Bondsmith Flight

[Frustration he/him]

So Adhesion is the surge of pressure and vacuum. So make a vacuum in front of you and put pressure behind and boom, flight achieved.

[Quantus he/him]

24 minutes ago, Booknerd said:

So Adhesion is the surge of pressure and vacuum. So make a vacuum in front of you and put pressure behind and boom, flight achieved.

Well, Thrust at least... Steering might still be a challenge.  

[Frustration he/him]

Probably would need plate to breath to, steering wouldn't be too diffrent from lashings you would just need to adjust them. And you don't have to worry about such annoying things, like terminal velocity.

[Quantus he/him]

7 minutes ago, Booknerd said:

Probably would need plate to breath to, steering wouldn't be too diffrent from lashings you would just need to adjust them. And you don't have to worry about such annoying things, like terminal velocity.

I was more picturing it having similar issues to pulsed explosion drives.  Lashings give you a nice linear vector, this seems more along the lines of bouncing off a series of bubbles.  But I could be wrong on that, I suppose it depends on how much shaping detail they'd be able to pull off.

 

As an alternative design, all they need is some kind of air foil (they wouldnt even need real wing profiles) and they can apply basic vacuum to the top for traditional wing lift.  

[Frustration he/him]

2 hours ago, Quantus said:

I was more picturing it having similar issues to pulsed explosion drives.  Lashings give you a nice linear vector, this seems more along the lines of bouncing off a series of bubbles.  But I could be wrong on that, I suppose it depends on how much shaping detail they'd be able to pull off.

 

As an alternative design, all they need is some kind of air foil (they wouldnt even need real wing profiles) and they can apply basic vacuum to the top for traditional wing lift.  

good point.

[SwordNimiForPresident he/him]

I think the issue with this method is that in traditional forms of lift, it is the action of the high pressure air trying to fill the low pressure zone that creates the force. With surges, the vacuum or high pressure are sustained. The air doesn’t rush in or out, it is basically trapped as if it were in an air tank.

[Quantus he/him]

1 hour ago, SwordNimiForPresident said:

I think the issue with this method is that in traditional forms of lift, it is the action of the high pressure air trying to fill the low pressure zone that creates the force. With surges, the vacuum or high pressure are sustained. The air doesn’t rush in or out, it is basically trapped as if it were in an air tank.

That's only because in tradition wing aeronautics the forward motion is what is creating and driving the pressure difference, through an otherwise static geometry.  If you are magically creating the pressure difference directly then it will just be hanging from that bubble of low density, bypassing the need for the forward motion at all.  it would end up behaving more along the lines of a Dirigible or helium balloon.

[SwordNimiForPresident he/him]

3 minutes ago, Quantus said:

That's only because in tradition wing aeronautics the forward motion is what is creating and driving the pressure difference, through an otherwise static geometry.  If you are magically creating the pressure difference directly then it will just be hanging from that bubble of low density, bypassing the need for the forward motion at all.  it would end up behaving more along the lines of a Dirigible or helium balloon.

The geometry is how you create the pressure difference. It is the pressure difference trying to correct it’s self that actually creates the directional force. With surges the pressure is static and does not seek to equalize it’s self. It’s like putting and empty tank of air on top of a pressurized one. There is a pressure difference but no action to equalize it.

Dirigibles operate on bouyancy.

[Quantus he/him]

2 hours ago, SwordNimiForPresident said:

The geometry is how you create the pressure difference. It is the pressure difference trying to correct it’s self that actually creates the directional force. With surges the pressure is static and does not seek to equalize it’s self. It’s like putting and empty tank of air on top of a pressurized one. There is a pressure difference but no action to equalize it.

Dirigibles operate on bouyancy.

It’s not two separated rigid containers stacked near each other, more like a piston with two pockets and a separating surface that they push on.

Regardless, the underlying physics are all the same; they all rely on the same pressure/density differential mechanism to transmit the actual force, which is also the literal mechanism of buoyancy. They create it in varying ways, and how you describe it is more or less accurate for Wings specifically, but if you are able to manipulate the pressures directly you can bypass those mechanisms. 

Broadly speaking they are divided into AeroStats vs AeroDynes. Wings create the pressure difference using the geometry of the wing and the fact that the gas density is directly related to pressure, and pressure is directly related to Air velocity (ie Bernoulli's principle).  Dirigibles accomplish the difference with a gas that is innately less dense at standard atmospheric conditions; while hot air balloons do the same by heating a trapped volume of air.   In all cases they are utilizing various methods to create a relative pressure difference in the working fluid, which becomes the force acting on the foil, as the direct Force per Unit Area that is Pressure.  

 

EDIT: Sorry, my fluid dynamics professor had previously worked for Boeing, so he went straight to the aircraft examples whenever possible, and then go on and on way deeper than the example required (which I am often guilty of as well).  The only thing he liked more was explaining how the dimples on a golf ball actually manage to make the ball fly further.  

