Холивар Raptor vs РД0164, Мюллер vs Рачук

[Старый]

Дмитрий В. пишет:

Старый пишет:
Зато на воде - абсолютная пожаробезопасность.    Удивительно - как счас про ту схему не вспомнили?

А зимой, в мороз?

А там фича в том что перед включением двигателя воду надо нагревать. И наче двигатель даже без зимы слишком медленно выходит на режим.

[Старый]

октоген пишет:
Старый... Убейся... , .

Счаззз!

Есть патенты где в ГГ напряженного движка предлагают жидкий гелий впрыскивать

Что ещё предлагают в патентах? 

Вместо холодного антифриза в принципе подойдет и жидкий азот

А сколько можно набрать патентов на разные составы охлаждающих жидкостей!

 Да, роста УИ, как с гелием не будет, но это всяко дешевле фейерверков при пусках.

Дешевле всего НЕ НАГРЕВАТЬ смесь до температуры возгораемости.  А нагревать а потом охлаждать это для изобретателей типа вас. 
 Причём что примечательно: вся тупость предлагаемой вами идеи до вас так и не дошла. 

[m-s Gelezniak]

Дмитрий В. пишет:

Apollo13 пишет:

Salo пишет:
Тему можно закрывать: наши креативные гении вместо метанового двигателя на 300 тс нацелились на 83 тонную керосинку открытой схемы.
Писец - "бег на месте общеукрепляющий".

Мне кажется рано посыпать голову пеплом. Это всего лишь разговоры. Или нет?

Это всего лишь один из вариантов, рассматривающихся в ЦиХ.

A-aa... .
 

[Bell]

m-s Gelezniak пишет:
в ЦиХ.

Что самое доставляющее в этой ситуации

[октоген]

Старый пишет:

октоген пишет:
Старый... Убейся... , .

Счаззз!

Есть патенты где в ГГ напряженного движка предлагают жидкий гелий впрыскивать

Что ещё предлагают в патентах?

Вместо холодного антифриза в принципе подойдет и жидкий азот

А сколько можно набрать патентов на разные составы охлаждающих жидкостей!

Да, роста УИ, как с гелием не будет, но это всяко дешевле фейерверков при пусках.

Дешевле всего НЕ НАГРЕВАТЬ смесь до температуры возгораемости. А нагревать а потом охлаждать это для изобретателей типа вас.
 Причём что примечательно: вся тупость предлагаемой вами идеи до вас так и не дошла.

Не, Старый, ты из-за своей наглости не вкуриваешь, что предлагается доработка УЖЕ ИМЕЮЩЕГОСЯ двигателя. Без новых эпопей на миллиарды.

[Старый]

октоген пишет:
Не, Старый, ты из-за своей наглости не вкуриваешь, что предлагается доработка УЖЕ ИМЕЮЩЕГОСЯ двигателя. Без новых эпопей на миллиарды.

Это точно. Я не курю. Тем более такое.

[kp_]

Shestoper пишет:

октоген пишет:
Ну а разрабатывать метановый 300-тонник, при том что
метан позволяет 2-3 килотонник сделать-это полный
дебилизм.

Открытой схемы под низкое давление в КС -
позволяет. Но и керосин позволяет, хоть с кислым ТНА, хоть со сладким.
Четыре камеры от F-1 и ТНА с мощностью как у РД-170.

Но такой
двигатель будет узко заточен - под первую ступень супертяжа. И для его создания
нужны немалые инвенстиции, ввиду его размерности. Например сейчас просто нет
стендов для его прожига. А стенд понадобится циклопический, масштабов УКСС.
В условиях вышеупомянутой мышиной возни такие дела не делаются.

Подсказали бы Маску! А то он бедный бегает мучается, не знает, на чем марсианскую ракету строить, дал обратный ход от 300-тонника!

[kp_]

октоген пишет:
Ну а разрабатывать метановый 300-тонник, при том что метан позволяет 2-3
килотонник сделать-это полный дебилизм.

Это кому позволяет? Пойдите расскажите это НАСА, или Маску, думаю они от вас не отстанут, с предложением денюшек, в обмен на (сту..) движки.

[Старый]

kp пишет: Пойдите расскажите это НАСА, или Маску, думаю они от вас не отстанут, с предложением денюшек, в обмен на (сту..) движки.

Вот ведь что может получиться если опровергатель вдруг попытается подумать...

[Salo]

http://www.nasaspaceflight.com/2014/03/spacex-advances-drive-mars-rocket-raptor-power/#.UxoIWvaJYI8.twitter
 

SpaceX officially revealed a R&D test program for the Raptor would begin at the Stennis Space Center, with company already working to upgrade the E-2 test stand with methane capability.

SpaceX engineers are understood to be close to completing the methane upgrades to the stand, although it is not currently known when Raptor hardware will be tested at the famous facility.
However, information on the Raptor was updated on February 19, when VP of Propulsion Development Tom Mueller – speaking at the "Exploring the Next Frontier: The Commercialization of Space is Lifting Off" event in Santa Barbara, California - revealed the Raptor had mutated to a 1Mlbf (4,500kN) gas-gas (full flow) liquid methane and oxygen engine, with an isp of 321s at sea level 363s at vacuum.


