Another Drone Pilot does it Again
07-27-2016, 12:33 PM
#3526
I beg to differ again. For a turbine engine to work AT ALL, it is constantly pulling air into the front fan. There is no way for it to pull air into said fan and not have negative pressure AT ALL TIMES!!!!!!!!!!!!!!!!!!!!!!! Roughly 80% of the air pulled through the fan goes around the engine, creating an equal percentage of thrust. The other 20% goes through the various stage compressors, through the burner cans, through the hot section turbine blades and out the exhaust at the rear. The hot section turbine blades, in turn, power the compressor stages and the front fan. I don't know about anyone else, but, as I see it and knowing turbine engines as well as I do, without having negative pressure in front of and inside of the engine inlet when that engine is running, THAT ENGINE WON'T BE RUNNING AT ALL, REGARDLESS OF ALTITUDE OR SPEED
07-27-2016, 12:38 PM
#3527
Hey guys U may be Hanging an Innocent man. If U google maps JFK and measure a line 4 miles in length from the approach end of RW 13L then back to the geographical center of JFK I come up with a total of 9.19 Statute Miles and Air craft report in NM so it would be even farther out. So using 9.19 total SM minus 4.0 SM that puts this guy .19 SM out side of the 5 mile radius around JFK. This might makes him legal, Not smart but Legal just the same.
https://www.google.com/maps/place/Jo....7781391?hl=en
https://www.google.com/maps/place/Jo....7781391?hl=en
07-27-2016, 12:42 PM
#3528
That's borderline math right there...I'm out !
But...paper said 4 miles, didn't get more specific. Then again it also said he was 1100 feet above the runway...how could he have done that if he was 4 miles away.
Keep in mind...this is the NY POST...one step above National Inquirer.
But...paper said 4 miles, didn't get more specific. Then again it also said he was 1100 feet above the runway...how could he have done that if he was 4 miles away.
Keep in mind...this is the NY POST...one step above National Inquirer.
4NM from the runway threshold. Aircraft normally report their position, when on approach, as the distance to the approach end of the runway. Now goto Google Maps, insert JFK then right click on the approach end of the NW West most runway. It has a lart 13L painted. Then click Measure distance. now drag the map our 4 miles til U are just south of Forest Park and click the mouse and drag the dot till the panel says U are 4 miles from your first mark. then go back to JFK and Click on the dot under the Upside down Teardrop. Read approximately 9.19 miles total minus 4 miles and that puts him just over 5 miles from the airport. He may be legal a judge will decide. Whana bet he was flying at forest park?
07-27-2016, 01:04 PM
#3529
That's borderline math right there...I'm out !
But...paper said 4 miles, didn't get more specific. Then again it also said he was 1100 feet above the runway...how could he have done that if he was 4 miles away.
Keep in mind...this is the NY POST...one step above National Inquirer.
But...paper said 4 miles, didn't get more specific. Then again it also said he was 1100 feet above the runway...how could he have done that if he was 4 miles away.
Keep in mind...this is the NY POST...one step above National Inquirer.
If U look at the profile for the 13l Ils at JFK the glide slop is 3 degrees but if he was cleared for a Visual Approach he could have been using the VASI (Visual Approch Slop Indicator) wich is 2.75 degrees not 3.00 degrees that the Glide Slope has. Now on the Glide solp at the FAF (Final Approach Fix) 4.5 NM from the runway threshold is 1500' MSL or 1488' Above the Runway.
ILS13L at JFK
http://flightaware.com/resources/airport/JFK/IAP/ILS+OR+LOC+RWY+13L/pdf
07-27-2016, 07:10 PM
#3533
If the engine cannot work with positive pressure at the intake, then how in the world do RAM jets work? The engine will pull even more air in if there is positive pressure. If the turbine was not working then that positive pressure would be even higher. As I said the positive pressure is slight. Without the engine running it would be very high, enough to blow you mouth open and pop out your eyeballs I suppose.
A ram jet, on the other hand, is not even in this discussion because it requires forward motion to supply the air needed to burn fuel, working more like a rocket engine. Instead of using a compressor system to pack in air, a ram jet uses a narrowing of the inside of the tube, a reduction of volume to force the air into the combustion area under pressure. It then, like a rocket, uses the pressurized air to burn the fuel and expels the hot exhaust out the rear, providing thrust. As a result, a ram jet uses no moving parts other than a fuel control to operate. It also, however, requires the aircraft to already be at a speed high enough to supply the required air to operate. Thus, in the world of jet powered airliners, a ramjet isn't an option since it's not self starting or sustaining on the ground nor is it fuel efficient enough to be cost effective to operate as a thrust source to maintain airspeed.
