Merlin-1

[Apollo13]

In terms of performance upgrades, we also have a number of those. The Merlin engines, the engine thrust is going to increase by approximately 8%, to 190,000 pounds of thrust at sea level. We think there's probably a little more room there, maybe going up to 10% or so. As well as some small increases in specific impulse of a few seconds. So both the efficiency of the engine and the thrust of the engine have increased. While not increasing, we haven't made any material change to the mass of the engine. So the thrust-to-weight of the engine is getting clearly incredible at this point. It was already the highest thrust-to-weight engine in the world and now it's got even... So. The vacuum version of Merlin increased in thrust by about 5%, to 210,000 pounds-force. Sorry, to 220,000 pounds-force. But we will be de-throttling this engine on this first flight, to assess the vibration increase in the environment, so it will currently be operating at its old thrust level. Just throttling down, essentially. It's a new engine operating at 5% below its rated thrust. So we'll be operating it at 210,000 pounds of thrust. But that's something we expect to increase by 5%, maybe 10% down the road. We are, again, very careful about the level of expansion of the thrust of the engines.

[Seerndv]

- а они уже близко подобрались к  пределу 110 атм, как писал ув. тов. Salo?

[Apollo13]

Краткое содержание выступления Тома Мюллера

https://www.reddit.com/r/spacex/comments/8lu8mf/tom_mueller_space_pioneer_award_ceremony_at_isdc/

[TH]Tom Mueller Space Pioneer Award Ceremony[/TH]International Space Development Conference (#ISDC)
by Parabolicarc.com via their twitter:
Tom Mueller [SpaceX Propulsion CTO] acceptance speech:

[/li]
• Thanks to NSS for this award. #ISDC
• Started in May 2002 at #SpaceX.
• Merlin 1A to Merlin 1C to Merlin 1D -- found a lot of smart young engineers #ISDC
• First task, develop a gas generator 00\99 used XCOR test stand to set up in Mojave. Ran 90 second test.
• Only propulsion person among 9 initial employees -- had a very hard time hiring people, co-workers at TRW said they would fail and that he'd end up back there.
• Limited at Mojave airport in how much they could test, took over old Beal Aerospace test site in Texas. Merlin Thrust Chamber Test -- celebrated with cognac --got pulled over speeding, but officer let them go.
• Did 1 test, but XCOR people said he didn't plan to do more than 1 per day. But, it was only 11 a.m. so they scrambled and did more tests.
• An employee who was a falconer suggested naming the engine after a falcon. Merlin is a medium sized falcon. The rocket is named after Millennium Falcon from Star Wars.
• Some early problems with flame duct on test stand.
• Tried to launch from Vandenberg, Atlas V with classified payload had to go to Marshall Islands. First three launches failed, fourth succeeded.
• Upgraded Merlin 1D more powerful, cheaper to build and can deep throttle for landings.
• Merlin holds the thrust to weight record now, but Raptor's coming.
• Making engine fly 10x you run into "100,000 mile problems" seals wear out, turbine blades and combustion chamber cracks....
• End of speech. Tweet with some nice pictures.
  

[Сергей]

И ничего ни про прототип Раптора, ни про Раптор, кроме - Раптор идет (в яндекс переводчике). Жаль.

[Apollo13]

https://www.youtube.com/watch?v=vVQyZn-VtXU

Tom Mueller (SpaceX) Explains The Merlin Rocket Engine

https://www.youtube.com/watch?v=vVQyZn-VtXU

Видео 2015 года. Цифры явно взяты с потолка.

[Apollo13]

https://www.geekwire.com/2018/spacex-propulsion-guru-tom-mueller-looks-ahead-rocket-engines-mars/

SpaceX propulsion guru Tom Mueller looks ahead to Raptor rocket engines for Mars

BY ALAN BOYLE on May 24, 2018 at 8:56 pm



Tom Mueller, SpaceX's propulsion chief technology officer, meets his fans at the International Space Development Conference in Los Angeles. (GeekWire Photo / Alan Boyle)

LOS ANGELES — SpaceX's success owes a lot to the tenacity of the company's billionaire founder, Elon Musk, but some of the credit has to go to the guy who designed the engines that make the rockets go.
That would be Tom Mueller, who was one of SpaceX's first employees back in 2002 and now serves as its propulsion chief technology officer.
Today Mueller recounted the creation of SpaceX's Merlin engines, and dropped some hints about the more powerful Raptor engines to come, while picking up a Space Pioneer Award here at the National Space Society's International Space Development Conference.
Before signing on with SpaceX, Mueller spent 15 years at TRW, where he was in charge of propulsion and combustion products and liquid rocket engine development.
Musk gave Mueller and his team the task of building the rocket engines that would power SpaceX's Falcon rockets, which derived that name fr om the Millennium Falcon of "Star Wars" fame.
An engineer at Barber-Nichols, a firm that partnered with SpaceX in the early days, happened to be a falconer — and she suggested that SpaceX's engines could be named after kinds of falcons.
That's how SpaceX's smallest engine came to be known as the Kestrel, one of the smallest breeds of the bird. The larger engine was named after a larger falcon: the Merlin.
The Merlin rocket engine has gone through several iterations under the guidance of Mueller and his teammates. The latest iteration, the Merlin 1D, revolutionized spaceflight when it entered service in 2013.

