Autogyro design pdf

[XXavier]

Searching the internet for information on a gyro-related topic (the inflow ratio), I've found a very interesting pdf on autogyro design, that can be freely downloaded:

https://www.researchgate.net/publication/301588181_Radio_controlled_autogiro_aerodynamic_design

After downloading the document, I searched the RWF and found a (2013) comment from kolibri282 praising this work, due to an Italian engineer (Bruno Zilli) who has also posted in this forum in the recent past.

The text is, in my opinion, not exactly elementary, but can be read and understood with some effort. As Plato wrote somewhere, 'beautiful things are difficult'...

 

[Resasi]

A more recent report than the Glasgow report, which had a great deal of influence on the CAA BCAR Section T, came out in 2014 as a Thesis by Sophie Robinson. It seems to have enlarged upon and increased knowledge on Gyroplane stability, as well as disagreeing with the Glasgow Reports findings on the effect of a tailplane, and suggesting the present B CAR T might possibly be overly restrictive.

https://livrepository.liverpool.ac.uk/2006919/1/RobinsonSop_Jul2014_2006919.pdf

With the increases in knowledge, computer speed and data handling capabilities, how close are we coming to being able to accurately model a particular Gyros design, and be able to predict its stability, handling qualities, and potential weaknesses before actually flying the machine itself?

There are within the Forum a number of members whose extensive knowledge I am sure would allow them to comment. @kolibri282

At present the lack of knowledge on stability and handling on single seat designs has seen a dwindling of new single seat types that could be more acceptable to the various countries that presently are wary of them and restrictively legislate in European countries, compared to the more open approach to EAB’s in the US. A shame because the more prolific two seaters tend to be more out of the common man’s economic reach.

 

[All_In]

Leigh that is brilliant.

We have a 3 axis flight simulator flying an ELA with a virtual headset.
Looked at the ELA's data as to how X-Plane could make it so realistic.
I was amazed at the depth of all the aerodynamic fields that could be changed and I understood how they created both a Bensen that does petal turns like a Bensen and ELA that behaves like an ELA.

They might want to inspect the data fields of X-Plane and if all the aerodynamic fields they would need/use are there.
Then it would be EASY The algorithms are already written to observe what happens when I change the prop pitch and or width.

 

[kolibri282]

/Quote: I searched the RWF and found a (2013) comment... /Quote

It has always troubled me to think about that huge wealth of information this forum could provide, how much slips into the background and how little it is used. We could easily incorporate some of the great instructive threads this forum has seen over the last years (decades) into the PRA database. I sincerely hope that many members will join the effort. Merging the TBP&P section into the PRA data base should only be a start. It would be great if the forum members could propose those incredibly informative threads to be incorporated into a "From the pilot to the pilot" recommendation that would allow the newbie to quickly find the advice from the RWF gurus and which we could set up in the PRA data base. Please join the effort and post your suggestions here.

 

[All_In]

Jergen is so right. The wealth of knowledge you all share could be categorized and added to PRA's library including all past magazines.
I'll be categorizing PRA's library.
Jergen is willing to input the Section, Subject, and tags into the database. We need your help with the threads Jergen has on his list.
A solution from now on? When you read a thread that you and put it on your thread list.
Post in the Section, Subject, and tags... And when I read that I post of yours. I'll add my suggestions and TAGS... Spelled incorrectly!!
And as I've told Tyger= Please correct my spelling and grammar.
It occurs to me that we could trick Tyger into helping. So don't tell Tyger or he may stop helping me.
Oops, did I say that out loud? HahahahahahahahaHehehehehehehehe
Request a little help from our friends?

 

[kolibri282]

Quote: Searching the internet for information on a gyro-related topic (the inflow ratio) /Quote
Inflow ratio, which is directly connected to rotor angle of attack, was discussed here, Javier:
https://www.rotaryforum.com/threads/gyroplane-teeter-rotor-systems.1145952/

The report naca-716, which is mentioned there, is available here:
https://ntrs.nasa.gov/citations/19930091794

How to calculate rotor AoA is explained a bit after formula 9 (for accelerating aerodynamic force) and formula 11 (for decelerating aerodynamic force) were presented on pages 5 and 6 (the pagination of the report says that page 6 is page 214). I have programmed formulae 9 and 11 to give a solution to the required inflow angle, so if you have a question regarding these I would probably be able to help you. Inflow ratio actually only depends on section lift and drag coefficients of the rotor, Lock number and the flight state which is uniquely determined by collective pitch and advance ratio (flight speed devided by rotor tip speed)

Cheers,

Juergen

 

[Kevin_Richey]

J
And as I've told Tyger= Please correct my spelling and grammar.

John: In another thread, you keep mentioning Corvid, instead of Covid.

Confusing to me, since spelling Covid w/ the "r" in it (CoRvid) refers to the family of smart black birds such as ravens & crows. I like both because they are very smart.

Fledglings crows do "crow hops" in their beginning-to-fly cycle. I have never witnessed ravens fledglings, since they appear to be in high country/very rural areas, whereas crows have adapted very well to city life w/ abundent food available for them to scavange.

I imagine ravens fledglings start by practicing hops also, something I strongly feel was very useful in flying a gyroplane. Getting in many series of take-offs & landings w/in a couple of feet off the runway in one pass down it greatly increases the learning experience vs. one takeoff, fly the pattern, & then do one landing, the traditional way taught for aircraft.

