SABRE (rocket Engine) - Performance

Performance

The designed thrust/weight ratio of SABRE ends is high—up to 14—compared to about 5 for conventional jet engines, and just 2 for scramjets. This high performance is a combination of the cooled air being denser and hence requiring less compression, but more importantly, of the low air temperatures permitting lighter alloy to be used in much of the engine. Overall performance is much better than the RB545 engine or scramjets.

The engine gives good fuel efficiency peaking at about 3500 seconds within the atmosphere. Typical all-rocket systems are around 450 at best, and even "typical" nuclear thermal rockets only about 900 seconds.

The combination of high fuel efficiency and low mass engines means that a single stage to orbit approach for Skylon can be employed, with air breathing to mach 5.14+ at 28.5 km altitude, and with the vehicle reaching orbit with more payload mass per take-off mass than just about any non-nuclear launch vehicle ever proposed.

Like the RB545, the precooler idea adds mass and complexity to the system, normally the antithesis of rocket design. The precooler is also the most aggressive and difficult part of the whole SABRE design. The mass of this heat exchanger is an order of magnitude better than has been achieved previously; however, experimental work has proved that this can be achieved. The experimental heat exchanger has achieved heat exchange of almost 1 GW/m³, believed to be a world record. Small sections of a real precooler, referred to as modules, now exist.

The losses from carrying the added weight of systems shut down during the closed cycle mode (namely the precooler and turbo-compressor) as well as the added weight of Skylon’s wings would appear to be heavy, yet the gains in overall efficiency more than make up for this. These losses are greatly offset by the different flight plan. Conventional launch vehicles such as the Space Shuttle usually start a launch by spending around a minute climbing almost vertically at relatively low speeds; this is inefficient, but optimal for pure-rocket vehicles. In contrast, the SABRE engine permits a much slower, shallower climb, air breathing and using wings to support the vehicle, giving far lower fuel usage before lighting the rockets to do the orbital insertion.

Read more about this topic:  SABRE (rocket Engine)

Other articles related to "performance":

35th Tony Awards - Winners and Nominees
... Monty Norman and Julian More – The Moony Shapiro Songbook Mary Kyte – Tintypes Best Performance by a Leading Actor in a Play Best Performance by a Leading Actress in a Play Ian ...
Rent (musical) - Productions - Original Broadway Production
... The production's controversial topics and innovative pricing, including same day-of-performance $20 tickets, helped to increase the popularity of musical theater amongst the younger generation ... won four Best Musical, Best Book, Best Original Score and Best Performance by a Featured Actor in a Musical (Heredia) On April 24, 2006, the original Broadway cast reunited for a one-night performance of ... This performance raised over $2,000,000 for the Jonathan Larson Performing Arts Foundation, Friends In Deed and New York Theatre Workshop ...
R. Kelly - Grammy Awards
... Year Nominated Song of the Year Nominated Best Male R B Vocal Performance Won Best R B Song Won Best Song Written for a Motion Picture, Television or Other Visual Media ... Best R B Album Nominated "Satisfy You" Best Rap Performance by a Duo or Group Nominated 2001 "I Wish" Best Male R B Vocal Performance Nominated 2003 "The World's Greatest ...
Cyrix 6x86 - Performance
... Cyrix used a PR rating (Performance Rating) to relate their performance to the Intel P5 Pentium (pre-P55C), because a 6x86 at a lower clock rate outperformed ... an entirely truthful representation of the 6x86's performance ... While the 6x86's integer performance was significantly higher than P5 Pentium's, it's floating point performance was more mediocre—between 2 and 4 times the performance of the 486 FPU per clock cycle(depending ...

Famous quotes containing the word performance:

    Still be kind,
    And eke out our performance with your mind.
    William Shakespeare (1564–1616)

    So long as the source of our identity is external—vested in how others judge our performance at work, or how others judge our children’s performance, or how much money we make—we will find ourselves hopelessly flawed, forever short of the ideal.
    Melinda M. Marshall (20th century)

    Nobody can misunderstand a boy like his own mother.... Mothers at present can bring children into the world, but this performance is apt to mark the end of their capacities. They can’t even attend to the elementary animal requirements of their offspring. It is quite surprising how many children survive in spite of their mothers.
    Norman Douglas (1868–1952)