A Bio-Jet Pack? O.o

[Krüsher]

Hello playground! I wasn't sure where to put this because even though it is D&D related, it can just be a topic for general discussion. I was deciding to reflavor my character's abilities the other day, and thought of this: What if the organism had a sort of jet-pack that propelled it through the air, in place of wings? I was talking to a friend about it and I have come to the decision that it would be somewhat squid-like in the idea of sucking in air and shooting it back out. But I am still stuck on the mechanism for such a thing (It doesn't have to be natural in the sense of our idea of evolution, but he was mutated, not augmented.) I am open to new ideas for it, but keep in mind a ion cannon powered by blood plasma has already been thought of :smalltongue:

[Gwyn chan 'r Gwyll]

A bio-jet-pack, you say? (http://drmcninja.com/archives/comic/3p36/)

[Tebryn]

Take a read through this. (http://drmcninja.com/archives/comic/3p1/)

[Gwyn chan 'r Gwyll]

Take a read through this. (http://drmcninja.com/archives/comic/3p1/)

Got there first, though your link is better, as it's the start of the story arc, mine is just before the jet-pack reveal!

[Ravens_cry]

My brain is still broken about the "ion cannon powered by blood plasma."
That's just ten kinds of ridiculous.
As for ideas, this is basically a pump (http://www.youtube.com/watch?v=0snTqLQLpBA). The human body uses organic pumps, we call it "the heart" and "the lungs and diaphragm", so it is not to hard to imagine an organic version of that that pumps air really fast out the back of it. You are going to need two synchronized sets of pumps unless you want the jet to pulse like, well, a pulse jet, and how it gets the energy is a pretty huge issue, but in theory anyway it could work.
Now, never ever get blood plasma the bodily fluid and plasma the fourth state of matter confused again, please.

[Krüsher]

My brain is still broken about the "ion cannon powered by blood plasma."
That's just ten kinds of ridiculous.
As for ideas, this is basically a pump (http://www.youtube.com/watch?v=0snTqLQLpBA). The human body uses organic pumps, we call it "the heart" and "the lungs and diaphragm", so it is not to hard to imagine an organic version of that that pumps air really fast out the back of it. You are going to need two synchronized sets of pumps unless you want the jet to pulse like, well, a pulse jet, and how it gets the energy is a pretty huge issue, but in theory anyway it could work.
Now, never ever get blood plasma the bodily fluid and plasma the fourth state of matter confused again, please.

Ya... My friend told me about that and my response was about the same as yours, and don't even get me started on how he even planned to shoot the ions.

[Krüsher]

Also thank you for the Dr. Mcninja references! I completely forgot that they had that! Although I never really understood why his jetpack worked except... Hamburgers, lots and lots of hamburgers.

[Ravens_cry]

Ya... My friend told me about that and my response was about the same as yours, and don't even get me started on how he even planned to shoot the ions.
I am glad I wasn't the only one.

[golentan]

My suggestion? He has glands which excrete and store reactive chemicals in a manner similar to those of a bombardier beetle. When released into the "jet chamber" with air these combust and generate sufficient heat and pressure to provide lift. The valves reopen, flushing the used fuel and taking in new air, and the process repeats.

Mind you, this requires very different physical tolerances and capabilities from those of terrestrial life, especially if any sort of sustained flight is to be attempted. But hey, why not?

[Ravens_cry]

So in other words, a biological pulse jet (http://en.wikipedia.org/wiki/Pulse_jet_engine).

[golentan]

*shrugs* Pretty much.

[The Succubus]

My brain is still broken about the "ion cannon powered by blood plasma.".

O.O

I finally know what I want for my birthday in 2 weeks time. A death ray powered by the blood of shrieking victims? It's everything a demonic fiend could wish for. <3

[Asta Kask]

Some sea animals use jet propulsion.

[drakir_nosslin]

I think that if you want this to work in an environment with normal gravity you can't really use muscles to power the whole thing, you pretty much have to go chemical.

I guess you could deconstruct a dragon and reuse the ideas that people have come up with for them.

First, give the creature some kind of air-sacks that it fills with some kind of light gas, making it lighter and providing fuel. Then, you need some other chemical, stored in another sack that burns violently when combined with the above mentioned gas, I'm no chemists, but I'm sure there are a few combinations that can be used.

