Come le compagnie faranno fronte al caro-petrolio

[Dodicicilindri]

sarebbe possibile sfruttare le superfici alari e della fusoliera per ricoprire il tutto con celle solari e sfruttare l' energia ottenuta con motori elettrici che fanno girare eliche; potrebbe consentire di risparmiare una parte di carburante

e' una roba troppo fantasiosa ?

oppure partire con meta' serbatoi e rifornire in volo ?

[Autodelta85]

Inoltre leggevo che grandissima parte degli sprechi è causata da situazioni di intasamento degli aeroporti,situazioni in cui l'aereo è con motori e APU accesi e stanno fermi anche delle mezz'ore inutilmente perchè magari la pista è intasata, però ovviamente l'aereo ha già staccato,l'aria condizionata va tenuta accesa e bisogna tenere i motori pronti per beccare i 15s giusti per il decollo

anche qu icosa fare?decongestionare il traffico....

[Dodicicilindri]

In effetti bisognerebbe decongestionare gli aeroporti e gestire meglio il traffico, ma la vedo difficile la cosa.

P.S.: ho letto che per il taxi la quantità di carburante consumata può variare da 200 a 400 kg/h: davvero notevole! Per una compagnia che ha 1000 aerei, ridurre il tempo medio di attesa di 10 minuti, considerando 1000 decolli al giorno (cioè un solo volo al giorno per ciascun aereo della flotta) per 365 giorni equivarrebbe a 18.250.000 kg di jet fuel risparmiati. Mica male.

Modificato 12 Giugno 2008 da Dodicicilindri

[Dodicicilindri]

Qualche approfondimento sul "geared turbifan" progettato dalla Pratt & Whitney:

Il motore in questione è il PW8000.

normalmente il fan è accoppiato all'albero LP (Bassa Pressione) avendone dunque lo stesso numero di giri.

esso però è un compromesso perchè l'efficienza del FAN è migliore ad un numero di giri più basso.

Con la scatola di riduzione ad ingranaggi si può avere un rendimento migliore

Il riduttore permette al fan e alla turbina Lp che lo aziona di ruotare a velocità differenti, ognuno alla sua velocità ottimale. Il fan, soprattutto se di grande diametro, rende di più a velocità più basse. La turbina può essere fatta girare più velocemente, riuscendo a compiere più lavoro con minori stadi.

A questo link un articolo a riguardo:

http://www.flightglobal.com/articles/20 ... for-p.html

Dato che il rumore del fan è direttamente legato alla sua velocità periferica, un fan che ruoti più lentamente, proprio perchè è più efficiente, avrà una minore quota-parte della sua energia persa sotto forma di perturbazioni acustiche.

La chiave ideale sarebbe tenere la velocità periferica il più lontano possibile dalle condizioni soniche locali. Ovviamente dato che il fan deve accelerare un flusso non è possibile rallentarlo oltre un certo limite; quindi ci sono compromessi da fare.

Quì potete trovare un articolo su un geared fan e la presentazione dei risultati di misure fatte su un geared fan e su un altro sistema di compressione (inter-refrigerato) fatti per aumentare l'efficienza dei propulsori.

http://www.aviationindustrygroup.com/downloads/prattwhitneychanging-1682-1856.pdf

http://www.dglr.de/veranstaltungen/extern/aerodays2006/sessions/A_Sessions/A4/A43.pdf

Ovviamente anche questo sistema ha dei problemi. Il problema del geared fan è tutto sul riduttore, che con le potenze che deve trasmettere, è suscettibile di usura, oltre che sede di perdita di rendimento.

Comunicato stampa pubblicato sul sito di Pratt e Whitney, proveniente dal loro ufficio stampa:

Geared Turbofan™ Engine Completes Phase II Ground Testing, Cleared for First Flight

BERLIN AIR SHOW 2008 – May 28, 2008 – Pratt & Whitney’s Geared Turbofan demonstrator engine has completed Phase II ground tests and has been cleared for flight testing on Pratt & Whitney’s 747SP flying test bed mid-year. Phase II, which began in April at Pratt & Whitney’s advanced test facility in West Palm Beach, Fla., focused on engine performance and ground acoustics with the Geared Turbofan engine’s flight capable nacelle system. The engine completed 120 hours of testing during Phase II and has logged a total 250 hours since ground testing began in November 2007. Pratt & Whitney is a division of United Technologies Corp. (NYSE:UTX).

The ground test program has been a complete success and the Geared Turbofan engine has met or exceeded all performance targets,” said Bob Saia, Pratt & Whitney vice president, Next Generation Product Family. “This demonstrator engine has confirmed the laboratory results of our Fan Drive Gear System demonstrating excellent efficiency and operational characteristics. The double-digit reductions in fuel burn, engine noise, environmental emissions and operating costs we’ve targeted make the Geared Turbofan engine the best solution for the next generation of commercial aircraft.”

The Phase II test program included the acoustic measurements of the Geared Turbofan demonstrator engine. The tests measured the ground-level noise characteristics of the engine, which is expected to be 50 percent quieter than today’s engines and 20 dB quieter than International Civil Aviation Organization (ICAO) Stage 4 noise regulations. The testing used an array of 32 individual microphones around the engine test stand and 16 sound pressure transducers inside the engine to get accurate data for noise modeling.

Initial data from the ground acoustic testing show the Geared Turbofan engine is right on target,” Saia said. “The ground test noise data will be compiled with flight test measurements taken later this year to validate the Geared Turbofan engine’s noise signature. The significantly lower noise of the Geared Turbofan engine is a key benefit to airlines and operators, giving them increased flexibility for landing and takeoff at airports with heavy noise regulations.”

