Project Garuda an Introduction

[ColinB]

Welcome to my own little subsection for my aircraft,

 

Ill start with the name (From wiki) The Garuda (Sanskrit: Garuḍa गरुड, eagle; Pāli Garuḷa) is a large mythical bird or bird-like creature that appears in both Hindu and Buddhist mythology.

 

What it is, is an EZ based aircraft, i have compiled lots of information on the EZ and other canard aircraft and i will be constructing CAD models and subsequently machining patterns and creating molds from these, the aircraft will be constructed out of modern hi performance composite materials and processes (such as prepreg and modern core materials and autoclave use)

 

As i am in the UK, there will be some PFA (now called LAA) hoops to jump through, however i am not departing from the original design in any great way so this shouldnt be an issue

 

The initial specs of the aircraft will be

 

Retractable undercarriage

Mostly carbon construction

Engine choice at the moment is looking likely to be the Wilsch diesel (as the company is only an hour drive away from me) and there is already an ez flying with it and so approval shouldn't be a problem

 

Other additions i am looking at are a ballistic parachute and while not cheap, will give some peace of mind

 

one other project possibility i am considering is to release the CAD files as open source or some other similar license but ill need to have a think about the pro's and cons of that

[steve]

could you start with a water bound craft first ? i would love to build/buy a water landing cozy.

[Super-eze]

Colin,

 

I think you should open each phase for discussion before going to cad. The pros and cons of just about every conceivable modification has been discussed in this forum over the years. Or, perhaps, set up some type of polling for each phase. For instance... should the fuselage be 3" wider. This way you know your developing a product that will be open to acceptance. THERE IS ALOT OF KNOWLEGDE HERE. I know there is an old saying about design by committee but it could not hurt to get the input.

[ColinB]

Well im always open to sugestions, however i dont want to sit around too much discussing and debating ideas id rather just get on with it

 

also i am designing this aircraft for myself and i have a pretty clear idea of what i want for the most part

 

also you have to remember everyone has different prioritys and needs when they come to building there aircraft, as it is for me im not worried about having any more than 2 seats, and extra baggage room can always be taken care of with wing pods

[Arbiter]

Hey Colin,

Congratulations on beginning a new and exciting design project! I wish you the best of luck as I too am working on a new airplane design. Mine is a conventional configuration, not a canard, but that's another discussion! I am looking forward to seeing how the project turns out! Do you have any preliminary sizing data you would share with us? Do you have any parasite drag or wetted area predictions? What set of design books are you looking to use? I am following Roskam's books for preliminary design (With Dan Raymer's as back-ups) for my main texts.... I'd recommend Bruhn for structures, and he does a good treatment of sandwich structures from what I can tell. It will be great to see how things turn out! Good luck, and keep the chin up through it. It's the long road to be sure, but it's full of learning and fun along the way!

 

-Chris

[mak790]

I am following Roskam's books for preliminary design (With Dan Raymer's as back-ups) for my main texts.... .

It seems that everybody uses Raymer's books special the thicker one "Aircraft Design: A Conceptual Approach" , do you also use his RDS program?

 

Seb

[Arbiter]

Hi Seb,

I do use Aircraft Design: A Conceptual Approach. I'll also be looking at his simplified homebuilt design book. I do not use his program because it is $15K last I saw. I am following the Roskam Design Series (AAA Software is their program, also $15K) which is programmable in spreadsheets without much difficulty. The most difficult part at this point is documenting everything properly, at least that's the part that has taken the most time. I am almost done with preliminary sizing. If there is interest on this site (Though I am making a conventional pusher design) I will post some of my documentation for review. I am not planning to do this for profit so I do not mind. Take care!

 

-Chris

[mak790]

I do use Aircraft Design: A Conceptual Approach. I'll also be looking at his simplified homebuilt design book. I do not use his program because it is $15K last I saw.

Chris,

Are we talking about same software ? Raymer RDS is available for about 100$ for students, and probably for non commercial usage also, but personally I was disappointed with it (I was expecting more modern menu, it's very similar to DOS), it's hard to work with it.

Btw have you heard about Airplane PDQ? it's a very basic software you can download demo version at their webpage, here http://www.davincitechnologies.com/AirplanePDQDemo.htm

 

There are also others programs, much more professional such as ADS - Aircraft Design Software, or J2 Aircraft Dynamics, direct links for it and some descriptions here http://www.homebuiltairplanes.com/forums/design-structures-cutting-edge-technology/4919-computer-analysis-those-designing-aircraft.html

 

Seb

[Arbiter]

Hey Seb,

If you want to professional version of Raymer's code it's $15K. Same for AAA. Now you are correct about student editions, they are much cheaper. However, I am not a student and have not had much luck in the way of negotiating the not-for-profit pitch to the AAA guys. I haven't looked into the other systems as I am following Roskam's design series of books. This series is pretty comprehensive for preliminary design, and their staff has been responsive. Though I cannot afford the code, Roskam does provide good clarity in his books. At this time I haven't found anything that I haven't been able to code up in Microsoft Excel. In my mind the only thing the codes would provide me is assurance that all of my design parameters are consistent, but that can be taken care of using Excel too, it just takes some creativity . Anywho, thanks for pointing out the other programs! I will be definitely using Xfoil and the similar suite of codes as necessary, but for the most part it will be my own spreadsheets. Thanks!

 

-Chris

[bhassel]

FYI - There was a series of articles that John Roncz did in Sport Aviation that included Excel formula's (as well as Lotus 1-2-3 - blast from the past).

 

Besides being an interesting read, it might give you something to bounce against.

 

As an EAA member you can search/read/download pdf articles from any issue ever published. It's a recent upgrade but wow have I found some interesting stuff!

 

Bob

[ColinB]

im not a member of the EAA, as im not a US resident

 

I am part of the LAA that covers the UK market

 

unfortunately we are a lot more restricted over here, so because of this i will be limited on certain things

 

the main one being engine choice as we have a power limit, (we also have sky high fuel prices too) so because of this the most likely choice is going to be the Wilsch diesel engine

 

on the upside, i did speak with the chief engineer for the LAA today, and he doesnt seem to have any issues at all with my proposed change in materials as long as they meet the required spec (and they do)

 

i am considering looking into the effects of honeycomb core for a molded/ribbed wing but this could be quite a lot of work, i will need to consult with some people on that at the LAA