How do YOU define "air-hoggy"

[bsalis]

There is no clear threshold between airhoggin and not airhoggin.

Personally I don't care how others choose to build craft. However if you're new to SSTO Spaceplanes, and just keep spamming intakes until you make it work, I think you are denying yourself a true understanding of what makes an SSTO Spaceplane tick. If that is not an objective then it's not a problem, but I think many people do think they know but really do not.

Fact is you can get to orbit with a 1:1 ratio. For a Challenge thread, I did it with *one intake* on a craft that had 3 jets. From my experience I would say that...

1:1 = hard mode

1.5:1 = workable but poor performance

2:1 = adequate

2.5:1 = ample

3:1 = plenty

4:1 = more than needed

If you can't get to orbit on a 4:1 ratio and the only goal is only to do that, then you are doing it wrong.

I have done a Duna return, non-stop, on a 3.2:1 ratio, and i'm sure it can be done on 3:1

[Oxytropis]

[Anton P. Nym]

I got a reasonable-looking 5:1 (and a later mark with 6:1) using the radial intakes, without clipping and with semi-plausible air flow. I try to make my spaceplanes not obviously absurd....

....well, usually. (My defense in this case; there are no stock ducted air fans or propellers in the game yet, particularly none driven by electricity, so the only stock option is ion engines for a solar-powered plane.)

-- Steve

Edited July 23, 2013 by Anton P. Nym
Fxing busted phrasing

[Firov]

For me I don't like to use more than 1 intake per jet engine, as it really doesn't make sense to me. I'll occasionally use an extra radial intake or two, but even that's rare anymore. As long as the jets can get me to around 23km at Mach 4 I don't mind relying on rockets for the rest. Luckily, the B9 Aerospace Variable Geometry Radial Engine Mounts make things easy for me these days. The below craft has one intake per jet engine and can pretty easily get 5.5 to 6.5 tons of cargo into orbit.

Edited July 23, 2013 by Firov

[Somerled]

I have only one design rule: to minimally engineer a craft for the desired mission.

The idea is that if I can't get to space, get to another planet, circumnavigate, or whatever my aim is, then the chances are higher that I'm simply flying it wrong, not designing it wrong. As I perfect my handling of every craft as much as possible, it turns out I can squeeze oodles of performance out of even the most underengineered flying bathtubs.

I save airhogs for my silly days, when my mission is just to create fire as fast and as often as possible.

[CleverClothe]

It has 120 intakes hidden in the engine pods

That is so far removed from feasible that we would have to invent a new term for it. I bet those jets could operate on the moon simply due to the gravitational anomaly of all those intakes sucking up oxygen from Kerbin's atmosphere.

[PotatoOverdose]

show me a craft with a 5:1 ratio (oh btw i mean ram-air intakes and circular intakes only) that looks feasible

Here's my SSTO, admittedly it has a 6:1 ratio but I think it looks feasible.

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Goes all the way to Laythe without refueling.

Stock (/w kerbal engineer), 60 Parts, 15 Tons, 6 air intakes.

The above album is an overview of my most recent flight.

[ecat]

How do I define air-hoggy?

I define air-hoggy like this...

http://forum.kerbalspaceprogram.com/showthread.php/35743-200-kerbal-tons-to-LKO-worth-it?p=451799&viewfull=1#post451799

http://forum.kerbalspaceprogram.com/showthread.php/35743-200-kerbal-tons-to-LKO-worth-it?p=452199&viewfull=1#post452199

http://forum.kerbalspaceprogram.com/showthread.php/35743-200-kerbal-tons-to-LKO-worth-it?p=463563&viewfull=1#post463563

I define 'subtle design' like this...

http://forum.kerbalspaceprogram.com/showthread.php/33503-Show-off-your-B9-Designs!?p=501586&viewfull=1#post501586 (second craft)

http://forum.kerbalspaceprogram.com/showthread.php/33503-Show-off-your-B9-Designs!?p=508910&viewfull=1#post508910

All the above have about the same engine to intake air ratio. All were great fun to build and I learned so much on the way. I guess you can call me shameless.

I think anyone with an idea for a dream ship, who stops and thinks 'but it will need one air intake more than is polite' or 'I can't do it because people will say it's air hoggy' - I was going to say that they are doing it wrong, but that would be unfair. It's your game, play it your way. That said, I designed the B9 Quindecim Cargo MkII d: Loly "Green Crayon" Edition (!), first craft second picture above, as a direct response to some who said a previous design looked too air hoggy, so maybe I'm not entirely cool with the conservative types.

Edited July 23, 2013 by ecat

[Eric S]

If you're making the wings longer not because you need more lift but because you need more room to mount air intakes, you might be air hogging.

This also applies if you're thinking that the craft classifications should include "flying air intake."

[Anton P. Nym]

That is so far removed from feasible that we would have to invent a new term for it. I bet those jets could operate on the moon simply due to the gravitational anomaly of all those intakes sucking up oxygen from Kerbin's atmosphere.

Not really. The TF39 turbofan engine for the real-life C-5 Galaxy has a ~250cm diameter, or roughly the same diameter as a KSP size 2 engine. There are no size 2 jet engines in KSP that I know of; the size 1 engines there are about half that diameter, and so only draw (as a rough approximation) a quarter the air. The Galaxy has 4 TF39s and each would need to have 4:1 intakes (16 in total) to match.

Air flow scales roughly by the square of the diameter; 60 intakes per pod would only need each pod to be 7-8 times the diameter of a size 1 engine... which isn't terribly far off, given the picture.

-- Steve

Edited July 23, 2013 by Anton P. Nym
argh, typos...

[pa1983]

That is so far removed from feasible that we would have to invent a new term for it. I bet those jets could operate on the moon simply due to the gravitational anomaly of all those intakes sucking up oxygen from Kerbin's atmosphere.

It only goes to 36km altitude with a max payload so not it would not, its quite limited by engine power if anything. And it has a 10:1 intake to engine ratio.

The nacelles could easily accommodated twice the number of intakes due to the need for a high lift capable wing, still the craft is some what lift (to few wigs) and engine power limited then anything else.

Edited July 24, 2013 by pa1983

[CleverClothe]

Not really. The TF39 turbofan engine for the real-life C-5 Galaxy has a ~250cm diameter, or roughly the same diameter as a KSP size 2 engine. There are no size 2 jet engines in KSP that I know of; the size 1 engines there are about half that diameter, and so only draw (as a rough approximation) a quarter the air. The Galaxy has 4 TF39s and each would need to have 4:1 intakes (16 in total) to match.

Air flow scales roughly by the square of the diameter; 60 intakes per pod would only need each pod to be 7-8 times the diameter of a size 1 engine... which isn't terribly far off, given the picture.

-- Steve

The C-5 has a 1:1 ratio (one intake per engine). The posted craft has 120 intakes and what looks like 12 engines. Those craft are not equivalent.

[Edit: But I can see how there are limitations in the current system where a 2:1 would imitate actual aircraft. Which is why I think 3:1 is the technical air-hogging line.]

Edited July 25, 2013 by CleverClothe

[The Destroyer]

Something that has 100 intakes on a small plane.

I generally aim for max 1 intake per 2 parts.