Question to the MA2A brain trust.......... specifically those who have worked on / serviced jet engines as I have remembered past conversations to have drifted too.
What is the typical injection pressure fuel is presented to the combustion chamber within the jet engine? Asking because i was asked to review a technical paper on jet fuel atomization and the paper is working in pressures of 1500 bar (21,700 psi) and that really seems more diesel injection pressures. I typically work with systems that are in the 2,000 to 2,500 bar (29,000 to 36,000 psi). My understanding of jet's is limited but since the fuel flow is continuous in nature and that requires a constant flow hydraulic pump I would have expected operating pressures to be 400 bar/6000psi or less.
Any comments or guidance that can be shared would be appreciated!
Thanks,
Dan
DanNehmer wrote:
Question to the MA2A brain trust.......... specifically those who have worked on / serviced jet engines as I have remembered past conversations to have drifted too.
What is the typical injection pressure fuel is presented to the combustion chamber within the jet engine? Asking because i was asked to review a technical paper on jet fuel atomization and the paper is working in pressures of 1500 bar (21,700 psi) and that really seems more diesel injection pressures. I typically work with systems that are in the 2,000 to 2,500 bar (29,000 to 36,000 psi). My understanding of jet's is limited but since the fuel flow is continuous in nature and that requires a constant flow hydraulic pump I would have expected operating pressures to be 400 bar/6000psi or less.
Any comments or guidance that can be shared would be appreciated!
Thanks,
Dan...Show more →
I began writing a whole lot of 'stuff' about 'stuff' that I think was irrelevant. I don't ever recall "measuring" fuel pressure. When engine performance degraded, it was noted via other measures, loss of power, EGT, EPR and a few other acronyms specific to an airframe/engine manufacturer. If I was to guess, I would say the fuel pressure was a low pressure system. Unlike the hydraulic system which requires high "pressure", the fuel system requires a high "rate". My guess would be 100-160 psi. That is not scientific, simply a guess, but I do not recall ever measuring fuel pressure. Someone could say "the fuel system doesn't have enough pressure to run the engine", however, the reality is the system is not producing the required fuel flow (rate). Keep in mind some engines require a fuel heater to keep the high rate of fuel warm. You would not require a heater if you were pressuring it up to 6000 psi.
I know that doesn't answer your question, sorry Dan.
Rodolfo Paiz wrote:
All electric cars respond instantly, since electric motors have 100% torque at all RPM.
Hello Rodolfo. I just joined the electric car club last week. This is after driving BMW's for over 20 years.
The torque is amazing and I'm loving it so far. It's a very different experience, especially with 1 pedal driving. Didn't use the brake pedal during a 25 mile commute this morning.
Thanks for that answer. It helps more than you know. It puts scale to the possible injection pressures; older military engines are not likely to run high pressures, that said even modern jets wouldn't need 100X increase in the fuel delivery pressure. And yes, I fully understand your point, EGT's, Power, Turbine speed would all be good indicators of low fuel delivery which is the likely the information you need begin repairing the engine. And the comment that hydraulics are high pressure at 6,000 psi confirms that fuel pressure is much lower; if fuel pressure was that high you would know it from type of supply lines, pumps, seals, etc.
bkp944 wrote:
The torque is amazing and I'm loving it so far. It's a very different experience, especially with 1 pedal driving. Didn't use the brake pedal during a 25 mile commute this morning.
Yes, very different... but you get used to it in about two minutes and then it seems totally natural!
I've heard wonderful things about the Mustang Mach-E. May it serve you long and well, and provide unending gobs of fun!
My Buddy Joe Dobransky is picking up a new Husky at the factory in Wyoming sometime in the next week or so. He called me in a panic to see if I could find him hangar space and, of course, I couldn’t have Joe anywhere but in with me so I moved a Cirrus to another hangar and gave him front and center at HQ. so Joe rolls up in a black Tesla model something that has 60k in performance mods , because 2.3 seconds isn’t quite quick enough.
I think the technology is amazing and we should obviously be exploring it, but , like radial engines, I like my speed to have plenty of audio accompaniment. I lose interest rapidly if it doesn’t make your heart pound when it is sitting there idling. I don’t really care if it takes longer to 60, as long as it rumbles and pops while it’s doing it. But then I’m just one old guy that thinks a battery is great, to light up something with big pistons.
JWilsonphoto wrote:
My Buddy Joe Dobransky is picking up a new Husky at the factory in Wyoming sometime in the next week or so. He called me in a panic to see if I could find him hangar space and, of course, I couldn’t have Joe anywhere but in with me so I moved a Cirrus to another hangar and gave him front and center at HQ. so Joe rolls up in a black Tesla model something that has 60k in performance mods , because 2.3 seconds isn’t quite quick enough.
I think the technology is amazing and we should obviously be exploring it, but , like radial engines, I like my speed to have plenty of audio accompaniment. I lose interest rapidly if it doesn’t make your heart pound when it is sitting there idling. I don’t really care if it takes longer to 60, as long as it rumbles and pops while it’s doing it. But then I’m just one old guy that thinks a battery is great, to light up something with big pistons....Show more →
AKA "Gearhead"!
Wonder when the Feds and states will begin excise taxes on the charging stations at home and on the road. They are going to have to replenish the highway funds lost from fossil fuels...it's coming, we just don't know how much or how! Typical gov't program. Get people to change, then tax them for changing once it becomes acceptable, or too large to go back.
The fuel tax was a great idea, and was VERY helpful in building the incredible network of roads and highways in the USA, and it's a reasonable approximation of pay-for-what-you-use. Pity that it hasn't been increased over time and hasn't even kept up with inflation, because that contribution is sorely missed.
