Search found 66 matches

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by aeroguy
Fri Dec 15, 2006 4:58 am
Forum: Technical/Operations
Topic: Speed At Fanblade Tip?
Replies: 16
Views: 6105

RE: Speed At Fanblade Tip?

Some additional info in this previous thread on engine noise:
https://www.airliners.net/discussions/tech_ops/read.main/86105/

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by aeroguy
Tue Dec 12, 2006 5:03 am
Forum: Civil Aviation
Topic: 747 LCF No Winglets?
Replies: 35
Views: 8187

RE: 747 LCF No Winglets?

<TABLE BORDER=0 ALIGN=CENTER WIDTH=95% style="border-top: 1pt #28455E solid;border-right: 1pt #1B2E3F solid;border-bottom: 1pt #1B2E3F solid;border-left: 1pt #28455E solid;table-layout:fixed;border-spacing:0;padding:0;border-collapse: collapse;" bgcolor=#1E3951><tr><td><font size=2 face="ARIAL, Helv...

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by aeroguy
Sun Sep 17, 2006 1:23 pm
Forum: Civil Aviation
Topic: 747LCF Arriving At BFI ~8am Saturday 9/16...
Replies: 27
Views: 6099

RE: 747LCF Arriving At BFI ~8am Saturday 9/16...

Yeah definitely seemed like a good crowd this morning. I was at the southeast end, over on Airport Way South with a nice angle looking almost straight up 31L. Only problem is that it's a little far away from aircraft that are landing on 13R. I'd post my pictures but they only look good zoomed in on ...

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by aeroguy
Thu Nov 03, 2005 12:30 pm
Forum: Military Aviation & Space Flight
Topic: Sound Barrier
Replies: 34
Views: 8373

RE: Sound Barrier

Vzlet, the inlets on the F-8 and the Saab you have there are normal shock type inlets. (In reality, the F-16 you show actually has a normal shock type inlet as well). Normal shock inlets have a normal shock that sits at the mouth of the inlet during supersonic flight. (It can also become detached bu...

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by aeroguy
Tue Oct 11, 2005 11:05 am
Forum: Civil Aviation
Topic: Abcnews. Photo Of The Week
Replies: 14
Views: 11266

RE: Abcnews. Photo Of The Week

Yep, AS739X and PlainSmart hit the nail on the head. The media has been reading too many <acronym title="British International Helicopters">BS</acronym> websites or something. A plane doesn't necessarily need to be supersonic to have that vapor cloud form. This was discussed just last week over in t...

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by aeroguy
Thu Oct 06, 2005 12:01 pm
Forum: Military Aviation & Space Flight
Topic: Sound Barrier
Replies: 34
Views: 8373

RE: Sound Barrier

If you have not seen this site yet, it has an excellent description of what is happening here (i.e. just because you see some vapor, that doesn't mean the plane is supersonic): <a href="http://www.fluidmech.net/tutorials/sonic/prandtl-glauert-clouds.htm" target=_blank>http://www.fluidmech.net/tutori...

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by aeroguy
Fri Sep 30, 2005 11:53 am
Forum: Technical/Operations
Topic: A320 Nose Gear Incidents
Replies: 32
Views: 8635

RE: A320 Nose Gear Incidents

OK so just to recap here a bit for the benefit of my understanding since there have been quite a few posts in several different threads... It would appear that the A320 does have a nose wheel centering cam and the incidents in which the gear was turned 90 degrees were not an intentional computer com...

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by aeroguy
Sun Sep 25, 2005 10:43 pm
Forum: Military Aviation & Space Flight
Topic: Did Nasa Put Men On The Moon?
Replies: 68
Views: 9826

RE: Did Nasa Put Men On The Moon?

Here's a website that I've always thought was a good read:

http://www.badastronomy.com/bad/tv/foxapollo.html

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by aeroguy
Sat May 14, 2005 12:32 pm
Forum: Technical/Operations
Topic: Fuel Vaporization/Combustion- Confused
Replies: 7
Views: 7810

RE: Fuel Vaporization/Combustion- Confused

In line with what Air2gxs and Prebennorholm said, I'd also add a few things. Just to make sure everyone is clear: <b>Atomization</b>: process by which a liquid is broken into tiny droplets and mixed with air. <b>Vaporization</b>: evaporation of a liquid to a gas state. In a non-premixed combustion s...

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by aeroguy
Thu Apr 28, 2005 7:10 am
Forum: Technical/Operations
Topic: What Is A Dual Annular Combustor?
Replies: 13
Views: 20807

RE: What Is A Dual Annular Combustor?

Perhaps the end of this thread might be helpful as well: <i><a href="/discussions/tech_ops/read.main/84221/" target=_blank>777 GE-90 "dome" Combustion</a></i> <font size=1>(by <a href="/discussions/profile.main?username=QANTAS747-438" class=quote target=_blank>QANTAS747-438</a> Mar 22 2004...

