Resizing solved, but...

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Bruno Ogorelec
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Resizing solved, but...

Post by Bruno Ogorelec » Tue Oct 28, 2003 4:06 pm

I have just realized that the Russian pulsejet book contains (among other highly interesting stuff) also a rough and ready method for pulsejet resizing -- a problem that has stymied the best minds of this forum for years.

The problem is that my Russian is good enough only to buy vodka in a Moscow store, handle the currency exchange and explain to professional ladies that I have other plans for the night. (I guess this reflects my travel agent background. People of other professions have probably developed fluency in other everyday tasks.)

The point is, this is not enough to translate technical stuff.

I would like to direct the Russian-speaking contingent towards that part of the book (it is somewhere between pages 48 and 52). Would you be so kind to find the method, translate the few sentences pertaining to the issue and reveal all to us non-Russkis?

I think this will be of tremendous interest to at least one forum participant out of two.

Bruno

sparks
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Post by sparks » Sun Feb 15, 2004 4:39 am

I just wanted to bring this subject up since this book is one of the things i just cant get out of my mind.
I dont understand a word or letter, but its obvious that it contains unvaluable information.

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Suck and blow manometer

Post by Mark » Mon Feb 16, 2004 3:52 am

If you look at page 26 of the Russian book, there is an interesting diagram. Just before any neck-down of the pulsejet, mounted above and below on the combustion chamber are two pneumatic pressure tubes. One it looks like has a tiny flap valve in the line, which only allows hot gases to escape and it leads to a U-shaped clear tubing which shows it is pushing the fluid in this U-tubing, causing to be pushed up to a higher level opposite the pressure side where the pneumatic line connects.
On the other tube mounted on the combustion chamber the tiny one-way flap valve in the other pneumatic line is reversed, this pneumatic line also leads to the other pressure indicator of sorts, a U-shaped tube again with fluid in it. But because the little reed in the little pneumatic line is reversed I think, the fluid in the U-shaped tube is higher where it is attached to the line, being drawn up from a vacuum created by the pulsejet on the reverse phase.
So you can either draw a vacuum it seems or conversely use the combustion chamber to push or pressurize something, both from essentially the same region of the puslejet chamber, to simplify, you could just reverse the valve in either line and get the opposite effect, a pushing force or a vacuum "pulling" force.
At least that's what the picture suggests to me, I don't read Russian.
I use to think the positive pressure phase would override any negative pressure, perhaps then a fuel could be introduced via a flap valve pneumatic line on the neck of the jet or somewhere else strategic, I don't know if fuel would move as fast as air molecules though before the next pressure wave hit?
For if you put a line with fuel level with the bottom of the combustion chamber it will quickly be pushed down the tube away from the jet. Could a one way reed overcome this effect?
As one who has been toying with a simple alcohol feed for a valveless, my tiny whiney Logan, this stuff interests me.
The Lockwood engine is pictured on one site where not even nuts or bolts or sand can be ingested, the momentum isn't fast enough for the massy objects to go in before the pressure is pushing back on an outflow phase.
I was looking at a kind of Gluhareff-like hybrid straight duct patent at my brother's today, it had the coils in the tail but unlike Gluhareff he had no sonic mixer triple stage gizmo, rather he had multiple propane injection points in the first half of the engine, which for the most part looked like a sleek typical turbo jet from the side. The thing claimed quite a bit of thrust, I will find out how much later, I only scanned it.
Then also I was looking at a several page article on the free piston guy, he only spent about 50,000 man hours developing it, the literature said!
Mark

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Re: Suck and blow manometer

Post by Bruno Ogorelec » Mon Feb 16, 2004 5:59 pm

Mark wrote:I was looking at a several page article on the free piston guy, he only spent about 50,000 man hours developing it, the literature said!
That's about 22 working years. About how much I spent chasing skirts before I gave up the sport and settled down. At least he has an engine to show for his trouble.

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Re: Suck and blow manometer

Post by Dmitry Petrov » Tue Feb 17, 2004 3:12 pm

Hi All !

I recently have seen this theme (this thread).
I shall try to answer questions soon (tomorrow).
I very badly understand your technical slang (sleng).

page 26 fig 12 = measurement max and min pressure in the combustion chamber (with help little valve), because in Russia in ~1960 it is not enough pressure_sensor (to answer the purpose).

Sorry for bad english.

WBR - Dima :)

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Post by Bruno Ogorelec » Tue Feb 17, 2004 3:28 pm

Dmitry,

Don't think about your English. It's good enough. Welcome to the forum.

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Post by Mike Everman » Tue Feb 17, 2004 3:31 pm

Hi, Dmitry.
Bruno, have you got this book in electronic format?
Mike
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Re: Suck and blow manometer

Post by Mark » Tue Feb 17, 2004 10:20 pm

Dmitry Petrov wrote:Hi All !

page 26 fig 12 = measurement max and min pressure in the combustion chamber (with help little valve), because in Russia in ~1960 it is not enough pressure_sensor (to answer the purpose).
Sorry for bad english.
WBR - Dima :)
Thanks for writing Dmitry and for looking at page 26 for me. If you can explain your sentence more, "because in Russia in ~1960 it is not enough pressure_sensor (to answer the purpose). Do they use the vacuum (min pressure) in some way for something? Were they getting enough max pressure to run a fuel pump or something?
Don't worry about your English, it's much better than my Russian!!!
Thanks,
Mark

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Post by Bruno Ogorelec » Tue Feb 17, 2004 11:30 pm

What Dmitry means, I think, is that the method you describe was used to measure pressure peaks and throughs. At the time, there were no pressure sensors to be had in Russia, so the measurements were made by barometric means.