Edited February 13, 2020 by Quantus

[SwordNimiForPresident he/him]

1 hour ago, Quantus said:

It’s not two separated rigid containers stacked near each other, more like a piston with two pockets and a separating surface that they push on.

Regardless, the underlying physics are all the same; they all rely on the same pressure/density differential mechanism to transmit the actual force, which is also the literal mechanism of buoyancy. They create it in varying ways, and how you describe it is more or less accurate for Wings specifically, but if you are able to manipulate the pressures directly you can bypass those mechanisms. 

Broadly speaking they are divided into AeroStats vs AeroDynes. Wings create the pressure difference using the geometry of the wing and the fact that the gas density is directly related to pressure, and pressure is directly related to Air velocity (ie Bernoulli's principle).  Dirigibles accomplish the difference with a gas that is innately less dense at standard atmospheric conditions; while hot air balloons do the same by heating a trapped volume of air.   In all cases they are utilizing various methods to create a relative pressure difference in the working fluid, which becomes the force acting on the foil, as the direct Force per Unit Area that is Pressure.  

 

EDIT: Sorry, my fluid dynamics professor had previously worked for Boeing, so he went straight to the aircraft examples whenever possible, and then go on and on way deeper than the example required (which I am often guilty of as well).  The only thing he liked more was explaining how the dimples on a golf ball actually manage to make the ball fly further.  

I actually appreciate the thoroughness. I don't disagree with any of the science that you described.

I think I might be presenting my point in an unclear way. In all of the various forms of lift, the system works because it is able to interact with the atmosphere around it. The low pressure zone on top of a wing for example doesn't exist in a closed system, it is a localized low pressure area that the surrounding atmosphere will seek to find equilibrium with. It's that same on a larger scale with wind. High pressure areas interact with low pressure areas and create movement of air.

With the air pockets created by surges (either low or high density) there doesn't seem to be a flow of air. If there was a flow of air, it would need an inlet or outlet for excess gas, or it would eventually create a true vacuum or a singularity. If there is an outlet, then there would be no need to combine low & high pressure areas, as the outlet would generate thrust by its self.

[Quantus he/him]

4 minutes ago, SwordNimiForPresident said:

I actually appreciate the thoroughness. I don't disagree with any of the science that you described.

I think I might be presenting my point in an unclear way. In all of the various forms of lift, the system works because it is able to interact with the atmosphere around it. The low pressure zone on top of a wing for example doesn't exist in a closed system, it is a localized low pressure area that the surrounding atmosphere will seek to find equilibrium with. It's that same on a larger scale with wind. High pressure areas interact with low pressure areas and create movement of air.

With the air pockets created by surges (either low or high density) there doesn't seem to be a flow of air. If there was a flow of air, it would need an inlet or outlet for excess gas, or it would eventually create a true vacuum or a singularity. If there is an outlet, then there would be no need to combine low & high pressure areas, as the outlet would generate thrust by its self.

I think it depends on which example you are looking at.  When the surge is used specifically for Adhesion then I would agree with you, its all about preventing any volume from entering the Invested zone and thus "stick" with a maintained vacuum.  While that is a) the most common application of the surge (at least from a Radiant) and b) the reason I think the surge can be used to make "bottle" effects, Im looking to Kaladin's Parting of the Storm usage as indication that it doenst have to be a purely rigid container expression.   So long as at least one side can "float" even a little, the equalization forces should come into play and be able to Push on a surface. Which are literal Entropy forces, if we really want to chase the white rabbit...

[Karger he/him]

You could hover if you made some kind of hovercraft.  Steering would be slow and pretty dangerous since your entire method fails if you flip over which will always be possible.  Dalinar is totally going to try this at some point when learning that it is possible and will probably end up on his backside cursing to the Stormfather.

[Bigmikey357 he/him]

The application of this surge would be difficult for the in-world scholars to discover.  You guys have thrown enough aerodynamics lingo at me to believe in the possibility at least. It's like the Alcubierre drive only using air as the medium instead of space time, right?  The scholars have the math to make this theoretically possible but culturally they're going to find it difficult to overcome traditional trains of thought.  Windrunners and Skybreakers fly. They do so using Gravitation surge. They have a proven way in place,  one that needs no experimentation and is more widely understood. What would be the impetus for finding another way?

[Frustration he/him]

4 hours ago, Bigmikey357 said:

The application of this surge would be difficult for the in-world scholars to discover.  You guys have thrown enough aerodynamics lingo at me to believe in the possibility at least. It's like the Alcubierre drive only using air as the medium instead of space time, right?  The scholars have the math to make this theoretically possible but culturally they're going to find it difficult to overcome traditional trains of thought.  Windrunners and Skybreakers fly. They do so using Gravitation surge. They have a proven way in place,  one that needs no experimentation and is more widely understood. What would be the impetus for finding another way?

Hoid would tell Dalinar he could