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#20
by
joncz
on 12 Nov, 2014 22:21
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#21
by
roma847
on 13 Nov, 2014 09:29
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#22
by
DaveS
on 27 Nov, 2014 23:28
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Okay, thereafter the intertank is 270 inches long and 331 inches in diameter. But the diameter of the stringer area is slightly larger, but how much? [
I believe that the actual stringer structure+TPS adds around 3-4 inches to overall diameter of the I/T.
Edit:
My ET Q is approximate dimensions of the IFRs on the LH2 tank?
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#23
by
roma847
on 28 Nov, 2014 16:32
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Tanks Dave,
does your size correlate to the diameter of the insulating foam with roundings or the diameter with milled stringers?
Since when the roundings of the insulating foam were milled?
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#24
by
DaveS
on 28 Nov, 2014 16:50
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It's the entire deal (stringer structure+foam TPS applied).
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#25
by
roma847
on 28 Nov, 2014 21:50
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Dave, I had asked about the difference of the diameters of the rounded insulating foam and after milling off the roundings,
Source: NASAbut that will not matter very much, I guess?
Remains the question of whether the roundings of the insulating foam were milled from the beginning of the Shuttle program or later?
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#26
by
DaveS
on 30 Nov, 2014 00:24
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What roundings? The stringers are essentially V-shaped with the bottom point being the flat surface you see in the photos. The legs of the V is the sides.
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#27
by
DMeader
on 02 Dec, 2014 13:14
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What roundings? The stringers are essentially V-shaped with the bottom point being the flat surface you see in the photos. The legs of the V is the sides.
More like a trapezoid (trapezium) with the wider base being against the tank.
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#28
by
roma847
on 02 Dec, 2014 16:22
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Hello guys,
let me explain briefly and show what I mean by "rounding", which may be the wrong word.
When the insulating foam is applied to the Intertank, one sees these rounded shape over the stringers.
Source: spaceflightnow.comAnd these rounded shape is then milled, resulting in the final trapezoidal shape.
Source: NASAI'm interested in the diameter of the Intertank in the final trapezoidal shape, which should be slightly greater than the diameter of the normal ET.
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#29
by
Jim
on 02 Dec, 2014 16:45
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I'm interested in the diameter of the Intertank in the final trapezoidal shape, which should be slightly greater than the diameter of the normal ET.
Probably not going to find a number because I bet it wasn't a controlled dimension.
Just need to add the foam thickness dimension to the inter tank diameter without foam.
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#30
by
roma847
on 02 Dec, 2014 20:20
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Okay Jim, but who knows the foam thickness dimension of the intertank?
Is there anybody who has technical drawings of the ET, showing these dimensions?
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#31
by
DaveS
on 02 Dec, 2014 20:33
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According to my calculations the final diameter of the I/T with TPS applied is 334" (8.4836 m).
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#32
by
Jim
on 02 Dec, 2014 20:46
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Okay Jim, but who knows the foam thickness dimension of the intertank?
Is there anybody who has technical drawings of the ET, showing these dimensions?
You can guess within a 1/4 inch. .25 out of 334 inches is less than .075%. At 100 to 1 scale, that is less than the paper thickness.
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#33
by
DaveS
on 02 Dec, 2014 23:07
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After some more careful calculations, the final OD of the I/T with TPS applied is closer to 340" (8.636 m) rather than the 334" (8.4836 m) I wrote earlier.
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#34
by
roma847
on 03 Dec, 2014 22:50
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Hi Guys,
I have found a few new things that we should consider.
In this drawing, the diameter of the ET is indicated by
331 inches, and it looks like the overall ET diameter.
Source: http://www.capcomespace.net/dossiers/espace_US/shuttle/index.htmAnd now I found this
Source in which the thickness of the insulation with
1 inch is specified.
The skin of the External Tank is covered with a thermal protection system that is a 2.5-centimeter (1-inch) thick coating of spray-on polyisocyanurate foam.This would result in a diameter of the Intertank (with milled stringer TPS) to
333 inches.
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#35
by
DaveS
on 03 Dec, 2014 23:11
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This would result in a diameter of the Intertank (with milled stringer TPS) to 333 inches.
Not quite. The I/T is larger than the rest of the ET as the attached photo shows.
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#36
by
roma847
on 07 Dec, 2014 17:30
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Okay Dave, you could be right, I've also researched again.
The diameter specified in the last drawing with 331 inches (ET OSL) is the
Outside Diameter (Outer Skin Line), i.e. without stringers and foam insulation of the intertank, which one still need to add.
Source: spaceflightnow.comThe height of the stringers I've determined from this
PDF (p. 10),
which should be approx. 2 inches, and the thickness of the insulation should be approx. 1 inch in the milled state.
Accordingly, the diameter with stringers and insulation should be approx.
337 inches.
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#37
by
Hog
on 08 Dec, 2014 14:05
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If the external diameter is 337", but that TPS foam has peaks and valleys. Aerodynamically speaking, does that slightly larger intertank portion react similarily to a smooth surface with a diameter that is the average diameter of the peaks/valleys?
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#38
by
roma847
on 08 Dec, 2014 15:53
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As you can see on most images of
External Tank, the diameter in the range of
Intertank with the stringers is slightly larger, as one can see in this image and as Dave also correctly noticed already.
Source: NASAAs specified by
NASA, the skin of the ET is covered with a
Thermal Protection System that is a 2.5-centimeter (1-inch) thick coating of spray-on foam polyisocyanurates.
I suspect that this is meant by the diameter of the milled insulation, as to be seen in this picture.
Source: NASAUnfortunately I have not found a technical drawing of Intertank with milled insulation so far.
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#39
by
roma847
on 10 Dec, 2014 12:46
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I still have found this drawing of the ET,
Source: www.capcomespace.net/dossiers/espace_US/shuttle/index.htmwhich is one part of a NASA Collection
"ET Inboard/Outboard Profile (Sheet 1 of 7)" in the green frame. It includes a series of cross sections (red frames) A-A, B-B, C-C, ... S-S, that would surely help with more details, especially the sections
A-A and
B-B (SH 2) of the Intertank.
Unfortunately I have only therefrom sections G-G and K-K (SH 1).
Who knows or has these drawings with the other cross sections or knows the source where this sheet collection is to be found?
Thanks in advance.
