Get off my LAWN! "Grumpy Old Farts"

[Al Kraft]

I was thinking the high pressure compressor/turbine assy. spun faster than 15k RPM. I was sure the low pressure section was much slower simply due to the diameter.

Still supremely impressive given the heat and loading.

It varies depending on the engine, but the speed range I recalled was specifically from the version on the Lufthansa A320 birds back in the 2000 time frame (don't ask). As you pointed out the larger diameter high by-pass turbofans are getting supersonic tip speeds even at these low RPMs and creating some pretty significant stresses. Larger internal engine diameters are also part of a trade off between performance and reliability, with weight as a nagging factor that cannot be forgotten in any aviation design problem.

IDK how much NDI they can do now for the blades. During my time is was a boroscope (camera), a mech and QA. Other parts had different tests, like some bolts were coated with a dye, then inspected under UV light to check for cracks. We never lost a blade in flight or on deck.

Ultrasonic inspections are a very useful NDI technique for this type of thing.

The US military needs that promised large infusion of funding to keep to keep the aircraft in the air.

Invalid Link Removed

Dozens of F-35 fighter jets grounded in US due to oxygen deprivation

The list goes on....

More tragic is the high and increasing number of training deaths.

One of my colleagues is on the Blue Ribbon Panel working the physiological episode issue and also worked with the NASA independent review team who was helping the Navy look into this originally. While the initial concern focused on simple incidents of suspected hypoxia, it turns out that the usual suspects didn't really tell the whole story. IMO we've pushed a lot of things to the extreme edge of performance and the limits of human physiology, but may not be addressing every potential contributory issue as thoroughly in our daily routines as we could. This problem is not as straight forward as initially thought, there are many variables in play.

 

[Al Kraft]

Flying on a wing and a prayer should be the exception.

Well the wing part is probably okay depending on design and proper maintenance...but as we like to say in Naval Aviation, prayer and hope for that matter are not strategies for success.

 

[agedhorse]

I worked on some natural gas turbine powered peaking/co-gen generators (in the 5-10MW range) years ago (the electrical side), which used smaller diameter engines (from memory the air intake at the front cowling was maybe 4' in diameter) and there was a significant reduction gearbox (might have been a planetary type after pulling the load off of the engine shaft like an APU), but I recall the gear ratio was pretty steep because these were at least 4 pole generators (which have a shaft speed of 1800 RPM). I am almost positive that these were GE engines, hearing protection was absolutely mandatory.

There were some special cooling considerations as well due to being operated at low altitude, higher ambient temperature conditions. Something about increasing the bleed air around the core of the engine to remove the additional heat. Also there was some sort of trick to capturing all that waste heat for co-gen. It's been probably 30 years since I have thought about this.

 

[Al Kraft]

I worked on some natural gas turbine powered peaking/co-gen generators (in the 5-10MW range) years ago (the electrical side), which used smaller diameter engines (from memory the air intake at the front cowling was maybe 4' in diameter) and there was a significant reduction gearbox (might have been a planetary type after pulling the load off of the engine shaft like an APU), but I recall the gear ratio was pretty steep because these were at least 4 pole generators (which have a shaft speed of 1800 RPM). I am almost positive that these were GE engines, hearing protection was absolutely mandatory.

There were some special cooling considerations as well due to being operated at low altitude, higher ambient temperature conditions. Something about increasing the bleed air around the core of the engine to remove the additional heat. Also there was some sort of trick to capturing all that waste heat for co-gen. It's been probably 30 years since I have thought about this.

For decades GE has been repackaging their turboshaft (helicopter) and turbofan/turbojet engines to provide everything from power generation (main, back-up, and peak demand supplemental systems) to pumps for cranberry bogs to main ship propulsion systems. The mass airflow is the same as for an aircraft application and while in a ground based system you can spend a little extra weight on soundproofing, at the end of the day these machines make some serious noise. There are some small APU's that run in the 40,000 to as high as 50,000 RPM range such as the old Garrett/AiResearch GTP and GTCP units. These can be found in aircraft (military and commercial) as well as in ground carts for aircraft ground starting and servicing.

You may even recall that at one time (mid 60's) Chrysler had some prototype turbine powered cars that never got to production and Allison experimented with gas turbines in city bus fleets for a while (in the 70's I think).

 

[Passinwind]

You may even recall that at one time (mid 60's) Chrysler had some prototype turbine powered cars that never got to production and Allison experimented with gas turbines in city bus fleets for a while (in the 70's I think).

I saw this Howmet turbine car run at Watkins Glen ca. 1968, where it placed third against a pretty stout field of Le Mans cars. It actually won a couple of lower caliber races that year as well. You could clearly hear it even at the furthest distance from your vantage point at The Glen, which was one of the longer tracks in the US at that time.

A couple of decades later I also saw several turbine powered unlimited hydroplanes running on Lake Washington, which was even more impressive in many ways.

 

[biguglyman]

Google Image Result for http://granatelliturbines.com/wp-content/uploads/2014/12/Lotus-70-indy-500-slider-image9.jpg

 

[Passinwind]

Google Image Result for http://granatelliturbines.com/wp-content/uploads/2014/12/Lotus-70-indy-500-slider-image9.jpg

There was a Formula One version of that Lotus Indy car too, but it was also neutered into oblivion pretty quickly.

 

[beans-on-toast]

People in rural areas have had to contend with solar and wind turbine power generating systems that are cropping up. There’s a lot of opposition.

