Introduction

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derrick
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Re: Introduction

Postby derrick » Tue Nov 07, 2017 3:10 pm

It'll probably have to be multiple pieces, since there's no real flat surface.

I don't think that it should necessarily be a design consideration in blender that it will be 3D printed, we can break up the model afterwards.

There are 3D printer types that would be able to print it with less regard to the shape too, such as "powder bed" ( https://en.wikipedia.org/wiki/Powder_be ... D_printing )
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cameron
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Re: Introduction

Postby cameron » Wed Nov 08, 2017 5:10 pm

Ernest Hancock wrote:
Tue Nov 07, 2017 3:06 pm
I have a request. We need to know the air displacement of the shell. This volume will determine how much it will lift. We'll need to measure the helium/hydrogen air bag volume needed to lift the craft without thrust if possible. The airfoil still needs to be maintained so that capacity is increased with forward thrust/lift.
Hi Ernie. I'm still listening to yesterday's archive. I'm glad you like it.

For cubic volume, I used the main "body" (without the movable wings, engines, "skull", or the tail).
p13.jpg
p13.jpg (9.06 KiB) Viewed 218 times
At its current size, it calculates to 39,309,656 cu.ft. If you chop off the wings (fuselage only), it drops to 23,256,222 cu.ft.

Do airfoil's work at that scale? The wings are over 600' long. I'm not an engineer, but imagine you'd need extreme air flow to get lift from something that large.

I'm sure I'll be too nervous to be useful on the show. I'm very quiet (100% introvert). I'm the complete opposite of you on your show. But if you like, we can try an aftershow, or something where I don't have to worry about sounding horrible.

Thanks.
Ernest Hancock
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Re: Introduction

Postby Ernest Hancock » Sat Nov 11, 2017 1:32 am

https://www.google.com/search?q=lockhee ... 20&bih=987

If it moves it'll provide lift.

Thanks for the calc.

Aftershow, or just a podcast on Monday or even before with the guys while they are here.

The rear of the ship has rocket engines (hard to see in the schematic.

After 10 uses the SpaceX rockets (Merlin and the Raptor engines) go on the used market :)
Ernest Hancock
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Re: Introduction

Postby Ernest Hancock » Sat Nov 11, 2017 1:48 am

Donna Hancock, Producer <producer@DeclareYourIndependenceWithErnestHancock.com>

Please email Donna with your contact info so we can get you on. It'll be fun.

Donna - 602 828 1819
Ernest Hancock
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Re: Introduction

Postby Ernest Hancock » Sat Nov 11, 2017 1:54 am

Question
What is the weight of 1 cubic foot of air?
Asked by: Jonathan

Answer
FINAL ANSWER: 1 cubic foot of air at standard temperature and pressure assuming average composition weighs approximately 0.0807 lbs.
Ernest Hancock
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Re: Introduction

Postby Ernest Hancock » Sat Nov 11, 2017 2:26 am

Helium is less dense than air. Helium has 0.0114 pounds per cubic foot

Hydrogen lifts 68 lbs per 1,000 cubic feet [1], thus ~14.71 cu. ft. per lb

The weight of standard air is 1.2256 Kg/ Cubic Meter.
The weight of hydrogen is 0.0857 Kg/ Cubic Meter. = https://www.unitjuggler.com/convert-vol ... to-m3.html =
Conversion base : 1 ft3 = 0.028316846592 m3 Conversion base : 1 m3 = 35.314666721489 ft3

.0857x.028316846592=0.002426754
Sooo I guess
Hydrogen is 0.002426754 per cubic foot (I'd check this. that's a lot lighter than Helium.

Hydrogen would be an interesting choice since the solar panels can crack water into Hydrogen that can be stored for rocket fuel, along with the Oxygen, and for the bags.

Maybe not "with" the oxygen :)

If you do some of this calculations with as much space as you can use for bags then we'll know what thrust/lift we need and how much weight in material we will get to use

Such as:
23,256,222 cu.ft of the trimmed down ship may need 2/3rds of the space for cargo and people space etc.
So say 8,000,000 Cu.ft. that's
645600 lbs. of air that will be replaced with
19414 lbs of Hydrogen or
91200 lbs of Helium

So that means that we get to use 626186 lbs of structure to make the craft float without any lift or thrust..... interesting.

This is "Napkin Math" and I'd check it. But it gives you an idea. It also explains why you need to have as much air displacement as possible and still keep a lifting shape. But coolness is a factor as well. I like your work.

When you get further along and are able to place where the bags will go then we can start working on the gas vs. open spaces and what thrust we need for Vertical takeoff. Then the aerodynamics of the wing for its lift at what seeds... blah blah blah.

Your work on the displacement just got us a lot further along. Thank you!

After you have time to play with this then we can do some math.

If you ever check these numbers and are comfortable putting together some illustrations with these facts, let me know and we'll put something together for the forum OR you can just start posting these calcs up now and get more people helping with such stuff.

Peace,
Ernie
Ernest Hancock
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Re: Introduction

Postby Ernest Hancock » Sat Nov 11, 2017 2:37 am

This suggests that the calcs I did comparing Helium to Hydrogen were wrong, I hope you get the idea.

The Relative Lifting Ability of Hydrogen and Helium

Although helium weighs twice as much hydrogen, because each gas is so much lighter than air helium provides about 93% of hydrogen’s lift at full purity. In practical operation it is impossible to achieve or maintain 100% purity of either gas, reducing helium’s lifting ability to about 88% of the lift of hydrogen.

The actual lifting ability of each gas varies with temperature, pressure, and humidity, and to take account of varying atmospheric conditions and gas impurities airship designers often conservatively estimated helium’s lift at 60 lbs per 1,000 cubic feet and hydrogen’s lift at 68 lbs per 1,000 cubic feet.

Relative lifting ability of 100% Hydrogen vs. Helium
60° F, Barometric Pressure 29.92″ Hg

Weight of Lifting Gas
(per 1,000 cu. ft.) Weight of Air
(per 1,000 cu. ft.) Net Lift
(per 1,000 cu. ft.)
Hydrogen 5.31 lbs 76.36 lbs 71.05 lbs
Helium 10.54 lbs 76.36 lbs 65.82 lbs


The Effect of Helium on Airship Range and Payload

In actual use, because of physical realities and operational considerations, the use of helium can reduce an airship’s payload lift by almost half.
Ernest Hancock
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Re: Introduction

Postby Ernest Hancock » Sat Nov 11, 2017 2:38 am

Ernest Hancock
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Re: Introduction

Postby Ernest Hancock » Sat Nov 11, 2017 3:00 am

https://www.youtube.com/watch?v=7LKgtdNFi-g

Building light

Carbon Nanotube structure and graphene coating/hydrogen containment
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cameron
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Re: Introduction

Postby cameron » Sat Nov 11, 2017 3:19 pm

I was reading the same page a few days ago!

Found the same 68lbs/1000cu.ft. That means 1300 tons for the 39 million cu.ft. volume. Did you read the comments about recompressing helium instead of venting it? http://www.airships.net/helium-hydrogen ... ent-589500

I will email Donna today.

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