Welcome General Eclectic, a really good start,i look forward to hearing more...:-)
Can't think of anything intelligent to say really. Oh yes...did you realise that you look a little like Sir Frank Whittle? And why not! I say, when an engine such as the Avon is reworked to power an electrical generator, for example,how many more turbine stages are required to use up all the residual thrust? What I mean is (remember I am a simple pilot only)if the compressor requires about two thirds of the total energy to drive it at operating RPM, how do you know how many more turbine blades will be required to provide the net SHP? That is about the clarity of the Thames....
Well, dakota67, it's not a resemblance I had ever noted, but how nice of you to mention me in the same sentence as the great man..., and then ask me a jet engine question. Phew, no pressure. Oh, and if any of you properly talented propulsion engineers at any of the mighty powerplant companies would care to step in and correct the following, I would not take it as a slur personally or professionally. Just be nice. :-)
Right, this is the limit of what I remember, based on not being able to find my university notes on the subject... The number of blades on a given stage is chosen as much as possible to not be the same as a previous stage. If you match the stage before you get a very strong pulsing that is very bad structurally and if you match the number elsewhere in the engine you can get a weird harmonic that is bad for the vibration levels.
The annulus (the flow area) is sized for the volume flow with the inside and outer diameters being limited by things like the mass of the turbine disk and the stresses in the root and tips of the blades.
The throat, the gap between the blades, is chosen to extract the maximum of energy at a given stage whilst not being so restrictive that it chokes the flow between blades.
How all this adds up is for cleverer men than me.
In the structure in which I worked, the Performance Engineers worked out stages, the Aerodynamicists worked out the theoretical blade profiles and throats(using in-house Fortran codes; they were good old fashioned boffins and I was humbled by their understanding), and the Designers worked with the Stress Engineers to produce individual blades with their labyrinthine cooling passages.
With combustion cans (gas turbines, remember) it was the same: take a fuel with a given calorific value, ask a Chemist / Combustion Engineer to tell you what fuel / air mix and flow rate you needed so you could design a nozzle / swirler assembly. Ask the same Chemist / Combustion / Acoustics Engineer what sort of residency time he needed for the flame to size the diameter and length of the can and then design a product with enough film and impingement cooling that it didn't melt, the right amount of quenching flow that flame didn't fall out out of the sweet spot of too much / too little combustion (it effects the NOx emissions and other nasties) and not so much air wasted on cooling that the efficiency of the system starts to drop significantly.
Teamwork means you don't have to be brilliant at everything. Thankfully.
I've flown on A330s, 747s and 777s and to be brutally honest I didn't really notice a huge amount of difference (Though admittedly, I'm not a frequent flier). The only one I really remember thinking "Oh, this is nice" about was one of the 777s but that was because it was obviously still very new.
I love and am fascinated by aircraft but have to admit, when it actually comes to me flying I don't really mind what it's on as long as it gets me there safely.
If this is the case in your manufacturing environment then I'd say you were jolly lucky. Its a fact that the average age profile of the manufacturing/aerospace engineer is 45+ in the UK.
The industry is despaarate to encourage more young people to take up engineering as a carreer as opposed to service industries, IT or banking. The perception is that were all grubby and oily and slightly boffin'y, poorly paid and constantly being laid off !
Perhaps you have all the bright young things at your firm so the rest of us have to cross our fingers for the future ?
Hi Vtol, thanks for the comment, I wonder what has given me such a different impression?
There are several similarities in the companies I've worked in. Firstly, they are all tier 3 suppliers - supplying engine manufacturers with systems of one sort or another. The secondly is that I have worked more in the Engineering offices than in Manufacturing and lastly they are all in the UK or France.
There was a definite contraction a few years ago that saw redundancies at the company I was at at the time. Not surprisingly the first to go were the nearest to retirement and this dropped the average age in our office in one swoop. As I said in the post, a parting CEO mentioned in the press the (lack of) experience in another company I know.
So have I really discovered the pockets of youth, am I misinterpreting, or is experience poorly distributed in the industry? At least it gives me hope that there are people out there to learn from.., but that's for another post.
It's good to have you back General, we've missed you :-)
Thanks Mav. I really feel that I've not been pulling my weight around here recently and I'm looking forward to re-engaging (he said using horrific manager-speak).
It's good to hear from you again General,what's good about this industry is the variety and that things are always busy!
Thanks Mav. My current customer, an hour's commute and a wonderful family are keeping me away from the site more than I'd like, but I'm still here.
On the subject of the post.., I guess the staff at Flight see the variety in the industry more than most.
Happy to have you along. Just one problem - I think we've got some competition for the next amphibs package :) It was a wonderful experience from start to finish, though, without a doubt. I'm not sure if you saw my video blog about Seaborne, but just in case, here it is: www.flightglobal.com/.../video-seaplanes-st-croix-and-h.html
Well, if you had only made it sound like an awful experience the queue wouldn't be half as long :-D.
Thanks for the link to the video; it really looks like a great operation and I’ve really enjoyed your coverage of it. I have to say, though, that the video did absolutely nothing to help me address my rampant jealousy.
Best Regards and Safe Journeys.
Go for it! and All The Best to you and your Family.
Thanks Flyer1, I appreciate your best wishes.
Amazing, the first time a take my girlfriend to fly was perfect.
Helicopter flight around the "Cristo Redentor" Rio de Janeiro - Brazil.
Excelent post.
Regards
Rocha
If the statistics are to be believed, the pilot population is both ageing and shrinking. Unfortunately