"This is a world-class engine," Mueller said. "This is very easy to make, very low-cost and extremely reliable. Very proud of it. And another thing that this engine had designed into it was fast and deep throttling. Fast and deep throttling allowed us to land the rocket, so this basically enabled recovery of the vehicles."
Over the past couple of years, the sight of SpaceX's reusable rockets landing themselves on oceangoing platforms or Florida landing zones has become routine. Reusability already has trimmed the $60 million price tag for a Falcon 9 launch by $10 million, Musk said this month, and there's more savings to come.
The Merlin 1D's performance has been tweaked for SpaceX's upgraded Falcon 9 Block 5 rockets, raising the engine's liftoff thrust to 190,000 pounds. SpaceX's propulsion team is also aiming for the engines to be reused up to 10 times before retirement.
Mueller compared the challenge to automobile maintenance.
"Now we're getting '100,000-mile' problems, wh ere you see blade-cracking ... wearing out seals, thrust chambers cracked," he said. "We're more into the 100,000-mile problems, not the infant mortality problems or the design problems."
Mueller is confident that the problems will be solved, but he's already shifting his attention to the next big thing.
"I've been working on Mars for the last four years, so I'm not going to take any credit for the Block 5 engine and all the upgrades that have happened," he said. "I'll take credit for developing the team that developed the Merlin 1D engine."
When Mueller says he's been working on Mars, he means that he's been working on the Raptor rocket engine for SpaceX's Mars transport spacecraft, known as the Big Frickin' Rocket or BFR.

The methane-fueled Raptor is expected to be twice as powerful as the Merlin 1D, with liftoff thrust of 380,000 pounds. The BFR's first-stage booster will use 31 of the engines to pack more punch than the Saturn V did during the Apollo era.
Mueller told GeekWire that he's been mulling over the Raptor for about a decade. The engine doesn't make use of the Merlin design, but goes instead with a full-flow, staged-combustion system that requires a clean-sheet design.
Engine development is on track for next year's anticipated start of short-hop flight tests of the BFR upper-stage spaceship.
"I don't want to say too much. We're building up the test stand right now. We've got the first flight version of that engine in work. We've been running the development engine quite a bit. It's running great," Mueller told the audience.
"The Merlin holds the thrust-to-weight record for now," he said. "But the Raptor's coming."

[Max Andriyahov]

"But the Raptor's coming."

[Apollo13]

[/li]
• Посадка стала возможна благодаря быстрому и глубокому дросселированию
• Том уже 4 года работает над Раптором и не участвовал в доработках Мерлина
• Дизайн Раптора отличается от Мерлина. Замкнутая схема газ-газ. Насчет штифтовой форсунки ничего не сказано.
• Разработка Раптора идет по плану, чтобы начать летные испытания в следующем году.
• Сейчас строится тестовый стенд 
• Первая версия летного двигателя "в работе".
• Тестовый двигатель работает хорошо.
  

[Apollo13]

I heard his talk. A few additional points:
Tom's colleagues at TRW thought he was crazy to take the SpaceX job. He tried to convince some of them to join him, but they weren't interested. That's when he decided to hire young people just out of school, who were hungry and unaware of the incredible odds facing them.
He showed a photo of the McGregor test stand (left over from Beal days) that they did the early engine tests on. Since the facility didn't have a water-dump system, the early Merlin engine tests blasted out a huge crater through the very thick concrete pad (and a considerable hole in the dirt underneath). The team had to get the concrete pad replaced each time they tested, until they finally got a water-dump system in place.
Also at McGregor, the team learned quickly to not stand anywhere near the open field downrange from the test stand. A few early tests sent engine parts flying a considerable distance.

Пока не сделали систему полива бетонный газоход на стенде был одноразовым  

[Сергей]

Apollo13 пишет:
Посадка стала возможна благодаря быстрому и глубокому дросселированию

Несомненно, молодцы.

Apollo13 пишет: 
Том уже 4 года работает над Раптором и не участвовал в доработках Мерлина

И далее, фраза, что не несет ответственности за изменения в двигателе блока 5. Имеются проблемы?

Apollo13 пишет:
Дизайн Раптора отличается от Мерлина. Замкнутая схема газ-газ. Насчет штифтовой форсунки ничего не сказано.

Ну штифтовой форсунки там и не может быть.

Apollo13 пишет:
Разработка Раптора идет по плану, чтобы начать летные испытания в следующем году.

Интересно, что он имеет ввиду - Раптор или прототип Раптора? Частенько, трактуют , что это один хрен, но это не так.

Apollo13 пишет:
Тестовый двигатель работает хорошо.

Работает - оно понятно, прототип и на пониженном давлении в КС.
Пожелаем удачи.

