Note newlylong's response was re: SRB exhaust only per the context. I expect the RS-25 exhaust will be directed S (same as it was for STS). The geometry of the RS-25s might mean something different (a split of 2x2 N/S) but expect it to mimic STS.
No, all of the exhaust is going to the north, SRBs and RS-25s. No more wedge.
Quote from: PahTo on 02/09/2015 10:08 pmNote newlylong's response was re: SRB exhaust only per the context. I expect the RS-25 exhaust will be directed S (same as it was for STS). The geometry of the RS-25s might mean something different (a split of 2x2 N/S) but expect it to mimic STS.STS was split because of the sidemount
Following simulations using NASA Ames’ supercomputer, a deflector design – that could withstand the high heat from plume exhaust, that did not result in plume blow-back, and whose surface pressure was within design margin limits – was selected.
Quote from: Jim on 02/10/2015 12:05 amQuote from: PahTo on 02/09/2015 10:08 pmNote newlylong's response was re: SRB exhaust only per the context. I expect the RS-25 exhaust will be directed S (same as it was for STS). The geometry of the RS-25s might mean something different (a split of 2x2 N/S) but expect it to mimic STS.STS was split because of the sidemountTo be accurate, Saturn V used wedge-shaped flame-deflector as well. It was mobile, on rails as it wasn't tied into the pad's water deluge system like the STS flame deflector.
Quote from: DaveS on 02/10/2015 03:26 pmQuote from: Jim on 02/10/2015 12:05 amQuote from: PahTo on 02/09/2015 10:08 pmNote newlylong's response was re: SRB exhaust only per the context. I expect the RS-25 exhaust will be directed S (same as it was for STS). The geometry of the RS-25s might mean something different (a split of 2x2 N/S) but expect it to mimic STS.STS was split because of the sidemountTo be accurate, Saturn V used wedge-shaped flame-deflector as well. It was mobile, on rails as it wasn't tied into the pad's water deluge system like the STS flame deflector.But was Saturn's flame divided? It sure looks like it was in this picture. And if so, why won't SLS's be divided? It has all of it's exhaust in one central area like Saturn V, not offset like STS. And it will be about 1Mlbs more thrust at liftoff that Saturn V I'd always assumed 39A and 39B were set up the way they were because Saturn V had too much thrust to direct out just one flame port. N-1's pad was built with 3 flame ducts...I assumed for the same reason. But if SLS's thrust can all go out the north side, seems like that was an incorrect assumption. Why build the pad with two flame ducts then rather than just one if one can do the job?
I'm no engineer, but there is something inherently unsettling about deflecting all that energy in one direction (asymmetrically). Perhaps this could damage the launch platform?
Stop the nonsense. Nothing is going to be damaged and there is nothing inherently bad with a unidirectional flame.Simulations and testing to aid in design for things like this did not exist when Saturn and even STS were developed. The single trench is less complex, allows for easier inspection and will be cheaper to build.
Thanks all for the feedback. While we're in the general area of the trench, it will be interesting to see how the SLS sound suppression water system will be configured, given that:- SLS will be generating more acoustic energy that STS (I assume)- The spacecraft is at the top of the stack and inside a shroud, not down on the side and exposed
Quote from: newpylong on 02/11/2015 04:42 pmStop the nonsense. Nothing is going to be damaged and there is nothing inherently bad with a unidirectional flame.Simulations and testing to aid in design for things like this did not exist when Saturn and even STS were developed. The single trench is less complex, allows for easier inspection and will be cheaper to build.Yes, but we're talking a pad that's already built, not a new one they are going to build. And the way it's built is to allow for exhaust out two sides especially with use of the Saturn type MLP's as SLS will. Is it just today they are able to to in depth analysis of construction and determine that 39B was so over built that it can handle almost 9Mlbs of thrust out either side? Something they'd couldn't be certain of in the 60's so they just added a lot of margin? Or something else?I'm still trying to get the "why" of only using one side of an existing pad that already has two flame ports. I understand the "why" of a new pad to only have one port with cost and simplicity.
Quote from: Lobo on 02/11/2015 05:02 pmQuote from: newpylong on 02/11/2015 04:42 pmStop the nonsense. Nothing is going to be damaged and there is nothing inherently bad with a unidirectional flame.Simulations and testing to aid in design for things like this did not exist when Saturn and even STS were developed. The single trench is less complex, allows for easier inspection and will be cheaper to build.Yes, but we're talking a pad that's already built, not a new one they are going to build. And the way it's built is to allow for exhaust out two sides especially with use of the Saturn type MLP's as SLS will. Is it just today they are able to to in depth analysis of construction and determine that 39B was so over built that it can handle almost 9Mlbs of thrust out either side? Something they'd couldn't be certain of in the 60's so they just added a lot of margin? Or something else?I'm still trying to get the "why" of only using one side of an existing pad that already has two flame ports. I understand the "why" of a new pad to only have one port with cost and simplicity.I answered your questions already as to why. Just because there are two it doesn't mean you need to use both.If you need further information I am sure it's out there direct from GSDO.
Quote from: newpylong on 02/11/2015 06:51 pmQuote from: Lobo on 02/11/2015 05:02 pmQuote from: newpylong on 02/11/2015 04:42 pmStop the nonsense. Nothing is going to be damaged and there is nothing inherently bad with a unidirectional flame.Simulations and testing to aid in design for things like this did not exist when Saturn and even STS were developed. The single trench is less complex, allows for easier inspection and will be cheaper to build.Yes, but we're talking a pad that's already built, not a new one they are going to build. And the way it's built is to allow for exhaust out two sides especially with use of the Saturn type MLP's as SLS will. Is it just today they are able to to in depth analysis of construction and determine that 39B was so over built that it can handle almost 9Mlbs of thrust out either side? Something they'd couldn't be certain of in the 60's so they just added a lot of margin? Or something else?I'm still trying to get the "why" of only using one side of an existing pad that already has two flame ports. I understand the "why" of a new pad to only have one port with cost and simplicity.I answered your questions already as to why. Just because there are two it doesn't mean you need to use both.If you need further information I am sure it's out there direct from GSDO.Having a single side flame deflector means that there is no leading edge that has to take the brunt of the exhaust.
Quote from: Jim on 02/11/2015 07:04 pmQuote from: newpylong on 02/11/2015 06:51 pmQuote from: Lobo on 02/11/2015 05:02 pmQuote from: newpylong on 02/11/2015 04:42 pmStop the nonsense. Nothing is going to be damaged and there is nothing inherently bad with a unidirectional flame.Simulations and testing to aid in design for things like this did not exist when Saturn and even STS were developed. The single trench is less complex, allows for easier inspection and will be cheaper to build.Yes, but we're talking a pad that's already built, not a new one they are going to build. And the way it's built is to allow for exhaust out two sides especially with use of the Saturn type MLP's as SLS will. Is it just today they are able to to in depth analysis of construction and determine that 39B was so over built that it can handle almost 9Mlbs of thrust out either side? Something they'd couldn't be certain of in the 60's so they just added a lot of margin? Or something else?I'm still trying to get the "why" of only using one side of an existing pad that already has two flame ports. I understand the "why" of a new pad to only have one port with cost and simplicity.I answered your questions already as to why. Just because there are two it doesn't mean you need to use both.If you need further information I am sure it's out there direct from GSDO.Having a single side flame deflector means that there is no leading edge that has to take the brunt of the exhaust.And that certainly makes sense as well.Why did Saturn V divide it's thrust then rather than just have it all go out the north as well?