But two changes need to be made: the fuel tax amount needs to go up, and electric cars need to be charged somehow. Maybe an annual mileage fee per vehicle, where you pay for having driven X tons over Y miles regardless of vehicle type of fuel type... or something.
Rodolfo Paiz wrote:
I've heard wonderful things about the Mustang Mach-E. May it serve you long and well, and provide unending gobs of fun!
Thanks Rodolfo!
Everyone is right about how to fund road projects with the proliferation of EV's coming soon.
Oh the ex Indiana mayor is very interested in floating that mileage tax idea, they'll get it one way or another. I find it interesting that California is encouraging electric vehicle operators not to charge their cars due to the rolling black outs. Man, you can't have it both ways! Let's not even approach the subject of how the highway fund has been raided over the years like social security. We've been lied to so much, by both sides of the aisle that I don't believe anyone any more.The swamp is alive and well and is only getting stinkier.
Chandler and I saw one of the Mustangs outside a spot where we were having dinner night before last, it looked very nice! How long did it take you to get yours, given the chip shortage?
Wonder when the Feds and states will begin excise taxes on the charging stations at home and on the road. They are going to have to replenish the highway funds lost from fossil fuels...it's coming, we just don't know how much or how! Typical gov't program. Get people to change, then tax them for changing once it becomes acceptable, or too large to go back.
Right you are Ray! This stuff where the movie theaters are putting in free charging stations at close in parking slots is just an automotive mousetrap.
JWilsonphoto wrote:
Right you are Ray! This stuff where the movie theaters are putting in free charging stations at close in parking slots is just an automotive mousetrap.
Yeah, I remember recycling paper grocery bags, then, BAM! They were not green enough, we had to go to plastic! We use to recycle the grocery bags with newspapers at paper drives for our schools. Then, BAM! Plastic bags are bad, in Austin you get paper grocery bags. Funny, they never, ever said newspapers and magazines were bad? That tells the story, lies, lies and more lies!
"Mustang" on an SUV....and their new mini truck is going to be called a Maverick...either the Ford marketing guys have lost their minds or the public is so....er, um...uh....vapid that it doesn't; matter.
Just like Goodyear refusing to stop calling their airships 'blimps"
SMH
JWilsonphoto wrote:
(deleted) I find it interesting that California is encouraging electric vehicle operators not to charge their cars due to the rolling black outs. Man, you can't have it both ways! (deleted)
Not only that but, many parts of California (possibly the entire state) require that new homes be all electric. Many jurisdictions are also requiring replacing gas appliances and systems with electric during remodels, and major renovations.
All this in a state that can't guarantee adequate supplies of electricity when the weather gets hot, and will deliberately shut down the electric grid (for days) in hot windy weather to reduce the risk of wildfires,
Love our gas furnace, hot water heater, stove and oven. Also love the 3500 watt gas generator that will keep the fridge, and freezer operating when they cut the power.
Politicians (probably true in more places than just California) try and impress the rubes with how intelligent/enlightened they are. I just look at most of the laws they pass scratch my head, and think "Really?".
JWilsonphoto wrote:
My Buddy Joe Dobransky is picking up a new Husky at the factory in Wyoming sometime in the next week or so. He called me in a panic to see if I could find him hangar space and, of course, I couldn’t have Joe anywhere but in with me so I moved a Cirrus to another hangar and gave him front and center at HQ. so Joe rolls up in a black Tesla model something that has 60k in performance mods , because 2.3 seconds isn’t quite quick enough.
I think the technology is amazing and we should obviously be exploring it, but , like radial engines, I like my speed to have plenty of audio accompaniment. I lose interest rapidly if it doesn’t make your heart pound when it is sitting there idling. I don’t really care if it takes longer to 60, as long as it rumbles and pops while it’s doing it. But then I’m just one old guy that thinks a battery is great, to light up something with big pistons....Show more →
Not quite an analogy but it sort of illustrates how technologies have changed. I was shooting hummingbirds two weeks ago at a garden, there were 5 or 6 other photographers at the popular spot, when the hummingbirds flew in to hover over the flowers, I could hear rapid firing shutter sound from the their DSLRs like machine guns firing, I was shooting 30 FPS with my Sony A1 in complete silence with the electronic shutter. Sure the DSLRs "sound" more fun!
Since I am posting, may as well post a few shots from Sunday's outing.
This is different shot from the first one, but in the same sequence.
Ray Swindle wrote:
Yeah, I remember recycling paper grocery bags, then, BAM! They were not green enough, we had to go to plastic! We use to recycle the grocery bags with newspapers at paper drives for our schools. Then, BAM! Plastic bags are bad, in Austin you get paper grocery bags. Funny, they never, ever said newspapers and magazines were bad? That tells the story, lies, lies and more lies!
Ray
Good point Ray, and how about that tree limb of paper that comes every month in the mailbox, about 95% of which goes straight to the landfill? Ever heard on of our "distinguished" leaders wax poetic about eliminating junk mail.................?
Chandler and I saw one of the Mustangs outside a spot where we were having dinner night before last, it looked very nice! How long did it take you to get yours, given the chip shortage?
Thank you Jim! This one was a demo at a local Ford dealership and they were required to keep it 4 months before they could sell it. We are in a rural area of Tennessee, so there wasn't hardly any interest in it.
It was equipped exactly as I wanted - except for the color! I've always had dark cars.
But, when I found out it would be after the first of the year before I could receive the one I wanted, we agreed that I would buy the demo immediately when it become available.
BTW, Ford should have simply called it the Mach-E, but that's a separate discussion
Typical gov't program. Get people to change, then tax them for changing once it becomes acceptable, or too large to go back.