The Geared Turbofan engine is expected to set new standards in environmental performance and operating value for the next generation of commercial aircraft. In a Geared Turbofan engine, a state-of-the-art gear system allows the engine’s fan to operate at a different speed than the low-pressure compressor and turbine, resulting in greater fuel efficiency and a slower fan speed for reduced noise. The Geared Turbofan engine builds on more than 20 years of technology development with improvements in every major module.

In 2007, Pratt & Whitney’s Geared Turbofan engine was selected as the exclusive power for the new Mitsubishi Regional Jet and the proposed Bombardier CSeries. The Mitsubishi Regional Jet program was officially launched on March 28, 2008, with an order from All Nippon Airways. The CSeries program is expected to launch later this year. Both aircraft are scheduled to enter service in 2013.

Pratt & Whitney has more than 17,000 aircraft engines installed with hundreds of airlines around the world. Additionally, Pratt & Whitney is a leading participant in two joint venture companies that manufacture commercial aircraft engines: International Aero Engines, which makes the V2500 for the Airbus A320 family of aircraft, and the Engine Alliance, whose GP7200 engine is FAR 33 certified for the new Airbus A380.

Pratt & Whitney is a world leader in the design, manufacture and service of aircraft engines, space propulsion systems and industrial gas turbines. United Technologies, based in Hartford, Conn., is a diversified company providing high technology products and services to the global aerospace and building industries.

[stev66]

comunque i nouvi modelli sono anche pensati per aumentare la vita media dei componenti, proprio per diminuire il peso della manutenzione programmata a tempo ed ad ore di volo.

[Dodicicilindri]

comunque i nouvi modelli sono anche pensati per aumentare la vita media dei componenti, proprio per diminuire il peso della manutenzione programmata a tempo ed ad ore di volo.

[stev66]

Questo permettera' percio' di ridurre i costi di inutilizzo ( stoccaggio e manutenzione programmata ) e percio' di diminuire i voli senza gravare sui costi .

[Dodicicilindri]

Alla fin fne, dato che all'orizzonte non si vede nessuna tecnologia magica, per risparmiare sul combustibile non si può far altro che ottimizzare tutte le componenti di un aereo (aerodinamica, motori), cercare di risparmiare sul peso e ridurre sprechi come quelli di cui hai parlato tu.

[Dodicicilindri]

Intanto, in attesa di miglioramenti agli aeromobili, ecco come le compagnie USA stanno intervenendo: tagli alla flotta, al personale e nuove tasse per i passeggeri:

Aggressive measures for US Airways

Flight cuts, new passenger fees expected soon; layoffs possible

The Arizona Republic

US Airways will join the parade of fuel-frantic airlines as early as today and announce new passenger fees, flight cuts, potential layoffs and other cost-cutting moves.

The airline's board of directors is meeting to consider options to offset an estimated $2 billion-a-year higher fuel bill, Chief Executive Officer Doug Parker told shareholders Wednesday at the airline's annual meeting in Tempe.

On the fee front, company insiders say the airline, the first to charge for meals several years ago, is likely to be the first major airline to charge for soft drinks.

It is also expected to follow American Airlines' lead on charging for even one checked bag.

American's $15 fee for the first bag begins next week, just a short time after most major airlines started charging $25 for the second checked bag.

"I think we'll be aggressive on those fronts," President Scott Kirby said of the industry's move to a la carte pricing.

The impact on passengers will be significant in Phoenix, where US Airways is the busiest carrier, with more than 300 daily departures from Sky Harbor International Airport.

US Airways officials declined to offer specifics but said the entire business has been under examination as the industry deals with a financial crisis far worse than the fallout after 9/11.

"Suffice it to say everything is certainly on the table right now," Kirby said after the shareholder meeting.

Oil prices that have more than doubled in the past year are a big problem for the industry and "one we're going to need to address," Parker said. "A $2 billion hole is a rather large hole to dig out of."

Kirby said US Airways' flight cuts and the number of affected employees won't be of the magnitude of recent downsizings announced by United, Continental and American.

Each said it planned to cut seat capacity in the United States by double-digit percentages.

Continental said it was eliminating 3,000 positions; United, 1,500; and American, an undetermined number in the thousands.

To date, US Airways has announced cuts of only 2 to 4 percent in U.S. seat capacity in the second half of the year.

"There's less opportunity for us than others," Kirby said.

The biggest reason: The airline is restricted on how much it can cut back flying under labor agreements made after the US Airways/America West merger.

They dictate a minimum fleet size and flight hours for pilots and flight attendants.

It also can't just park planes like other carriers, because many of its planes are leased.

Another factor, Kirby said: US Airways has been cutting duplicate and unprofitable flights since the US Airways/America West merger three years ago.

More flight cuts are definitely on the way, though, and the upshot for passengers is higher fares.

"Two to 4 percent (the capacity cuts already announced) is probably not enough," Kirby said.

With oil prices spiking from roughly $60 a barrel a year ago to Wednesday's high of $138, the airline now spends an average $299 per passenger round trip on fuel alone, executives said Wednesday.

That compares with $151 in 2007 and $70 in 2000.

And that's only for fuel, which even at current prices still represents less than half the airline's costs.

To break even, US Airways said it needs to get $650 to $700 per passenger from a combination of higher fares and fees.

The airline is nowhere close to that figure.

[Autodelta85]

mio papà ha prenotato 2 giorni fa la vacanza estiva con la US Airways,ha fatto bene prima che si continui a speculare e speculare