Jorhn, ardding arn rR irnto ervery wrord markes corn-fusing meranings!
But, I'm srue you get the mnaneig of eevn tihs sntecnee...

 

[All_In]

Confusing to me, since spelling Covid w/ the "r" in it (CoRvid) refers to the family of smart black birds such as ravens & crows. I like both because they are very smart.

Fledglings crows do "crow hops" in their beginning-to-fly cycle. I have never witnessed ravens fledglings, since they appear to be in high country/very rural areas, whereas crows have adapted very well to city life w/ abundent food available for them to scavange.

I imagine ravens fledglings start by practicing hops also, something I strongly feel was very useful in flying a gyroplane. Getting in many series of take-offs & landings w/in a couple of feet off the runway in one pass down it greatly increases the learning experience vs. one takeoff, fly the pattern, & then do one landing, the traditional way taught for aircraft.

Jorhn, ardding arn rR irnto ervery wrord markes corn-fusing meranings!
But, I'm srue you get the mnaneig of eevn tihs sntecnee...

I agree they may be the smartest bird.
Sorry about the spelling just proves I'm an idiot in print forever.

I cannot even notice there are any spelling errors in anything you wrote. That is the silver lining, I never act like a computer does not know what it says either. That the difference between humans and A.I. computers today. Humans can instantly know what the meaning is.

 

[Tyger]

Post in the Section, Subject, and tags... And when I read that I post of yours. I'll add my suggestions and TAGS... Spelled incorrectly!!
And as I've told Tyger= Please correct my spelling and grammar.
It occurs to me that we could trick Tyger into helping. So don't tell Tyger or he may stop helping me.
Oops, did I say that out loud? HahahahahahahahaHehehehehehehehe

John, I am happy to help within my competencies. I'm good at proofreading.
Database management? Not so much. 😛

 

[Tyger]

Confusing to me, since spelling Covid w/ the "r" in it (CoRvid) refers to the family of smart black birds such as ravens & crows. I like both because they are very smart..

I actually dislike the term "covid" as it's a sort of partial/composite acronym (COrono VIrus Disease), that now seems just a bit too glib for something so serious.

I have actually been writing "CorVi" (corona virus)* when discussing the virus itself, as opposed to its effects (the "D"isease). I believe scientists generally use the term SARS-CoV-2, for the disease/symptoms (SARS being a proper acronym for "severe acute respiratory syndrome").
E.g. https://www.cell.com/cell/fulltext/S0092-8674(21)00662-0?
(worth a read: "These findings demonstrate that not only neutralizing antibodies but also enhancing antibodies are produced during SARS-CoV-2 infection." I.e. some antibodies can actually make things worse, and more of these are found in patients who get severe symptoms)

* If memory serves, "corvi" can be either the (nominative) plural of "corvus" (so, "crows"), or genitive singular ("of a crow") in Latin.

 

[Brian Jackson]

I actually dislike the term "covid" as it's a sort of partial/composite acronym (COrono VIrus Disease), that now seems just a bit too glib for something so serious.

I have actually been writing "CorVi" (corona virus)* when discussing the virus itself, as opposed to its effects (the "D"isease). I believe scientists generally use the term SARS-CoV-2, for the disease/symptoms (SARS being a proper acronym for "severe acute respiratory syndrome").
E.g. https://www.cell.com/cell/fulltext/S0092-8674(21)00662-0?
(worth a read: "These findings demonstrate that not only neutralizing antibodies but also enhancing antibodies are produced during SARS-CoV-2 infection." I.e. some antibodies can actually make things worse, and more of these are found in patients who get severe symptoms)

* If memory serves, "corvi" can be either the (nominative) plural of "corvus" (so, "crows"), or genitive singular ("of a crow") in Latin.

This is why Tyler is awesome. I like that attention to detail.

 

[Tyger]

Thanks Brian!
Totally off topic (apologies) but since you are already reading this... 😇
I think some of the vaccine hesitancy we have seen stems from uncertainty about the kind of protection being given when stimulating antibody production through novel methods (mRNA). Some may have heard that vaccines for FIPV in cats (also a coronovirus) actually made things worse in the long term, "often sensitizing the cat through immune enhancement rather than providing protection."

Immunization against feline coronaviruses - PubMed

Feline infectious peritonitis (FIP) is caused by one of several strains of feline coronaviruses which are grouped into 2 general types of viruses. Infection of cats with FIP virus results in production of serum antibodies which may be protective in conjunction with cell mediated immunity, may...

pubmed.ncbi.nlm.nih.gov

The 2021 study published in Cell looked into, among other things, why that might have been the case:
"However, antibodies against viruses are not always protective (Bournazos et al., 2020). For example, antibodies against dengue virus protein can cause severe diseases mediated by the Fc receptor (Wang et al., 2017). In addition, feline infectious peritonitis coronavirus (FIPV) infection is exacerbated by vaccination of spike protein or adaptive transfer of the serum antibodies from FIPV-challenged animals (Vennema et al., 1990; Weiss and Scott, 1981), suggesting the presence of antibodies that augment coronavirus infection, although the exact mechanism of the enhancement of FIPV infection by such antibodies has remained unclear (Olsen, 1993). Therefore, understanding the function of antibodies produced during SARS-CoV-2 infection is quite important to elucidate the etiology of COVID-19."

(In case it makes a difference to anyone reading the above, I have had both CorVi (March 2020) and the J&J vaccine (August 2021)).

Now back to gyroplanes.
John, let me know how I can assist you!