So, this creature fills up both sacks through filtering of food and some internal chem-labs. Then, when it's light enough, the creature pushes out the gases by compressing the sacks with a muscle similar to the diaphragm. As they combine the mixture burns violently, providing propulsion. The combining and burning might take place in some kind of cone-like bone structure, increasing the speed with which the burning fluid is ejected.

The creature itself needs to be very light, and probably aerodynamic. Possibly like a bird, hollow bones, feathers etc, but with small wings that are only useful for gliding when it runs out of fuel. It would probably only be able to fly for short bursts, but with very high speeds at those moments.

[Ravens_cry]

What you are thinking of is a hypergolic reaction. A lot of rockets use them because they don't need complicated ignition systems that can go wrong and are stable at room temperature, unlike cryogenic fuels. The bad news is they are some of the most nasty chemicals out there, like red fuming nitric acid, which is highly exothermic in water so likely out for meat based organisms. You also need a way of damping the heat from firing the rocket, the chemical reactions that allow meat to be alive are quite temperature sensitive, and also need something to prevent the nozzle from burning or melting.
Fire and meat just doesn't mix except in cookery.

[Traab]

Just as a note, while it might seem unlikely to create a pulse jet effect, they are animals that can repeat movements in rapid succession. A hummingbird for example, can beat its wings 12–90 times per second. So a biological pump capable of creating a sufficient amount of thrust rapidly isnt that impossible to comprehend. I cant say how it could work best, just pointing out that a pulse style of flight could be biologically possible. I mean, if a bird can flex that assortment of muscles that quickly, why not?

[drakir_nosslin]

What you are thinking of is a hypergolic reaction. A lot of rockets use them because they don't need complicated ignition systems that can go wrong and are stable at room temperature, unlike cryogenic fuels. The bad news is they are some of the most nasty chemicals out there, like red fuming nitric acid, which is highly exothermic in water so likely out for meat based organisms. You also need a way of damping the heat from firing the rocket, the chemical reactions that allow meat to be alive are quite temperature sensitive, and also need something to prevent the nozzle from burning or melting.
Fire and meat just doesn't mix except in cookery.

Well, the combining and ejecting parts would be made out of bone, but that might not be hard enough. Besides, there would have to be muscles somewhere to open and close the valves and push the fluid out. I guess that rules out that option then...


Just as a note, while it might seem unlikely to create a pulse jet effect, they are animals that can repeat movements in rapid succession. A hummingbird for example, can beat its wings 12–90 times per second. So a biological pump capable of creating a sufficient amount of thrust rapidly isnt that impossible to comprehend. I cant say how it could work best, just pointing out that a pulse style of flight could be biologically possible. I mean, if a bird can flex that assortment of muscles that quickly, why not?

I'm no physicist, but I suspect that that muscle power required to lift a creature with functioning wings is significantly less compared to that needed to lift someone up by pumping air at high speeds through the body.

[H Birchgrove]

What you are thinking of is a hypergolic reaction. A lot of rockets use them because they don't need complicated ignition systems that can go wrong and are stable at room temperature, unlike cryogenic fuels. The bad news is they are some of the most nasty chemicals out there, like red fuming nitric acid, which is highly exothermic in water so likely out for meat based organisms. You also need a way of damping the heat from firing the rocket, the chemical reactions that allow meat to be alive are quite temperature sensitive, and also need something to prevent the nozzle from burning or melting.
Fire and meat just doesn't mix except in cookery.

That stuff is nasty... As found out by Luftwaffe pilots and mechanics:

Messerschmitt Me 163 Komet (http://en.wikipedia.org/wiki/Messerschmitt_Me_163)

[Ravens_cry]

That stuff is nasty... As found out by Luftwaffe pilots and mechanics:

Messerschmitt Me 163 Komet (http://en.wikipedia.org/wiki/Messerschmitt_Me_163)
Yes, I know, I had a keen interest in German experimental aircraft growing up.
Still do.
The idea of being dissolved by acid alive is one of my own particular nightmare fuels, no pun intended.
Yes, this freaks me out so much, I, notorious punster, do not intend a pun.