A vacuum airship is an airship of a rigid construction, inside the shell of which a technical vacuum of a given depth is created and maintained (evacuation), as a result of which, in accordance with the Archimedes law, aerostatic lifting force will arise as the difference between the Archimedes force and the weight of the apparatus as a whole.
In 1670 , the Jesuit 16 ] - 1687 ) [2] [3] published the book "Prodromo, ouero faggio di alcune inuentioni nuoue premeffo all'arte maestra" Great Art ”), in the 6th chapter of which he described a ship with a mast and a sail on it. This vessel, according to Lana, could fly, supported by four pre-evacuated copper spheres with a diameter of about 7.5 meters each and with a copper wall thickness of about 0.1 [4] mm. Francesco Lana believed that such an aircraft could be lighter than air. In a reissue of his work in 1686, Lana indicated that the weight of a copper empty sphere would become comparable to the weight of displaced air with its diameter of 130 feet (about 40 m) and a wall thickness of about 1.5 mm, which of course was technologically impossible in his time. He also calculated the spheres (capable of lifting the load to several kilograms): glass (with a diameter of about 1.2 m with a wall thickness of about 0.15 mm) and wooden (with a diameter of about 3 m with a wall thickness of about 1 mm) [5] [ 6] .
The idea of Lana, outstanding for its time, was based on clear principles, but was not implemented in the experiment (which was also typical of 17th century science). Already Giovanni Borelli indicated that the spheres would be too thin to withstand external air pressure. Lana knew that the external pressure on the empty ball would be great, but thought it wasn’t dangerous for his design.
Nevertheless, the idea was popular and was often depicted in engravings with illustrations of a fantastic journey to Mars (1744) up to the first flights in hot air balloons (1783) or hydrogen, where the atmospheric pressure on the shell of the device was compensated by the pressure of the gas filling this shell. After their appearance, the idea of Lahn was forgotten for a long time. [7] [8] However, the operation of gas balloons (and subsequently airships) revealed a number of serious shortcomings of them (see the article "Airship" ).
Only in 1830, Hyacintho Amati in his book Ricerche storico - critico - scientifiche sulle origini ... paid Lana credit as a pioneer of aerostatics.
In 1887, Arthur De Bausset published a book [9] and tried to get money to create a cylindrical vacuum airship [10] by organizing the Transcontinental Aerial Navigation Company of Chicago . [11] [12] However, his patent proposal was rejected. [13]
In 1974, the London Patent Office published application No. 1345288 MKI B64B 1/58 Pedrick AP "Improvement of aircraft provided by evacuated balloons or other deflated vessels." The invention lies in the fact that the shell of the ball must be double. Air is pumped out of the inner sphere, and gas is pumped into the cavity between the inner and outer spheres under pressure (hydrogen or helium will come off). According to the inventor, this gas must maintain a given shape of the shell from being squeezed by its atmosphere (de Bosset is the priority of this idea). Both spheres in many places are fastened together.
However, it did not come to the practical implementation of this invention (due to the insufficient strength of the material of modern shells) and to this day there is no information about the widespread use of this invention.
Content
Physical principles and limitations
The theory of strength of a spherical thin-walled evacuated shell (in statics ) was developed by Swiss R. Zoelli in 1915. Combining his strength equation with the condition of buoyancy in the atmosphere, the condition for the practical implementation of the Lana spheres is obtained: [14]
- ,
Where - a certain set of strength indicators of the material of the sphere ("Lahn coefficient"), and - a physical indicator of the properties of the atmosphere in the flight zone (“atmospheric Lana number”), which can be calculated by knowing either the density and pressure of the gas, or its pressure, temperature and molecular weight. Celli determined that the wall thickness of Lana's balls should be proportional to the first degree of their radius. According to the Celle formula, the Lana spheres (even the perfect spherical shape) would crumble in the Earth’s atmosphere even when only ~ 0.1% of air was pumped out of them. To ensure the integrity of the evacuated Lana spheres under the pressure of the Earth’s atmosphere (even using modern structural materials), their wall thickness would have to be increased, which would lead to a violation of the above conditions for practical implementation. The ball of Lana should have sufficient strength and rigidity so that atmospheric pressure does not crush it, and have a sufficiently small weight (mass) of the structure to take off due to aerostatic lifting force, which is currently not possible in the Earth’s atmosphere ..
