Error by ODEs solution

#21 Posted: 12/18/2023 1:34:40 PM

Valery Ochkov

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Thanks, Alvaro!
My email OchkovVF@mpei.ru

Alvaro!
I am waiting for your email!
Send me one letter!

#22 Posted: 12/18/2023 1:42:28 PM

Valery Ochkov

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3 stages variation.

Checking with Tsiolkovsky rocket equation in a gravitational field with several stages
Alvaro.

There is such a Meshchersky equation. In the West it is called differently.

Уравнение Мещерского

В отношении И.В. Мещерского память потомков совершила вопиющую несправедливость. Дифференциальное уравнение движения тела переменной массы, которое И.В. Мещерский вывел и опубликовал ещё в 1897 году, спустя 31 год (!) было (по незнанию трудов Мещерского) заново выведено итальянским математиком Туллио Леви-Чивита. К сожалению, как это уже не раз бывало, о русском первооткрывателе на Западе забыли, и это уравнение стали называть "уравнением Леви-Чивита". (https://borisgen.livejournal.com/22811.html)

#23 Posted: 12/19/2023 3:30:51 PM

Valery Ochkov

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New versions
Polet na Lunu.docx (496 KiB) downloaded 19 time(s).
Rakete-1.sm (17 KiB) downloaded 31 time(s).
Rakete-2.sm (17 KiB) downloaded 27 time(s).

#24 Posted: 12/22/2023 1:21:28 PM

Valery Ochkov

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Group: User

Wrote
New versions
Polet na Lunu.docx (496 KiB) downloaded 19 time(s).
Rakete-1.sm (17 KiB) downloaded 31 time(s).
Rakete-2.sm (17 KiB) downloaded 27 time(s).

#25 Posted: 12/22/2023 1:24:37 PM

Valery Ochkov

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Old good Euler. With units.

Rakete-2-RK-E.sm (27 KiB) downloaded 24 time(s).

1 users liked this post

Martin Kraska 12/23/2023 1:11:00 AM

#26 Posted: 12/23/2023 1:11:01 AM

Martin Kraska

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Three examples: the napkin calculation of "Nine Days of One Year", a single-stage and a two-stage rocket with parameters such that humans could survive the flight (limited acceleration).
The first section of the pdf is based on Valery's text posted earlier. It also includes some tasks for the reader.

Rakete.sm (23 KiB) downloaded 25 time(s).
Rakete2.sm (24 KiB) downloaded 27 time(s).
Serviette.sm (9 KiB) downloaded 32 time(s).
Rocket.pdf (421 KiB) downloaded 27 time(s).

Martin Kraska Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx

#27 Posted: 12/23/2023 4:46:41 AM

Valery Ochkov

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#28 Posted: 12/23/2023 6:16:12 AM

Martin Kraska

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Whether m(t) is P or P+m[2 after engine cut-off depends on whether you get rid of the structure of the second stage or not. As long as we don't consider any subsequent maneuvers, the difference has no influence. If you do nothing, then payload and empty second stage will orbit side by side, separated or not.

Martin Kraska Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx

#29 Posted: 12/23/2023 3:03:09 PM

Valery Ochkov

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Whether m(t) is P or P+m[2 after engine cut-off depends on whether you get rid of the structure of the second stage or not. As long as we don't consider any subsequent maneuvers, the difference has no influence. If you do nothing, then payload and empty second stage will orbit side by side, separated or not.

In Russia we say - punctual as a German!

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