Once again, you've tried to twist the truth and, like normal, your argument not only has no merit, it has no facts or logic to back it
Last edited by Hydro Junkie; 07-27-2016 at 07:14 PM.
07-28-2016, 03:23 AM
#3536
Positive pressure is in excess of 14.7 lbs at sea level, lower as you get higher in the atmosphere. With a turbine engine running, the pressure goes negative because the stage one fan pulls air into the engine, leaving no air in front of the fan. More air then has to fill the void before being sucked through as well. This, obviously, means that there is always going to be negative pressure in front of an engine, regardless how high or fast that engine is running.
A ram jet, on the other hand, is not even in this discussion because it requires forward motion to supply the air needed to burn fuel, working more like a rocket engine. Instead of using a compressor system to pack in air, a ram jet uses a narrowing of the inside of the tube, a reduction of volume to force the air into the combustion area under pressure. It then, like a rocket, uses the pressurized air to burn the fuel and expels the hot exhaust out the rear, providing thrust. As a result, a ram jet uses no moving parts other than a fuel control to operate. It also, however, requires the aircraft to already be at a speed high enough to supply the required air to operate. Thus, in the world of jet powered airliners, a ramjet isn't an option since it's not self starting or sustaining on the ground nor is it fuel efficient enough to be cost effective to operate as a thrust source to maintain airspeed.
Once again, you've tried to twist the truth and, like normal, your argument not only has no merit, it has no facts or logic to back it
A ram jet, on the other hand, is not even in this discussion because it requires forward motion to supply the air needed to burn fuel, working more like a rocket engine. Instead of using a compressor system to pack in air, a ram jet uses a narrowing of the inside of the tube, a reduction of volume to force the air into the combustion area under pressure. It then, like a rocket, uses the pressurized air to burn the fuel and expels the hot exhaust out the rear, providing thrust. As a result, a ram jet uses no moving parts other than a fuel control to operate. It also, however, requires the aircraft to already be at a speed high enough to supply the required air to operate. Thus, in the world of jet powered airliners, a ramjet isn't an option since it's not self starting or sustaining on the ground nor is it fuel efficient enough to be cost effective to operate as a thrust source to maintain airspeed.
Once again, you've tried to twist the truth and, like normal, your argument not only has no merit, it has no facts or logic to back it
The plane was on approach so the engine was lilkely just over idle, so it would have had positive pressure at the engine from the airspeed, you know the pressure that makes pitot tubes work. No way it would be at negative pressure on approach, so no suction. The same forward motion that makes a ram jet engine is the same forward motion that causes positive pressure on a jet engine. As I said it is not at positive pressure when under full power such as in a climb, but low powered cruise it may have slightly positive or negative pressure.
07-28-2016, 03:26 AM
#3537
Porcia, that was on the ground. I never said there is not suction when on the ground, but in the air the airspeed provides pressure, when in landing mode it would be positive and there would be no suction to anything but the air already in the nacelle.
07-28-2016, 03:46 AM
#3538
This is correct as it was presented in A&P training and was always referred to as "negative pressure" , I gotta admit I wondered why it wasn't just called Vacuum instead ? And yes , it's that negative pressure that's responsible for all kinds of things getting sucked in at inopportune moments , small stones , other debris , and sometimes the occasional person ........
It's the same as, is a wings lift created by the Lower Pressure on the top or the Atmospheric on the under side. (I still say it's all to do with Angle of Attack) else how does that same wing fly upside down?.It ain't SUCTION baby.
It's sorta like the sun is coming out. NO the clouds are dissipating or moving out of the way . The sun was always there. For the Smart A** that says not at Night. Yes it's true just on the other half of the planet. What thread is this anyway?
07-28-2016, 04:14 AM
#3540
Banned
My Feedback: (8)
yes, it was on the ground...and it was posted in response to Init's comments right before mine about things being sucked in at inopportune times, even people. I didn't comment on what you said or didn't say. But also all this talk about sucking and positive pressure etc is getting well, a bit tawdry. I'm getting the vapors.
