Jin Eira and the others return to the laboratory and begin the review meeting.
The first thing they did was to unify the names.
"Recently, we've been doing a lot of joint research with the Aeronautics Laboratory," said Rusnar, the head of the laboratory.
Rasnath Heilbronn, the head of the laboratory, told Jin.
"First of all, ...... special guest, Jin-san, please point out anything you notice."
Jin opened his mouth, wondering if I was a special guest.
"Well, ...... first of all, kudos to you for the great idea."
A voice said, "Oh," and there was a round of applause from everyone.
"And in terms of weight reduction, the fact that it is a barrier using a magic circle instead of a magic tool is also a very good point.
"Oh, thank you. It was Katya who came up with the idea. I was thinking of using a magic tool.
"I see."
There was another round of applause, and Cachéa turned her head down in embarrassment.
"Next, I was wondering about something. ...... why do they hang the gondolas from the air sacs?
It seemed to me that if the wind was strong, the air sacs and the gondola would be affected separately, and the gondola in particular would sway and become unstable.
If they were attached directly to the air sacs, they would be more stable, Jin said.
"Then there's the material."
We need to consider weight reduction and strength, Jin concluded.
"Well, the gondola hanging from it is a prototype, so it should be ......."
Eira explains.
"As Jin said, we don't have to stick to the balloon format, after all, it's still in the experimental stage."
"That's right. Take a look at this."
Following Eira, Zora Himmel, Deputy Director of the Aeronautics Laboratory, showed us a rough sketch.
The sketches showed a cigar-shaped airship, four air sacs arranged in a square shape, and various other ideas.
Most of them had a cabin instead of a gondola ...... attached directly to the air sacs.
Let's assume that air weighs 1.2 grams per liter, so to lift a weight of 200 kilograms, we would need 167,000 liters of air sacs. 167,000 liters of air sac capacity would be required to lift a weight of 200 kilograms."
One liter is one thousandth of a cubic meter, so 16 This means that more than 167,000 cubic meters of air sacs would be needed to lift the 200 kg weight. Of course, the 200 kg weight includes the air sacs and the cabin.
As a side note, 167 cubic meters is a cube with a side of 5.5 meters.
As a side note, a typical 12-foot container for railroad use has a capacity of 18.7 cubic meters.
Another interesting fact is that the Hindenburg, which exploded and caught fire, had a maximum capacity of 200,000 cubic meters and a total deadweight of about 220 tons. The target was to carry a payload of 1 ton.
"The target is one ton of payload."
By our calculations, this would require a vacuum air sac with a capacity of 835 cubic meters.
This means that a that can float 1 ton is about the equivalent of 4.5 12-foot containers.
This value shows that the payload per capacity is a bit higher than the Hindenburg (Hindenburg is about 1.1 kg, <> is about 1.2 kg). .
"That size is practical, isn't it?"
"Yes, that's a reasonable goal for us."
The laboratory is only for development, and commercialization and mass production will be done by another department or an outside company.
"And what about the propulsion system when it is put to practical use?"
Jin was curious about this question, so he asked.
"I'm a little worried about that.
The answer was given by Mr. Lois Eisker, the head of the Aerospace Research Laboratory.
I would like to use jet thrusters, but they are too heavy.
"That's true."
Originally, Jin developed the jet thruster for marine use.
If they were to be used for balloons or airships, it is not surprising that their weight would be a problem.