This professor giri and teaching is taking up a lot of my time.  Had a long chat with sandy. Few pointers one must keep in mind with delta is that.

1. CG with such wing is one very critical aspect. Estimating it is a pain. Sandy tells me there is an app for that. Apps litmus test would be this project

2. Engine mount into the wing would need to be slideable so as to match the cg

3. Heat generated would be high. Some protection would be needed near the tail pipe zone. Though it is not a mandatory requirement coz exhaust velocity sucks in surrounding air which acts as a heat shield

Wing would be better place for rx sandy. I would keep it away from vibration heat and metallic shield and spark

Very interesting sir. Subscribed.

Tiled plan has been joined and it's a huge plan. A0 size literally. What was I thinking  

If I don't use the inner most ribs two of them for symmetry then wing span works out to 32" and it's perfect for me as of now.

Sandy sir, I am sure you have thought about and taken care about it, but still good to flag it up.
I assume your are reducing the fuse build up, thereby also reducing the profile area, are you compensating this by some means? Increase in fin/rudder area perhaps?

Absolutely Captain. It will have twin Rudder fins in the wing tips with increased size to compensate. As such length of pulse jet will also makeup to an extent for the lack of original fuse.

I had taken sufficient care in joining the 20 A4 Sheets of tiled plan. Inspite of that I was not satisfied with the alignment of the final result. It had lot of misalignment at critical parts. So went ahead and printed out the plan in an A0 printer in full size two copies. What I realized was that the original was even bigger than A0 size and I had to reduce to fit inside A0. Effectively now the entire plan has been printed out and the final wings span of reduced size luckily turned out to just 34". Now I don't have to drop two ribs and I can construct as it is as per plan.

I flew this model during my NCC tanure.
It was a speed model(control line)
It was very fun to fly it.
We used O.S. .15 glow engine and 20*10 glass fiber prop.(without nitro)
It covered 10 circle of radius 19m. within 22.45sec.
So very excited to see it flying it with pulse jet.

I doubt it can fly on a 0.15 size engine. This original plan is designed for size 0.46 engine size and recomended engine is 40 size equivalent 2 cycle/ 2 stroke.

Sir,a test run parallel to the build will excite us more,just check the weld on the pulse jet before start.

JK

Yes I have heard some weld giving away on getting red hot. Not a bad idea for parallel test run for few seconds though atleast to get hang of starting blues. Should not be an issue at all since its with latest Nozzle.

Extreme flight of outlaw with Hobbyking pulse jet

One more flight video by others

I bet no NCC unit ever had this model. And C/L? You must be kidding

If I remember right C/L speed was on 35 feet lines. This size model even with 35 feet lines will not be able to pull its own and line weight with 15. Let alone do it in 22 odd seconds

Flyingboxcar then you must visit Jaipur Ncc campus. As i said i flew it with .15 engine and it was a c/L model so it's wing span was 40 cm only.
I'll post pics of that model if i visit that campus again.
Shobhit Sir know's coz he was commanding officer that time.

Hi Antriksh your earlier post was in a way implying that you had flown the very same model in this thread. Wing span of this model is 40" (inches) and which is approximately 1 Mtr/ 101 Cms therefore the clarification by me and Captain.

I am sure you would have flown a 40 Cms wing span delta model with a 0.15 Engine on CL. A 40 Cm model is very much possible with a 0.15 Size engine.  

Using the data provided, ie 19m (say 60ft), and 10 lap time of 22.45sec, we get a speed of 168ft/sec or 182kmph. That sounds correct for a CL speed model.

But 168ft/sec is 10080ft/min. So if the stated prop size (20x10) is in cm, 8"x4", the motor must have been doing over 30,000 rpm!
More likely that the prop was perhaps a 6x8 or so, which an OS .15(FP?) could possibly have turned at over 15,000 rpm on a healthy dose of nitro.

Anyway, good to hear some CL talk...

Wowww! Wowww Wowwww!! ... My fetish for Delta would take a whole new turn! With "Hai-2" Flying wing still 60% Complete on my workbench and Kyten Delta Kit bought from UK still in Closet, I think this Pulse Jet Engine (Poor Man's Turbine Jet for paupers like me) is enough compelling reason for me to jump in.

I am planning to CAD the plan like I did for Hai-2. Sundaram sir, if you have rough sketch for the Engine pylon, do share with me. I would include it in my design and would see if we can incorporate FRC paneling and some heat retardant covering around the Jet.

Do share your tips on the Pulse jet too, as it is a very rare power plant and your experience in tuning it could save laggers like me to save from dead sticks.

Sure Ujjwal will surely be adding more sketches and details and complete experience on tuning and test runs too. Definitely noted to include Engine mouting details too.

Iyer Sir. Its 191.51 Kmph to be precise {[(2*22/7*19m*10laps)/22.45secs]*3600secs}/1000m.

An 8x4 2 blade should achieve it in 11200 RPM says my phone RC Tools app. Is it way of the mark? I have been too dependent on it till now for my static thrust estimation and speed calculations. 

Iyer Sir's air screw analogy applying  Prop pitch 4" 12000 RPM works out to 200 R/Sec which is 800 inches per sec forward travel which is 20.32 mtr/Sec i.e 73.15 Kms/hr. Wonder how the app is calculating double this.

Professor Gusty is desperately needed here.

Iyer Sir my Phone app sure has a bug. Its calculating Correctly in mile per hour accurately  as per our analogy but Kms/hour is way of the mark and in fact is not changing at all with change in pitch of prop only Miles per hour is changing.

Thanks Antriksh for the invite. There is a lot of difference between a 40cm model and this one. Not all delta's are same

Iyer sir,
an OS 15, without any nitro on a 8x4 (coarse pitch) prop doing 190 Km/h is something hard for me to digest.   
Even on a 6x8 the stock OS will not do 15k on rpm
BTW The current ratified FAI F2A record is 307.4 K,/h per the FAI site

Also you cant literally go by the pitch of the prop !  Little bit of prop theory is here, and in the thread

If pitch of a prop is said to be 4", it will give you that forward pull only in a zero drag condition (i.e without being attached to a aeroplane or an engine ) this is called GMP. PP (Practical Pitch is always less and it depends on (a) Aeroplane design (b) Speed at which it is travelling. Higher Pitch props unload at high speed and peaks on speed performance at its optimum speed, above and below it that prop under-performs

Any 4" prop will not give a PP of over 3.2" nothing more

Yeah Sandy ! software has a bug, not your phone

Logical question would be what happens to a 3 bladed or 2x3 bladed contra prop ?

I am not going to answer that, let us throw this question open for discussion

Thanks Gusty. Now when its ratified by gusty we are definitely reassured.  

This one below is specially for Ujjwal Jhon . Wonder how they managed to fly four of them together with same colour scheme in same pattern and at such speeds.  



PS : Now its high time I stopped jabbing away on the key board and start building some.