07-28-2016, 06:21 AM
#3544
Sucked in or better yet PUSHED in by the Slandered (Atmospheric) pressure rushing in to fill the VACUUM or the area of LOW pressure created by the engine it's self.That's until we get in the realm of comprehensibility of course.
It's the same as, is a wings lift created by the Lower Pressure on the top or the Atmospheric on the under side. (I still say it's all to do with Angle of Attack) else how does that same wing fly upside down?.It ain't SUCTION baby.
It's sorta like the sun is coming out. NO the clouds are dissipating or moving out of the way . The sun was always there. For the Smart A** that says not at Night. Yes it's true just on the other half of the planet. What thread is this anyway?
It's the same as, is a wings lift created by the Lower Pressure on the top or the Atmospheric on the under side. (I still say it's all to do with Angle of Attack) else how does that same wing fly upside down?.It ain't SUCTION baby.
It's sorta like the sun is coming out. NO the clouds are dissipating or moving out of the way . The sun was always there. For the Smart A** that says not at Night. Yes it's true just on the other half of the planet. What thread is this anyway?
07-28-2016, 06:29 AM
#3545
I beg to differ again. For a turbine engine to work AT ALL, it is constantly pulling air into the front fan. There is no way for it to pull air into said fan and not have negative pressure AT ALL TIMES!!!!!!!!!!!!!!!!!!!!!!! Roughly 80% of the air pulled through the fan goes around the engine, creating an equal percentage of thrust. The other 20% goes through the various stage compressors, through the burner cans, through the hot section turbine blades and out the exhaust at the rear. The hot section turbine blades, in turn, power the compressor stages and the front fan. I don't know about anyone else, but, as I see it and knowing turbine engines as well as I do, without having negative pressure in front of and inside of the engine inlet when that engine is running, THAT ENGINE WON'T BE RUNNING AT ALL, REGARDLESS OF ALTITUDE OR SPEED
07-28-2016, 07:04 AM
#3546
It was very windy on the way home last night and as I drove by a dumpster I noticed that he lid was up at about a 30 degree angle and bouncing a little with the wind gust. The wind was blowing over the top of the lid from the hinge to the non-hinge side. Obviously the wind was creating a low pressure above the dumpster and suction was pulling the lid up. Angle of attack had nothing to do with it since there was no way the wind was getting underneath the lid.
Ber·noul·li's prin·ci·plenoun
- the principle in hydrodynamics that an increase in the velocity of a stream of fluid results in a decrease in pressure. Also called Bernoulli effect or Bernoulli theorem.
But it could have been a couple of Alley Cats fighting some ones discarded Sandwich. LOL
07-28-2016, 07:05 AM
#3547
You guy's are not getting it. Let's look at this as velocity instead of pressure. I do not know what the jet exhaust speed is typically when the engine is idling, but I bet it is a lot less than approach speed. And the intake velocity is less because of the larger intake area. So if the plane is on approach at say 160 MPH and near idle with an exhaust velocity of 100 MPH and the intake velocity less than that then the air flow is going to be rammed into the jet intake and flow out and around it. So the engine cannot be sucking stuff in except for that which is right in front of the engine.
07-28-2016, 07:07 AM
#3548
No such thing as "SUCTION" it's all about the difference in air Pressure. I believe atmospheric Pressure in the dumpster would be higher than the reduced air pressure 0n the upper surface of the dumpster lid. The resulting difference in the two pressurizers caused the lid to raise. I believe it's called
Ber·noul·li's prin·ci·plenoun
But it could have been a couple of Alley Cats fighting some ones discarded Sandwich. LOL
Ber·noul·li's prin·ci·plenoun
- the principle in hydrodynamics that an increase in the velocity of a stream of fluid results in a decrease in pressure. Also called Bernoulli effect or Bernoulli theorem.
But it could have been a couple of Alley Cats fighting some ones discarded Sandwich. LOL
07-28-2016, 07:14 AM
#3549
Now where ya go ta High School. Didn't ya take Freshman General Science. I was told that because of lower Pressure, things were PUSHED in to the low pressure area.
According to the ancient philosopher Aristotle, “Nature abhors a vacuum.” Aristotle based his conclusion on the observation that nature requires every space to be filled with something, even if that something is colorless, odorless air..