in Sao Paulo?

「技術(shù)周二」為什么梅賽德斯在圣保羅以1-2落后于阿布扎比？

Mark Hughes looks at Mercedes’ performance drop-off from Sao Paulo – where George Russell took their first and only win of the season – to Abu Dhabi, where Russell came home fifth and Hamilton did not finish. Giorgio Piola provides technical illustrations.

Mercedes’ recent return to form was brought up short in the final race of the season at Abu Dhabi. Just seven days after their one-two result in?Brazil, they were definitely only the third-fastest team around the Yas Marina circuit.

Following their significant floor and wing upgrade in Austin, together with a revised wing and some significant weight saving, there was a step change in the W13’s competitiveness. But that was at tracks – Austin, Mexico City and Sao Paulo – which do not unduly punish a higher level of drag.

In Abu Dhabi, the long flat-out sections of Sector 1 and the chicane-punctuated flat-out sections between Turns 5 and 9 mean that low drag is an essential part of the equation of being competitive there. It can be inferred from its performance patterns throughout the season that the W13 is a considerably draggier car than the Red Bull. At Abu Dhabi that hurt much more than at the preceding three track layouts.

馬克·休斯（Mark Hughes）觀察了梅賽德斯從圣保羅（George Russell在那里取得了本賽季的第一場也是唯一一場勝利）到阿布扎比（Abu Dhabi）的表現(xiàn)下滑，在那里拉塞爾以第五名的成績回家，漢密爾頓沒有完成比賽。Giorgio Piola提供技術(shù)插圖。

梅賽德斯最近在阿布扎比的最后一場比賽中恢復(fù)了狀態(tài)。在巴西取得1-2的成績僅僅七天后，他們絕對是亞斯碼頭賽道上跑得第三快的球隊(duì)。

在奧斯汀對地板和機(jī)翼進(jìn)行了重大升級后，再加上改進(jìn)后的機(jī)翼和一些顯著的重量減輕，W13的競爭力發(fā)生了重大變化。但這是在軌道上——奧斯汀、墨西哥城和圣保羅——這些軌道不會過度懲罰更高水平的阻力。

在阿布扎比，1號區(qū)的長平段和5號彎和9號彎之間的彎道間斷平段意味著低阻力是該地區(qū)競爭力的重要組成部分。從其整個賽季的表現(xiàn)模式可以推斷，W13是一輛比紅牛更具牽引力的賽車。在阿布扎比，這比之前的三種賽道布局造成的傷害要大得多。

This had an impact upon the team’s strategic choices, as trackside engineering chief Andrew Shovlin explained. “Looking at the FP3 timesheets we concluded we’d probably have two Red Bulls ahead of us whatever we did. We weren’t expecting to be so far behind the Ferraris – that was a bit disappointing. But the fact we knew we’d have the Red Bulls ahead meant we didn’t make any decisions based around qualifying. Everything was for the race.”

In the practice sessions Lewis Hamilton and George Russell had both tried a reduced flap angle rear wing, which reduced the straight-line speed deficit to the Red Bull and the low-winged Ferrari, but which proved slower over the lap, because of the oversteer through the tighter turns of the final sector.

Given that they expected to qualify behind Red Bull anyway and that the race was looking to be finely-poised between a one-stop and a two, Mercedes decided to run the bigger wing to help protect the tyres, even if that did make their car less raceable wheel-to-wheel because of its vulnerability at the end of the straights.

正如軌旁工程主管安德魯·肖夫林所解釋的，這對團(tuán)隊(duì)的戰(zhàn)略選擇產(chǎn)生了影響?！翱戳薋P3時間表，我們得出結(jié)論，無論我們做什么，我們很可能會有兩支紅牛隊(duì)領(lǐng)先。我們沒想到會遠(yuǎn)遠(yuǎn)落后于法拉利車隊(duì)，這有點(diǎn)令人失望。但事實(shí)上，我們知道我們會有紅牛隊(duì)領(lǐng)先，這意味著我們沒有根據(jù)排位賽做出任何決定。一切都是為了比賽。”