[Apollo13]

Сергей пишет:
И далее, фраза, что не несет ответственности за изменения в двигателе блока 5. Имеются проблемы?  

Наоборот хвалит команду, которая им занималась.

Сергей пишет:
Интересно, что он имеет ввиду - Раптор или прототип Раптора? Частенько, трактуют , что это один хрен, но это не так.

Для прототипа не нужен был бы новый стенд.

[Apollo13]

И летный двигатель уже по определению не прототип.

[Сергей]

Apollo13 пишет:

Сергей пишет:
Интересно, что он имеет ввиду - Раптор или прототип Раптора? Частенько, трактуют , что это один хрен, но это не так.

Для прототипа не нужен был бы новый стенд.

Apollo13 пишет:
И летный двигатель уже по определению не прототип.

Из этого можно сделать вывод , что к испытаниям Раптора не приступали? И что за ЛИ тогда? История не знает случаев отработки мощного ЖРД за год-полтора, я уж не говорю по схеме газ-газ.

[Apollo13]

Сергей пишет:

Apollo13 пишет:

Сергей пишет:
Интересно, что он имеет ввиду - Раптор или прототип Раптора? Частенько, трактуют , что это один хрен, но это не так.

Для прототипа не нужен был бы новый стенд.

Apollo13 пишет:
И летный двигатель уже по определению не прототип.

Из этого можно сделать вывод , что к испытаниям Раптора не приступали? И что за ЛИ тогда? История не знает случаев отработки мощного ЖРД за год-полтора, я уж не говорю по схеме газ-газ.

Разница между 100 и 160 тонным двигателем должна быть не так уж велика.

[Сергей]

Apollo13 пишет:

Сергей пишет:

Apollo13 пишет:

Сергей пишет:
Интересно, что он имеет ввиду - Раптор или прототип Раптора? Частенько, трактуют , что это один хрен, но это не так.

Для прототипа не нужен был бы новый стенд.

Apollo13 пишет:
И летный двигатель уже по определению не прототип.

Из этого можно сделать вывод , что к испытаниям Раптора не приступали? И что за ЛИ тогда? История не знает случаев отработки мощного ЖРД за год-полтора, я уж не говорю по схеме газ-газ.

Разница между 100 и 160 тонным двигателем должна быть не так уж велика.

Конструктивно могут быть весьма близки, только к сожалению каждый типоразмер отрабатывается экспериментально на предмет устойчивости горения, то есть ограничение амплитуды колебаний давления на всех рабочих режимах, на низких частотах - примерно 100-200 гц, средних - 200-500, высокочастотных - до нескольких тысяч гц. И решения, обеспечившие успех , для одного типоразмера с ростом давления могут быть недостаточны при повышении давления в КС, и также недостаточны при увеличении типоразмера.

[Apollo13]

https://spacenews.com/safety-panel-warns-schedule-for-commercial-crew-test-flights-still-uncertain/

SpaceX has also been addressing an issue with the Falcon 9's Merlin 1D engine. Examination of some of the first engines found anomalies that were "potentially dangerous, and certainly not desirable," said ASAP member Donald McErlean. SpaceX and NASA have worked on a test plan to address the problem.

SpaceX and NASA, he said, have come up "two principal courses of action in the short term" to correct the problem and two others that would require more modifications to the engine. "The risk is low enough with the two short-term modifications to use those for powering the uncrewed test," he said, "and the decision for powering the crewed test would come later." He didn't elaborate on those courses of action, but said that the panel was "optimistic those courses of action will result in a satisfactory conclusion."

[Apollo13]

https://www.nasaspaceflight.com/2018/07/asap-boeing-failure-positive-spacex-crew-announcement/

Another area to watch – one that ASAP believes is on course to a "satisfactory conclusion" – relates the Falcon 9's Merlin 1D engines and their upgrades for crew configuration.  "The first two engine started to go through the qualification procedure, and upon tear down there were observations of some anomalies in the hardware that were considered potentially dangerous – certainly not desirable," noted the ASAP.

"There was a program undertaken to try to modify the design and to correct these anomalies.  SpaceX and NASA agreed on a requalification plan that actually includes six engines – two ground test configurations and one in-flight test configuration."


As work on this issue continued, SpaceX developed two short-term corrective actions that are deemed worthy and safe to fly on the uncrewed DM-1 mission.  At the same time, SpaceX began designing and implementing two longer-term solutions to the anomaly seen on the test stand.

The ASAP noted that the two short term actions could also potentially be used on the crewed DM-2 flight should they prove safe enough during post-flight and post-test stand teardown and inspections.  A decision on whether those short-term actions can fly on the crew demonstration mission will not be taken until a better understanding of the short-term actions are known.

Nonetheless, the ASAP is "optimistic that those courses of action will result in a satisfactory conclusion."

[Старый]

Вряд ли при схеме газ-газ возникнут ВЧ-колебания.

[Salo]

А в газогенераторах?

[Старый]

Salo пишет:
А в газогенераторах?

В газогенераторах уже легче.