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Post by Dmitry Petrov » Wed Feb 18, 2004 11:19 am

Hi Gentlemans !

This book named "Pulsejets for (flyings) airplane models" (i.e. exist (well-known's) pulsejets for exist (well-known's) models)
Author - V.A.Borodin [VJACHESLAV (name, his pet name - SLAVA - a kind of "glorify") ALEXANDROVICH (name of his father) BORODIN (family name)]
State Publishing House in Moscow - DOSAAF (this is acronym from "voluntary organization (society) for help (to assistance) army, aircraft (aviation), navy (fleet) (in USSR)" - this society do training (schooling, military training) young people (aged 14-18 y.) for army (including model aircraft construction, aircraft modelling) - vague similarity (conformity, kinship, resemblance) with society "Boy Scout's" (in USA))
publication data - 1968 y. from birth Jesus Christ (see page 2 (bottom), BUT basically this book writed at the end of the fifties y. (in the late fifties y.) - see last data an page 4 and my own knowledge (erudition))
Edition - 30 000 copies.
Price (cost) - 18 kopeck per copy (kopeck or copeck = bit (copper) money in USSR, correspond 1 copeck USSR in 1964 y. = 1 cent USA in 1964 y.)
Destination (purpose) this book - textbook (handbook, manual, guide) for model aircraft constructors (young constructors).

Abstracts
In this book achievements Soviet and foreign avia-model constructors on designing and operation (exploitation) of airmodelling pulsing air-breathing engines (PuVRD = pulsejet) and their installation (placing, setting) on flying models of planes are generalized (described). The significant attention is given analysis of a design of these engines and manufacturing techniques. Besides the elementary theory small-sized PuVRD is resulted and methods of definition of key parameters are stated. The book is designed for aviamodellers-sportsmans, instructors, heads of airmodelling groups and the broad audience of youth.

TABLE OF CONTENTS
Introduction...................................................................3
Chapter 1. A principle of action (operation) airmodelling PuVRD (i.e. pulsejet for model aircraft)...................5
Chapter 2. The elementary theory airmodelling PuVRD........................................................10
Chapter 3. Designs of elements (part, component) airmodelling PuVRD....................................................27
Chapter 4. Designs and a specification (engineering data) airmodelling PuVRD....................................................52
Chapter 5. Manufacturing airmodelling PuVRD........................................................61
Chapter 6. Operation (exploitation) airmodelling PuVRD.....................................................67
Chapter 7. Installation airmodelling PuVRD on flying models of planes......................................................72
Chapter 8. Airmodelling PuVRD and cord_jet models of foreign sportsmen.................................................90


Now about recalculations of sizes (for example for thrust augmentation).
V.A. Borodin suggests to increase proportionally the areas of sections (cross-section area), but to NOT change length and to NOT change rigidity (flexural rigidity) of valves (reed (?) valves (if valves corresponds camille-flower (shape)) - i don't understand this - "reed" = this is "metall flap" in bassoon or oboe?). It is fair for little changes - approximately in 0.75 - 2 times (scale factor).

Sorry for bad english.

WBR - Dima :)

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Post by Bruno Ogorelec » Wed Feb 18, 2004 1:58 pm

Dmitry Petrov wrote:i don't understand this - "reed" = this is "metall flap" in bassoon or oboe?).

Sorry for bad english.
Dmitry, you are wonderful. 'Reed' is indeed the little flap of elastic material that vibrates in the mouthpiece of a clarinet and similar musical instruments. Thank you for your effort!

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Post by Mike Everman » Wed Feb 18, 2004 2:03 pm

Wonderful Dmitry! Thank you!
Mike
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Post by Bruno Ogorelec » Wed Feb 18, 2004 2:05 pm

Oops, sorry, wrong thread.

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Post by Mark » Thu Feb 19, 2004 2:58 am

Dmitry Petrov wrote:Hi Gentlemans !

TABLE OF CONTENTS
Introduction...................................................................3
Chapter 1. A principle of action (operation) airmodelling PuVRD (i.e. pulsejet for model aircraft)...................5
Chapter 2. The elementary theory airmodelling PuVRD........................................................10
Chapter 3. Designs of elements (part, component) airmodelling PuVRD....................................................27
Chapter 4. Designs and a specification (engineering data) airmodelling PuVRD....................................................52
Chapter 5. Manufacturing airmodelling PuVRD........................................................61
Chapter 6. Operation (exploitation) airmodelling PuVRD.....................................................67
Chapter 7. Installation airmodelling PuVRD on flying models of planes......................................................72
Chapter 8. Airmodelling PuVRD and cord_jet models of foreign sportsmen.................................................90

Sorry for bad english.
WBR - Dima :)
Dmitry,
That is quite a bit of translating and it is very interesting to read what you have presented. Although your English isn't perfect, I can see quite a bit of insight/sensitivity in your writing, and it is a delight piece together just what you are saying, describing the reeds for example, "if valves corresponds camille-flower (shape)." It's great to have all of us, all around the world, share in such an interesting subject.
Most enjoyable,
Mark

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Post by cbromano » Thu Feb 19, 2004 3:11 am

I know of this website:

http://www.freetranslation.com/

It might help break the language barrier. It was enough to make me able to pass three years of spanish. I dont know how well it works between english and russian especialy with the more technical words but it might be worth the time to look at. They also have human translators that would be far more accurate, but it would cost money.

Chris Romano[/url]
I don't wish to know everything.
I just wish not to be ignorant.

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