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by aeroguy
Sat Apr 10, 2004 2:19 am
Forum: Technical/Operations
Topic: Gas Turbine Engine Noise
Replies: 8
Views: 6843

RE: Gas Turbine Engine Noise

You can definitely have supersonic flow in a jet engine. As was mentioned the fan is the most obvious place. With the steady trend of increasing bypass ratio, tip speeds have gone supersonic. It seems logical that you wouldn't want a supersonic fan but it's a reality of modern fan design and actuall...

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by aeroguy
Thu Mar 25, 2004 1:28 pm
Forum: Technical/Operations
Topic: 777 GE-90 "dome" Combustion
Replies: 5
Views: 12142

RE: 777 GE-90 "dome" Combustion

I think the way to look at the dual annular combustor might be to consider the conflicting design requirements of low NOx emissions and low CO & unburned HC (Hydrocarbon) emissions. For example, decreasing flame temperature improves NOx emissions but makes CO and HC worse. Decreased residence time r...

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by aeroguy
Fri Mar 12, 2004 2:41 am
Forum: Military Aviation & Space Flight
Topic: F-35 In Trouble Already?
Replies: 27
Views: 5885

RE: F-35 In Trouble Already?

Can anyone say F-111? I'm with garnetpalmetto, from the beginning I have been skeptical of combining so much into one aircraft. I know some people that are very optimistic about it though. Frankly the F-35 is going to have to be one heck of an impressive airplane if it's going to do all the things t...

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by aeroguy
Wed Mar 03, 2004 2:22 am
Forum: Military Aviation & Space Flight
Topic: F-14 Tomcat
Replies: 22
Views: 6923

RE: F-14 Tomcat

I think it would have been interesting if instead of the Super Hornet program, the Navy had undertaken a "Super Tomcat" program. Don't get me wrong, the F-14D is quite capable, but I think another leap forward from there would have made for an awesome airplane. Would have been neat to see the result...

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by aeroguy
Tue Feb 24, 2004 7:36 am
Forum: Military Aviation & Space Flight
Topic: Army Kills Comanche
Replies: 31
Views: 4317

RE: Army Kills Comanche

I think the fact the Army went through multiple revisions of Comanche's mission was a bit of a sign that either they didn't know what they wanted or the mission it was originally intended for was no longer around. A little of both maybe, leaning more towards the latter? I was always confused whether...

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by aeroguy
Thu Feb 19, 2004 2:34 am
Forum: Civil Aviation
Topic: New UAL Paint - Harsh Comments
Replies: 61
Views: 9814

RE: New UAL Paint - Harsh Comments

Does anyone remember back to when the current gray and blue livery was unveiled? Those were the good old days I guess. That really was nice to see United come up with something unique like that. As an aside, congrats to USAirways! Thanks to United's and Northwest's recent livery changes (pronounced ...

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by aeroguy
Fri Jul 25, 2003 1:54 am
Forum: Civil Aviation
Topic: Which United Airlines Livery Is The Best?
Replies: 25
Views: 14056

RE: Which United Airlines Livery Is The Best?

Futureualpilot hit it right on the head. In my opinion UAL's planes look great in their current livery. I think both UAL and USAirways have proven that a dark color scheme can look very good if done right. Dark is too boring for some of you I suppose. The all-pervasive Euro-white is not boring? How ...

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by aeroguy
Sat Mar 01, 2003 3:17 am
Forum: Technical/Operations
Topic: Adverse-yawing Moment At High Speeds
Replies: 5
Views: 3912

RE: Adverse-yawing Moment At High Speeds

I sort of hope your professor didn't explain adverse yaw by saying the wings have different angles of attack. Consider the lift generated by the wings in a left roll. The right aileron is deflected down, the left is deflected up. The extra lift generated by the right wing due to the aileron deflecti...

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by aeroguy
Mon Feb 17, 2003 12:31 am
Forum: Military Aviation & Space Flight
Topic: Lockheeed SR71 Inlets
Replies: 8
Views: 6128

RE: Lockheeed SR71 Inlets

I would agree that thrust is actually created by the inlets. I would also agree that it is counter-intuitive. I had to write out the momentum equation to convince myself that it was actually true. Odd as it may sound, during diffusion in the inlet, the fluid exerts a force in the forward direction o...

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by aeroguy
Sun Feb 16, 2003 11:42 pm
Forum: Technical/Operations
Topic: Reverse Thrust Capability
Replies: 16
Views: 3858

RE: Reverse Thrust Capability

This may be a minor detail but the flow does not necessarily need to be "reversed" by a thrust reverser in order to create reverse thrust. If you design a machine that takes flow in from the front and exhausts it out the side, the net thrust this machine produces would be in the backward direction. ...