Mr. Mueller confirmed nine of these engines would power each 10 meter diameter core of the notional MCT. "I'm quite proud to have my name attached to this engine," said the SpaceX Co-Founder at the event.
The implications of this revelation are numerous – the most important being SpaceX are now fully treading into uncharted territory.

[Seerndv]

http://www.spaceflight101.com/spacex-launch-vehicle-concepts.html
А по эволюциям Раптора это было?  ( свести бы все метановые в одну тему)

Raptor Engine Family

irst presented in 2009 by SpaceX, the Raptor engine started out as a LO F X/LH2 powered engine design for upper stages. The engine was proposed to have a vacuum impulse of 470 seconds achieving a thrust of 667 Kilonewtons (68,000kgf) with a throttle range of 50 to 100%. Optimized for operation in vacuum, Raptor would have flown with an extended nozzle with an area ratio of 250:1.

 Unlike the Merlin rocket family, the Raptor was initially conceptualized to be a cryogenic staged combustion engine with a closed cycle. The majority of LH2 fuel and a portion of the oxidizer flow is fed at high pressure to the pre-burner that burns the propellants and supplies hot gas to two separate turbines that are used to power the LH2 and LOX turbopumps.

 The exhausted fuel-rich gas is then injected into the combustion chamber with the rest of the oxidizer to complete the combustion. A portion of the fuel is used for engine cooling (regenerative cooling) before being injected into the engine as well.


Image: Purdue University/Spaceflight101

 

Raptor was designed to operate at a chamber pressure of 117 bar. The Raptor engine characteristics as of 2010 are given in the table at the bottom of this page.

In 2012, the Raptor development program got underway after a change in direction as SpaceX's Elon Musk announced that Raptor would become a family of methane-fueled engines. No longer designed for exclusive use on upper stages, different versions of Raptor would be used as first stage and upper stage engines, not unlike the Merlin 1 engines that are used on Falcon 9's first stage and as a vacuum-optimized version on the second stage.

 With the switch fr om LH2 to methane, Raptor's design thrust was drastically increased for it to power large launch vehicles. This re-designed version of Raptor will keep its staged-combustion design, but use a Full-Flow cycle which has not been used for the 2010 Raptor design shown above.

A Full-Flow Staged Combustion Engine is a variation of the Staged Combustion Cycle (shown above) in which all of the oxidizer and fuel pass through their respective turbopump turbines. The fuel is first directed through the nozzle heat exchanger to provide regenerative cooling before being passed to the fuel turbine; the oxidizer flows directly fr om its turbopump to the LOX turbine. To power the turbines, a small amount of fuel & oxidizer is exchanged between the lines which then is then burned in two pre-burners (one oxidizer-rich, one fuel-rich) to deliver the hot gas to power the turbines that drive the turbopumps. The propellants are then fed to the combustion chamber wh ere the combustion process is completed.

 The advantage of the full-flow cycle is that the turbines operate at lower temperatures since more mass passes through them leading to increased reliability and a longer engine life which is particularly important to potential re-use of the engine. In addition, this engine design can deliver higher chamber pressures and improve the efficiency of the engine.

Image: Purdue University/Spaceflight101

 

Methane has a slight advantage over Rocket Propellant-1 in terms of specific impulse, but can not reach that of Hydrogen. However, there are other advantages over LH2 such as easier handling and storage, no concerns associated with Hydrogen embrittlement and a much lower production cost. In addition, liquid methane has a higher density than LH2 which has obvious implications for tank and vehicle dimensions. Compared to RP-1, methane does not lead to coking of the engines which is a common problem with RP-1 that requires oxygen-rich combustion to lim it coking, but creates a more corrosive environment.

In October 2013, SpaceX officially confirmed that the Raptor engine would be tested at NASA's Stennis Space Center. SpaceX personnel started working at test complex E at Stennis in mid/late 2013 to implement modifications needed to support methane engine tests. The E-2 complex can only facilitate engines up to 500kN which is sufficient for testing the individual components of the Raptor engine such as the Pre-Burner. 

For testing of the complete Raptor, a bigger test stand is needed. As of late 2013, testing at Stennis was expected to commence in 2014.

Fuel	Liquid Methane
Oxidizer	Liquid Oxygen
Sea Level Thrust	3,800 kN
Vacuum Thrust	4,400 kN
Isp (SL)	>320s
Isp (Vac)	>360s

In February 2014, Tom Mueller, SpaceX head of rocket engine development, elaborated on the design of future SpaceX vehicles and engines at an event in Santa Barbara. He stated that the Raptor engine that is currently being worked on would have a vacuum thrust of 4,400 Kilonewtons (448,700kgf) and achieve a vacuum impulse exceeding 360 seconds. Raptor would have an estimated  and Sea Level thrust of around 3,800 Kilonewtons (362,800kgf) or slightly less. With these figures, Raptor would reach a higher specific impulse than the Russian-designed RD-0162 methane-fueled engine.