在練習(xí)中，劉易斯·漢密爾頓（Lewis Hamilton）和喬治·拉塞爾（George Russell）都嘗試了減小襟翼角度的后翼，這減少了紅牛和低翼法拉利的直線速度不足，但在圈內(nèi)證明速度較慢，因?yàn)樵谧詈笠欢无D(zhuǎn)彎較緊時轉(zhuǎn)向過度。

考慮到他們無論如何都希望在紅牛之后晉級，而且比賽將在一站式和兩站式之間保持良好的平衡，梅賽德斯決定使用更大的翼子板來保護(hù)輪胎，即使這確實(shí)會使他們的賽車在直道終點(diǎn)時因其脆弱性而變得不易比賽。

Another conundrum presented by the Yas Marina Circuit layout also probably hurt Mercedes more than the others. There is a degree of tyre management necessary even over a qualifying lap here. If full advantage is taken of the grip available through the long fast sweeps of Sector 1, the rear tyres will tend to be too hot for the twists of Sector 3.

Complicating things further, it is difficult to have the front tyres up to temperature for the start of the lap without overheating the rears. This presents a particular problem for Mercedes’ W13, which needs an especially aggressive out-lap to bring the front tyres up to temperature. This is a downside of the positive trait the car has not overworking the front tyres in the race.

Much of the heat management of the front tyres comes from the brake ducting arrangements inside the wheel. That of the Mercedes is very sophisticated,?as we recently discussed here. We can see the difference between the maximum brake cooling arrangement used in the thin atmosphere of Mexico and that used in Abu Dhabi.

亞斯碼頭賽道的賽道布局所帶來的另一個難題可能也比其他賽道對梅賽德斯的傷害更大。即使在排位賽中，也需要一定程度的輪胎管理。如果充分利用1區(qū)的長距離快速掃過所提供的抓地力，則后輪胎將傾向于過熱，無法進(jìn)行3區(qū)的扭轉(zhuǎn)。

更為復(fù)雜的是，在不使后輪過熱的情況下，很難讓前輪胎達(dá)到一圈開始時的溫度。這給梅賽德斯的W13帶來了一個特別的問題，它需要一個特別積極的外圈，以使前輪胎達(dá)到溫度。這是賽車在比賽中沒有過度使用前輪胎的積極特征的一個缺點(diǎn)。

前輪胎的大部分熱量管理來自車輪內(nèi)部的制動管道布置。正如我們最近在這里討論的那樣，梅賽德斯的設(shè)計非常復(fù)雜。我們可以看到在墨西哥稀薄大氣中使用的最大制動冷卻裝置與在阿布扎比使用的最大制動器冷卻裝置之間的差異。

“We don’t seem to change that [ducting] as much as some,” says Shovlin. “Generally we’re trying to keep the rubber on the cooler side as that allows it to last a bit longer and keeps the pressures from rising too high. Others are trying to put more temperature in than we are.”

The more brake cooling, the more heat is transferred into the rims and tyres. In Mexico, full priority had to be given to the brake cooling, which is extremely marginal there. Hence keeping the front tyres cool had to assume less importance there, but around Abu Dhabi the tyre cooling once more took priority, as an important part of the car’s good tyre usage in the race.

As with the wing choice, it emphasised how much Mercedes’ decisions were based upon race day performance rather than qualifying.

肖夫林說：“我們似乎沒有像某些人那樣改變這種管道?！薄耙话銇碚f，我們試圖將橡膠保持在較冷的一側(cè)，因?yàn)檫@樣可以讓橡膠保持更長的時間，并防止壓力過高。其他人則試圖比我們更高的溫度?！?/p>

制動器冷卻越多，傳遞到輪輞和輪胎的熱量就越多。在墨西哥，必須充分優(yōu)先考慮制動器冷卻，這在那里是極其邊緣的。因此，保持前輪胎的冷卻在那里不太重要，但在阿布扎比，輪胎冷卻再次成為首要任務(wù)，這是賽車在比賽中良好使用輪胎的重要組成部分。

與機(jī)翼選擇一樣，它強(qiáng)調(diào)了梅賽德斯的決定在多大程度上是基于比賽日的表現(xiàn)而非排位賽。