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Re: Triumph to Tragic in one fell swoop.

Posted: Tue Aug 28, 2018 12:32 am
by Canopener Al
Interesting discussion after my last post Gentlemen and i admit I have never seen the full transcipts of any of the trial runs bar on "Across the lake " and written in "the Record Breakers". I am an ex RAF Airframe guy by starting trade, tin bashing at first, did Mechanical ONC and HNC as education and did engines conversion at the end of my RAF career, then into the B1 world of civil aviation and all the taking of exams to refresh EASA that I knew what i was doing as a competent person. No engine in the world is not designed to be able to draw the fuel required to operate under its full range by its own plumbing system. That would have incudled the Orpheus. As Bill has mentioned however the HP fuel system on the prototype Gnat was not a standard engine. Also the FRAME fuel system was designed orignially for the lower requirements of a Beryl. The Intake design and loads of K7 for a Breyl was not strong enough for the Orpheus suction loading. Such is the way for low cost modifications that k7 got in 66. PV/T = C is thermodynamics Gas laws.. Fluid Dynamics is a little similar. Also, Blue Bird was on the plane under the four forces of Thrust, Lift, Weight and Drag. Remove one of them suddenly and the normal world is disrupted.
:evil:

Re: Triumph to Tragic in one fell swoop.

Posted: Tue Aug 28, 2018 12:52 am
by Canopener Al
Mike, I assume the LP indication is a suction based one. You are using original pipe dimensions that caused DMC and LV all the same problems 52 years ago?

Re: Triumph to Tragic in one fell swoop.

Posted: Tue Aug 28, 2018 7:35 am
by Engine 711
In anything to do with K7 and particularly 4Jan67, it is best in my view, not to be too 'absolute'. There are lots of things that are still not known or properly understood - although running the actual boat will help, in increasing overall understanding.

There is also lots on information and many views & opinions, in the various books written. Some are very good, others less so. Actual experience & evidence, will (or should) override all of these, but the books are still worth a read. Authors have found information which was hidden away for years, which can be crucial to improving our understanding - such as the 'new' bits of film found, from various sources - beyond the classic BBC and ITN footage.

Re: Triumph to Tragic in one fell swoop.

Posted: Tue Aug 28, 2018 8:02 am
by Richie
Were you an engineer for RR ?


I didn’t know that....

Re: Technical Talk

Posted: Mon Sep 03, 2018 5:10 pm
by strath_uni
Hi, I am going to run undergraduate student projects in 2018/19 looking at the aerodynamics and stability of the Bluebird. This will use both CFD and low speed wind tunnel testing. To do this I need the external lines of the Bluebird. Does anyone know where I might find these in 3D CAD format?

Re: Technical Talk

Posted: Mon Sep 17, 2018 12:18 pm
by Renegadenemo
Hey, Bluebirders... anyone live close enough to the Solent museum to go and get some techie shots of the Beryl engine there? With particular attention to the fuel control system and its linkages? That would be very useful to us.

Re: Technical Talk

Posted: Mon Sep 17, 2018 10:20 pm
by Canopener Al
Shame I didn't see this until tonight. Was there this morning. I did take a picture of it.

Re: Technical Talk

Posted: Tue Oct 02, 2018 9:17 pm
by ted.walsh
anyone looking for half an hours worth of jet powered drag car entertainment? then look no further than here...https://youtu.be/l4bbR06I83Q

Re: Technical Talk

Posted: Sat Oct 06, 2018 8:13 pm
by Gareth Hayes2
Note: if this topic upsets or offends anyone, please delete

I was looking through some of the crash footage earlier today (yes I am that sad). When I saw something puzzling & intriguing. Just after the large splash of Bluebird entering the water, there were two smaller splashes. It doesn’t take a genius to work out what caused one of the splashes, & I’ve no desire to push that avenue of inquiry any further. However, what about the 3rd splash? Have you any idea as to what that was from the boat that caused that?

Re: Technical Talk

Posted: Sun Oct 07, 2018 12:01 pm
by mtskull
Gareth Hayes2 wrote:
Sat Oct 06, 2018 8:13 pm
Note: if this topic upsets or offends anyone, please delete

I was looking through some of the crash footage earlier today (yes I am that sad). When I saw something puzzling & intriguing. Just after the large splash of Bluebird entering the water, there were two smaller splashes. It doesn’t take a genius to work out what caused one of the splashes, & I’ve no desire to push that avenue of inquiry any further. However, what about the 3rd splash? Have you any idea as to what that was from the boat that caused that?
This has previously been analysed very thoroughly on this forum; it's the left hand cockpit wall. Here's a quote from Bill Smith in which he explains the crash sequence. (I found this on the "Pic of the Day" thread, by searching for the word "splash"):

....the left sponson hit first and effectively levelled the front spar as the main hull continued to roll and twisted itself free. The cockpit frame failed first at the F-17 and F-19 horizontal crossmembers effectively flat-packing the cockpit sides against one another followed immediately by failures at both vertical frames that made up the cockpit sides at the same place, F-17 (roughly under the pilot's knees).
The right-hand wall from the cockpit rear bulkhead (F-15) to the tip of the bow (F-23) stayed together and sank in one piece, the left-hand wall snapped in two at F-17 with its after half sinking straight down and its forward half rolling completely under the boat to be spat out the opposite side like a skimming stone and splashing down 160m away. If you watch that video of the crash where it ends in three splashes with the safety boat in shot, the cockpit wall is the final splash.
The front spar tore out from left to right then glanced off the water and flew a further 120m along the boat's original track. It tore out the steering box, F-20 bulkhead and the right-hand cockpit rail as it went and deposited these some distance to the NE. The heavy sponson structure shot under the slowing spars stripping the upper fairings off with the left-hand fairing being crushed against the hull leaving some of it air-locked and floating whilst the right-hand fairings fluttered off in a loose collection of parts.
All the outer skinning from the left-hand side survived crushed against the frame while that from the right was blasted outwards in a million bits.
Having shed the cockpit and the sponsons the main hull entered the water on its side where the left air intake took a massive gulp of water and tripped the boat over, slamming it down hard onto her right-hand side. This crushed the other intake shut and hydroformed the side of the engine cover inwards between the formers for a distance of about six feet as well as bending the fairings on the tail fin away from the direction in which she splashed down and that's only what happened to the big bits.