- почтенный "перегрев" в курсе, особенно последнего?!  :oops:

[Mark]

With these figures, Raptor would reach a higher specific impulse than the Russian-designed RD-0162 methane-fueled engine

Посмотрим как будет если сделают за 3-4 лет РД-0162, пока УИ на 323,1 с.
Для РД-192 пишут про УИ на 333,4 с на уровне моря, давление в КС 210 кгс/см2.

[Salo]

Большой пишет:

[Seerndv]

Как-то неудобно напоминать, но уж тогда надо и топик по РД на метане обновить картинками  

[Димитър]

Данние про Раптора у вас уже устаревшие. Еще в июне 2014 тот самий Мюллер заявил, что тяга двигателя будет. 705 тонн на уровне моря и 840 т в вакууме. УИ + 321 сек и 363 сек соответно. Потом обещали увеличить до 380 сек.

[Salo]

Устаревшие данные у Вас: Маск в январе заявил, что тяга будет 230т, а УИ 380с у вакуумной версии.

[Димитър]

Salo пишет:
Устаревшие данные у Вас: Маск в январе заявил, что тяга будет 230т, а УИ 380с у вакуумной версии.

Это какой январь? 2015? Ссылочку можно? 

[Salo]

Highlights of Elon Musk's Reddit Ask Me Anything Session             
Posted by Doug Messier
on January 6, 2015, at 12:18 pm

Elon Musk (Credit: SpaceX)
 
SpaceX CEO Elon Musk did an interactive Ask Me Anything Q&A last night on Reddit. Here are some excerpts from that session.

Q. In your recent MIT talk, you mentioned that you didn't think 2nd stage recovery was possible for the Falcon 9. This is due to low fuel efficiency of kerosene fuel, and the high velocities needed for many payloads (high orbits like Geostationary orbit). However, you also said that full reusability would be possible for the Mars Colonial Transporter launch vehicle.
What have you learned fr om flights of Falcon 9 that taught you
a) that reuse of its second stage won't be possible and
b) what you'll need to do differently with MCT to reuse its second stage.

Elon Musk: Actually, we could make the 2nd stage of Falcon reusable and still have significant payload on Falcon Heavy, but I think our engineering resources are better spent moving on to the Mars system.
MCT will have meaningfully higher specific impulse engines: 380 vs 345 vac Isp. For those unfamiliar, in the rocket world, that is a super gigantic difference for stages of roughly equivalent mass ratio (mass full to mass empty).

Q. What kind of mass ratio do your upper stages have?

Elon Musk: With sub-cooled propellant, I think we can get the Falcon 9 upper stage mass ratio (excluding payload) to somewh ere between 25 and 30. Another way of saying that is the upper stage would be close to 97% propellant by mass.

Q. Has the Raptor engine changed in its target thrust since the last number we have officially heard of 1.55Mlbf SL thrust?

Elon Musk: Thrust to weight is optimizing for a surprisingly low thrust level, even when accounting for the added mass of plumbing and structure for many engines. Looks like a little over 230 metric tons (~500 klbf) of thrust per engine, but we will have a lot of them

Q. Emily Shanklin indicated in late 2013 that the Raptor would be the first of a "family of engines" designed for the exploration and colonization of Mars. Could you elaborate on her wording, i.e. was she simply referring to a vacuum version and standard version, or do you plan on building multiple methane-based engines with significantly different thrust and size specifications?

Elon Musk: Default plan is to have a sea level and vacuum version of Raptor, much like Merlin. Since the booster and spaceship will both have multiple engines, we don't have to have fundamentally different designs.
This plan might change.

[Salo]

Что характерно Blue Origin делает свой метановый BE-4 в том же классе тяги:
http://spacenews.com/41901ula-to-invest-in-blue-origin-engine-as-rd-180-replacement/

Blue Origin of Kent, Washington, has been developing the BE-4 engine for three years, thus giving it a head start against other prospective RD-180 replacements, ULA Chief Executive Tory Bruno said at a press conference here. Fueled by liquefied natural gas, the new engine will be relatively inexpensive to develop and build, and could be ready to start flying in four years, he said.

Bruno said developing a new main engine typically takes seven to 10 years and costs around $1 billion.
...
Bezos said during the press conference that the BE-4, which will generate about 550,000 pounds of thrust, is based on the BE-3 that powers Blue Origin's New Shepard, an experimental suborbital rocket that takes off and lands vertically. In addition to the Atlas 5 successor, the new engine would be used for a future reusable orbital launcher Blue Origin plans to develop, he said.
Two BE-4 engines generating a combined 1.1 million pounds of thrust at sea level would power the new rocket's first stage, Bruno said. The current Atlas 5 first stage is powered by a single RD-180 generating close to 1 million pounds of thrust.
...
In June, ULA announced that it had signed contracts with multiple unspecified companies to study alternatives to the RD-180. The company, a Boeing-Lockheed Martin joint venture, declined to identify any of the contract recipients but said a first launch of the new engine was targeted for 2019.

Bruno said the BE-4 came out as the winner in that competition.

[Димитър]

Salo пишет:  Маск в январе заявил, что тяга будет 230т, а УИ 380с у вакуумной версии.

 Мало для MCT. Получим аналог Н-1 от Маска?