Exploring the N-Prize Problem with a Space Hose Solution

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In summary, the Space Hose is a new concept for a low cost Space Tower that uses a lightweight hose made from PE foil and the frictional forces of flowing air to produce continuous lift. Originally designed as an alternative approach to the N-prize problem, it was found that a 100km hose could potentially be supported within the N-prize budget and weight limit. However, there are stability and technical challenges to overcome, such as keeping the tower upright for 9 days in a geostationary orbit. The proposal also includes calculations for using a de Laval nozzle to achieve orbital speed, but this is considered unrealistic for the current structure. Overall, the Space Hose is an original idea worth considering, but further improvements and calculations are needed
  • #141
DaveC426913 said:
Cool. I'd be interested in your first take on fan speed/pressure.

Well, the first key finding was that actually the blow speed at the bottom is lower (which is logic if you limit the head to 270m/sec which is approximately the speed of sound at -90 degree of Celsius), but you need a slightly higher surpressure to keep the whole thing stable (approximately 500-1000 Pa). This helped a lot to sort out the do I feed flow speed or surpressure at the bottom question which I never could sort out when I tried to calculate from there (predicting these 2 variables at the top is much easier and logically).

Funny is that the top contributes most of the pull forces even without the diffusor, which is good for extra stability. I already assumed this (because of the v² of the friction forces, but I didn't have any idea to what extent)

I'll see if I can warp it up and add some comments and colors for the changabel fields until this evening than you can play with it yourself.

Having such a 'virtual Space Hose' where all the parameters are changeable is pretty funny, and it even gives interesting results like pressure waves on top if the surpressure is too low, or how low you can bring the hose tensions down before it fails to stay errect (approximately 100N/mm² - which is not so far away from plain PE)

As I already mentioned I'm doing also some open source software development as another hobby so as soon as I found the formulas on how to calculate the Standard Atmosphere model from the definitions it was not so diffucult to build a Spreadsheet out of it.

http://www.pdas.com/coesa.ht [Broken]

Then I found another Webpage where you can calculate air viscosity for all temperatures:

http://www.lmnoeng.com/Flow/GasViscosity.htm

It took me almost 1 hour to get all 100 viscosities for the model, but I was too lazy to try to reverse engineer the math for this too :-)

From these two raw inputs you have everything needed for the pressure loss calculation at all heights, and then the fun started when putting it together.

gutemine
 
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  • #142
One more question on the wind - I found a nice picture on this (see attachment)

Would this mean that a hose with pull from top would actually form more or less such a bent curve ?

Because I would like to include also the pull force calculation into the excel, and for this I need a better understanding of the distribution of the wind force on the lower end of the hose.

gutemine
 

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  • #143
Damned - I still have problems with my Excel and the discrete calculation steps because now I have a circular reference.

If I go 1km down this means that the pressure on the bottom should be the one at the top + pressure loss from friction + hydrostatic pressure of the 1km of gas.

The problem is that hydrostatic pressure is dependant on the density, which is resulting from the pressure from bottom to top (if I asume that temperature is always aproximately outside temperature of the standard atmosphere) = circular reference. Now I understand why the books are saying this is a differetial equation with an integral which is only numericially solveable - if at all :-(

And if I try to overcome this by simply taking the previous density as I did until now the result is underestimating pressure, which makes the numbers look good, but then the model is invalid beyond the top few kilometers of the hose, because only there density and hence hydrostatic pressure is low enough to allow such a simplification. So calculating top to bottom was a good idea, but gives wrong results at the bottom because of the discretisation. This is also the reason why going from bottom to top produced too high numbers on top.

But problems are there to be solved, and input is welcome ;-)

gutemine
 
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  • #144
Is the "space hose" thread over?
 
<h2>1. What is the N-Prize Problem?</h2><p>The N-Prize Problem is a challenge created by physicist Paul Dear to send a spacecraft weighing no more than 9.99 grams into orbit on a budget of £999. The goal is to encourage innovative and cost-effective solutions to space exploration.</p><h2>2. What is the Space Hose Solution?</h2><p>The Space Hose Solution is a proposed method for achieving the N-Prize by using a long, thin hose to transfer momentum and propel a spacecraft into orbit. This idea was first proposed by mathematician and computer scientist John Walker.</p><h2>3. How does the Space Hose Solution work?</h2><p>The Space Hose Solution involves launching a long, thin hose from the Earth's surface into space. The hose is then filled with a fluid, such as water or gas, and accelerated to high speeds using a motor or other propulsion system. This creates a momentum transfer between the Earth and the hose, propelling the spacecraft attached to the end of the hose into orbit.</p><h2>4. What are the potential benefits of the Space Hose Solution?</h2><p>The Space Hose Solution has the potential to greatly reduce the cost and complexity of space exploration. It could also open up opportunities for smaller organizations and individuals to participate in space missions. Additionally, the technology used in the Space Hose Solution could have other applications, such as launching satellites or cleaning up space debris.</p><h2>5. What are the challenges and limitations of the Space Hose Solution?</h2><p>One of the main challenges of the Space Hose Solution is the engineering and technical difficulties involved in launching and controlling a long, thin hose in space. There are also concerns about the stability and safety of the hose and the potential environmental impacts of using a fluid as a propellant. Additionally, the Space Hose Solution may not be suitable for all types of space missions and may not be able to achieve the same level of precision and control as traditional rocket launches.</p>

1. What is the N-Prize Problem?

The N-Prize Problem is a challenge created by physicist Paul Dear to send a spacecraft weighing no more than 9.99 grams into orbit on a budget of £999. The goal is to encourage innovative and cost-effective solutions to space exploration.

2. What is the Space Hose Solution?

The Space Hose Solution is a proposed method for achieving the N-Prize by using a long, thin hose to transfer momentum and propel a spacecraft into orbit. This idea was first proposed by mathematician and computer scientist John Walker.

3. How does the Space Hose Solution work?

The Space Hose Solution involves launching a long, thin hose from the Earth's surface into space. The hose is then filled with a fluid, such as water or gas, and accelerated to high speeds using a motor or other propulsion system. This creates a momentum transfer between the Earth and the hose, propelling the spacecraft attached to the end of the hose into orbit.

4. What are the potential benefits of the Space Hose Solution?

The Space Hose Solution has the potential to greatly reduce the cost and complexity of space exploration. It could also open up opportunities for smaller organizations and individuals to participate in space missions. Additionally, the technology used in the Space Hose Solution could have other applications, such as launching satellites or cleaning up space debris.

5. What are the challenges and limitations of the Space Hose Solution?

One of the main challenges of the Space Hose Solution is the engineering and technical difficulties involved in launching and controlling a long, thin hose in space. There are also concerns about the stability and safety of the hose and the potential environmental impacts of using a fluid as a propellant. Additionally, the Space Hose Solution may not be suitable for all types of space missions and may not be able to achieve the same level of precision and control as traditional rocket launches.

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