In connection with the foregoing, in 1993 in Russia developed and patented an invention for a device for creating the lifting force of a vacuum airship, where it was proposed to use dynamic compensation of atmospheric pressure to facilitate its shell. [15] . The theoretical part of the invention has been published [16] . The results of these studies inspire optimism regarding the possibility of creating a flight model of a vacuum airship. Currently, there are no published and patented data on the further development of the ideas embodied in this invention.
Apparatuses for shell evacuation method
Given the equation of state of an ideal gas and the Archimedes law, airships with evacuated shells can differ in the way the shell is evacuated:
- pumping out atmospheric air from a constant-volume shell by a turbocompressor (vacuum pump ) or a vacuum compressor ;
- an increase in the volume of the shell without simultaneously increasing its mass and the ingress of air or other gas into it from outside.
The aerostatic lifting force during the first method of evacuation in flight can be controlled by inlet into the shell or by pumping out a portion of atmospheric air from its shell [17] .
When using the second method of evacuation to control the magnitude of the lifting force, it is sufficient to change the amount of evacuated
shell . However, the application of the second method is currently limited by the strength of the material of modern shells.
This section provides a photo of the bench model of a vacuum airship according to the first method of evacuation, made and tested by the author of the above Russian invention No. 2001831 from 10.30.1993. For the lateral surface of the shell of the model, the author applied sheet rubber.
Links
1. Hall, Loura . Evacuated Airship for Mars Missions (English) , NASA (April 4, 2017). Date of treatment November 7, 2017.
2. Ahmeteli A.M. Gavrilin A.V. "Layered Vacuum Balloon Shells," US Patent Application 11 / 517915. Published February 23, 2006.
Notes
- ↑ John David Anderson. A History of Aerodynamics: And Its Impact on Flying Machines. - Cambridge University Press, 1997. - S. 80-81. - 478 p. - ISBN 0521669553 .
- ↑ Francesco Lana-Terzi, SJ (1631–1687); The Father of Aeronautics . Date of treatment November 13, 2009.
- ↑ The Life of Francesco Terzi de Lana . Date of treatment November 2, 2016.
- ↑ Clive Catterall. The Hot Air Balloon Book: Build and Launch Kongming Lanterns, Solar Tetroons, and More. - Chicago Review Press, 2013 .-- ISBN 1613740964 .
- ↑ Evg. Shikhovtsev. The flying ship Francesco Lana through three and a half centuries (2016). Date of treatment June 18, 2016.
- ↑ Francesco Lana Terzi. Magisterii natvrae et artis, Tomvs II. - Mariam Ricciardvm, 1686. - T. 2. - S. 291-294.
- ↑ New Scientist , Farmer Buckley's Exploding Trousers: & other events on the way to scientific discovery , Hachette UK, 2016, ISBN 1473642760
- ↑ MythBusters: Can a lead ball fly? New Scientist 2725 (2009)
- ↑ De Bausset, Arthur. Aerial Navigation . - Chicago: Fergus Printing Co., 1887.
- ↑ Scamehorn, Howard Lee. Balloons to Jets: A Century of Aeronautics in Illinois, 1855–1955. - SIU Press, 2000. - P. 13-14. - ISBN 978-0-8093-2336-4 .
- ↑ Aerial Navigation // New York Times : newspaper. - 1887. - February 14.
- ↑ To Navigate the Air // New York Times : newspaper. - 1887. - February 19.
- ↑ Mitchell (Commissioner). Decisions of the Commissioner of Patents for the Year 1890. - US Government Printing Office, 1891. - P. 46. - "50 OG, 1766."
- ↑ Evg. Shikhovtsev. Is a Lanolet possible? (2016). Date of treatment November 2, 2016.
- ↑ "Device for creating the lifting force of aircraft lighter than air", Russian patent RU No. 2001831 B64B 1/58, B64B 1/62 , registered in the State register of inventions on October 30, 1993. Author Malyshkin A.I.
- ↑ Malyshkin A.I. Vacuum airships (LA) (2015).
- ↑ Stromberg A.G., Semchenko D.P. Physical Chemistry: Textbook. for chem. specialist. Universities / Ed. A. G. Stromberg. - 7th ed. - M.: Higher School, 2009 .-- 527 p. - ISBN 978-5-06-006161-1 .