This isn’t about a land owner putting up some panels. In some areas, farm fields as far as you can see near communities have been taken over by arrays of solar installations. They are also clearing forests which affects the local water table. These arrays are ugly. I don’t know why the government doesn’t force them to install the arrays in a basin below ground level so they can’t be seen or at least plant trees around them. Obviously due to cost and loss of profit for large power companies.

The biggest opposition relates to the large wind turbines. There aren’t many of those in the countryside around here. People that live around them complain of health issues because of the constant low level noise and from simply seeing them destroy the countryside. It apparently stresses both people and the farm animals.

People move to the country to get away from the constant din of the city where the noise from all the buildings and traffic never goes away.

 

[BadExample]

I go through a huge wind farm on the way to visit my mom. They go as far as you can see and it's the epicenter of flat lands. Feels erie. Almost like we're infiltrated.

 

[40Hz]

I worked on some natural gas turbine powered peaking/co-gen generators (in the 5-10MW range) years ago (the electrical side), which used smaller diameter engines (from memory the air intake at the front cowling was maybe 4' in diameter) and there was a significant reduction gearbox (might have been a planetary type after pulling the load off of the engine shaft like an APU), but I recall the gear ratio was pretty steep because these were at least 4 pole generators (which have a shaft speed of 1800 RPM). I am almost positive that these were GE engines, hearing protection was absolutely mandatory.

There were some special cooling considerations as well due to being operated at low altitude, higher ambient temperature conditions. Something about increasing the bleed air around the core of the engine to remove the additional heat. Also there was some sort of trick to capturing all that waste heat for co-gen. It's been probably 30 years since I have thought about this.

My dad was a mechanical engineer. He worked for Avco-Lycoming in the 60s and 70s doing turbine engine design. Their T-53 and T-55 engines were his thing while he worked there mostly on designing transmissions although he also worked on a recapture technique for rechanneling the exhaust stream from the back into the turbofan for an additional no-cost power boost.

Avco was one of the earliest US companies to regularly use titanium IIRC. One of the company’s scientists had figured out a way to weld it (big deal back then) which was Avco’s big manufacturing advantage.

Wow! Haven’t thought about any of this in years.

 

[Ken Morgan]

There’s seemingly 100,000 wind turbines within 50 miles of my front door. Odd to see turbines, oil pumps, cattle, and cotton all in the field, but there they are

 

[beans-on-toast]

Beef cattle are tougher beasts than dairy cows. In the north east, most cattle farms are dairy. Anything that affect milk production is taken seriously. The poor bulls are outside freezing during the winter, the cow's teats are too sensitive to be outside so they remain in the barns. In the spring, the cows take over the fields close to the barns where the bulls were. You rarely see any bulls during warmer weather.

 

[BadExample]

Yet being outnumbered many:1, the bulls remain happy.

Mow cow here is meat cow. By the 70's most of the farmers I knew kept the bull in a nitrogen freezer in the form of purhased sperm in vials. Thusly, many farmers had one finger to armpit length rubber glove.

 

[beans-on-toast]

Poor bull.


With the popularity of greek goat yogurt and cheese, I see a growing number of huge goat farms. They never see the light of day. The thing is, goats are very social, they love to come over, get a pat and say hello. They probably don’t get much of that in a big operation.

 

[BadExample]

Poor bull.

Some bulls are into that stuff. Some like big utters.

 

[BassmanPaul]

If this is not accurate, I blame the BBC and Sir Paul, The Brit.

Don’t blame me for Auntie BBC!

Add to that I was British I am now Canadian you Wild Colonial Boy!! LOL

 

[BassmanPaul]

It’s amazing what gets posted by Grumpy Old Farts!!!!

LOL

 

[BadExample]

Don’t blame me for Auntie BBC!

Add to that I was British I am now Canadian you Wild Colonial Boy!! LOL

Sir Paul, the unjustly blamed, with all respect, I must say after working in technology for 35 years, both public service and private sector, the only thing that doesn't change is you can and will be blamed for stuff before you came on board, during your tenure, and after you leave!

We had a cigarette TV ad here that went something like, "You can take the Brit out of the UK, but you can't take the UK out of the Brit."

 

[BadExample]

Okay. Back on topic.

There's this large farm with three bulls. The same three bulls have been there for years and who gets who is all settled. They get along well. The large bull gets 70% of the cows, the hot ones. The more average sized bull gets 25% of the cows, the OK ones. The poor scrawny bull gets the leftovers, the really homely cows. He's even smaller than a few of the cows, and really only has little nubs for horns.

So, they hanging out doing what bulls do, and they hear the farmer telling his wife the new bull is coming in today. So the large bull starts huffing and puffing and kicking up dust and says, "Well, he's not getting any of my cows!" Then the regular bull kind of snorts some and kicks a little, looking back and forth and says, "He's gunna hafta put up a fight to get any of my cows." And the small bull just rolls his eyes back and thinks to himself, "This is BS."

Then they hear the rumble of a diesel engine and see a big dust cloud from a big flat bed coming down the road. Once it pull onto the lane and the dust, they see the largest bull they ever saw. Bigger than the bulls in the naughty back pages of bull-boy magazine even! The big bull nervously says, "uh-h-h-h, let's welcome our new bull. He can have a few of my co-o-o-o-ows." The medium bull says, "Screw this, he can have what he wants of mine, I'll take the ugly cows!" Then the tiny bull starts huffing and puffing and kicking up more dust than the other bulls ever did. So the other two look at him all pie eyed and one asks, "What the heck are you doing?!?!? are you nuts???"

The small bull replies, "I'm making damned sure the new bull knows I'm a bull."

 

[beans-on-toast]

Settle down or I’m going to turn the car around.


Juice Newton does a lovely job on a couple of her hits. She’s good.




Southside Johnny....