Total Members Voted: 502
Here is pretty good video that explains (among other things) Full Flow Staged Combution cycle:
Quote from: spacenut on 07/27/2017 01:23 pmWhere does SpaceX test this sub-scale engine? Will they attempt to see what it's maximum thrust can be?Also, can they test a full scale engine at McGregor? Or do they need Stennis? SpaceX tests their subscale Raptor at their McGregor test facility in Texas. I think that they will also test the full size Raptor at McGregor as well.
Where does SpaceX test this sub-scale engine? Will they attempt to see what it's maximum thrust can be?Also, can they test a full scale engine at McGregor? Or do they need Stennis?
RESPONSIBILITIES: Engineering, design, analysis, material/component selection and procurement, construction, activation, and maintenance of test stands, tooling, and supporting infrastructure Provide support and direction to technicians during construction, activation, and maintenance of stands and equipment Support testing campaigns by operating ground propellant systems, reviewing data for system health, and modifying equipment or procedures as necessary Develop novel ways to streamline site-wide processes and increase the reliability and efficiency of testing operations Perform any additional tasks that ensure efficient and effective testing, as required It is sometimes necessary to perform hands-on work in all environments (heat, cold, rain), occasionally in tight quarters or at heightsBASIC QUALIFICATIONS: Bachelors degree in mechanical engineering, aerospace engineering or other engineering disciplinePREFERRED SKILLS AND EXPERIENCE: Masters degree in mechanical or aerospace engineering 3+ years of relevant experience in an industrial setting Fundamental understanding, intuition, and aptitude of fluid and/or structural design and analysis Creative ability to imagine and design from scratch, while retaining low cost, reliability, efficiency, and maintainability Experience where quick-thinking and problem solving plays a critical role Good response to challenges posed by short deadlines Ability to work in a high-concentration, high-stress environment, under possible extended work hours Acute attention to detail, ability to see interactions with other systems to avoid problems Intermediate skill level using Windows Operating Systems Intermediate skill level using Microsoft Office Intermediate skill level using CAD (NX a plus) Experience with high pressure and cryogenic fluid systems and components Experience producing drawings for welders and machine shop fabrication Machining, welding, other fabrication techniques, and general hands-on experience Experience in FEA or CFD modeling and analysis, with ability to verify by simplified hand calculations Piping and pressure vessel design experience per ASME code, work with flanges, gaskets, fasteners Instrumentation, testing, data review and analysis, verification against a modelADDITIONAL REQUIREMENTS: General physical fitness is required for some work areas, flight hardware typically is built in tight quarters and physical dexterity is required Physical effort including standing, lifting and carrying light weight such as materials or equipment. Must lift up to 30 pounds unassisted Occasionally exposed to work in extreme outdoor environments- heat, cold, rain Work performed in an environment requiring exposure to fumes, odors, and noise Must be available to work extended hours and weekends, which varies depending on site operational needs, flexibility required
Based on IAC 2017, we are now looking at much smaller Raptor, roughly 60% of IAC 2016.31 engines with 5400mT thrust. That's 1707kN per engine.And the chamber pressure now down to 250barIAC 2016, it was 300bar, 3050kN
Still thinking they'll go up to 300 eventually.
Saves a lot in dev. costs over IAC2016 size Raptor but I still think they still should have bit the bullet and gone with a larger Raptor to reduce booster engine no.
Quote from: titusou on 09/29/2017 08:46 amBased on IAC 2017, we are now looking at much smaller Raptor, roughly 60% of IAC 2016.31 engines with 5400mT thrust. That's 1707kN per engine.And the chamber pressure now down to 250barIAC 2016, it was 300bar, 3050kNSo looks like what was termed subscale Raptor that is undergoing testing is now the size of Raptor they will use. Saves a lot in dev. costs over IAC2016 size Raptor but I still think they still should have bit the bullet and gone with a larger Raptor to reduce booster engine no.
The test data given was a bit of a surprise to me. I had no idea they had progressed so much already!
Quote from: Dante80 on 09/29/2017 10:57 amThe test data given was a bit of a surprise to me. I had no idea they had progressed so much already!Appears they need more or larger tanks if they can only get a 40 sec run. Theyll need a lot more time running the Raptor.The blue exhaust and shock diamonds were fantastic. Still have a hard time imagining 31 of them on a vehicle.
I'm pretty sure this version of the Raptor will eventually produce 3 MN. Initially Merlin 1D had ~70% of block 5 levels; here's the difference is roughly the same.
For my personal understanding, is it correct that the change in mixture ratio makes the combustion colder, hence less pressure and ISP?Also, can someone please explain to me why they are going oxygen rich instead of fuel rich? I always thought a fuel rich environment would create lighter combustion elements, hence higher ISP for the same chamber temperature and pressure. Is that wrong?