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by aeroguy
Fri Feb 14, 2003 2:51 am
Forum: Technical/Operations
Topic: Boeing WIG
Replies: 8
Views: 2868

RE: Boeing WIG

Here's a little info:
http://www.popsci.com/popsci/aviation/article/0,12543,410266,00.html

[Edited 2003-02-13 18:53:24]

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by aeroguy
Sun Jan 26, 2003 1:04 pm
Forum: Military Aviation & Space Flight
Topic: B52 Flight Characteristics
Replies: 13
Views: 12481

RE: B52 Flight Characteristics

The reason the B-52 wing is configured with positive incidence relative to the fuselage has to do with takeoff performance and can be traced all the way back to its bombs. For those of you who were concerned about the "G-Jump" when the bombs are dropped, I would propose that the bigger worry would b...

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by aeroguy
Sun Dec 08, 2002 11:27 pm
Forum: Technical/Operations
Topic: 3-D Aero Technology (GE90)
Replies: 5
Views: 3863

RE: 3-D Aero Technology (GE90)

I'm not really sure of a good way to describe what 3D Aero technology is but I'll give it a shot. Simply put, 3D Aero implies that 3D Computational Fluid Dynamics was used in the design. That doesn't sound like much and granted, CFD remains more of an art than a science, but engineers still possess ...

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by aeroguy
Tue Nov 12, 2002 11:07 am
Forum: Civil Aviation
Topic: Anybody Want To Live In A 727?
Replies: 13
Views: 3644

Anybody Want To Live In A 727?

I'm really not sure what to say about this. It has to be seen to be believed I guess...

http://www.airplanehomes.com/

http://maxpoweraero.com/homes/pageone.htm

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by aeroguy
Thu Oct 31, 2002 8:12 am
Forum: Civil Aviation
Topic: Airbus Full Of Themselves?
Replies: 25
Views: 2449

RE: Airbus Full Of Themselves?

I don't know how many people have been following, but Airbus used to have more detailed order and delivery info on their website. Unlike Boeing's website, on Airbus' website you can only get info from the current year. So to answer the A320 sales history question wouldn't it be nice if Airbus would ...

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by aeroguy
Wed Oct 30, 2002 10:03 pm
Forum: Technical/Operations
Topic: The Latest GE90 On It's 747 Test Bed.
Replies: 16
Views: 6295

RE: The Latest GE90 On It's 747 Test Bed.

I haven't heard of anyone working on a variable pitch fan either. I'm not sure if it really gets you anything besides a big headache. A variable pitch fan would be more helpful in matching different altitude conditions but I think the effect is minimal, especially considering the increased complexit...

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by aeroguy
Sun Oct 20, 2002 9:19 am
Forum: Military Aviation & Space Flight
Topic: Shaw Fest This Weekend In SC
Replies: 2
Views: 3075

RE: Shaw Fest This Weekend In SC

I went and was pretty impressed with what they had to offer. I didn't get there too early, about when the Apaches and Blackhawk were flying. I suppose I got there too late to see the performance of the Starfighters. I saw them parked on the ramp, that's about it. I thought the Thunderbirds put on a ...

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by aeroguy
Wed Sep 04, 2002 1:56 am
Forum: Technical/Operations
Topic: The Most Lift On A Wing
Replies: 6
Views: 4727

RE: The Most Lift On A Wing

Put simply, no. With an elliptical lift distribution, the maximum lift is at the wing root. Everywhere else along the span (including near the engines and the tip), the lift will be less than at the root. Why all this talk about elliptical lift distribution? Ideally, you want as close to an elliptic...

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by aeroguy
Thu Aug 01, 2002 1:44 am
Forum: Technical/Operations
Topic: Inboard Versus Outboard Ailerons
Replies: 5
Views: 16282

RE: Inboard Versus Outboard Ailerons

To add a little more detail to the discussion, I think someone should mention the aeroelastic reasons for having two sets of ailerons. The big problem with ailerons out at the tips of long flexible wings is aileron reversal at high speed. Let's say there is airliner flying pretty fast and the pilot ...

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by aeroguy
Fri May 31, 2002 8:06 am
Forum: Technical/Operations
Topic: Variable Pitch For Jet?
Replies: 12
Views: 4145

RE: Variable Pitch For Jet?

Yeah, variable pitch stators and inlet guide vanes are one thing, variable pitch fan (rotor) blades are a whole other story. Does anyone have any information about who might be working on variable pitch fan blades? I can't imagine the extra mechanical complexity is worth any increase in efficiency. ...

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by aeroguy
Fri Mar 29, 2002 12:05 am
Forum: Technical/Operations
Topic: Jet Engine, Exhaust Air Velocity?
Replies: 17
Views: 50039

RE: Jet Engine, Exhaust Air Velocity?

I'd have to disagree that engines cannot accelerate air to supersonic speeds. Afterburning engines certainly accelerate the exhaust gases to supersonic speeds. This occurs despite the fact that the speed of sound of the exhaust gases has increased due to the high temperature. By considering an after...

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by aeroguy
Mon Mar 18, 2002 5:57 am
Forum: Technical/Operations
Topic: 777 Powere Plant Transportation
Replies: 13
Views: 2481

RE: 777 Powere Plant Transportation

I don't know about P&W or RR, but the GE90 is designed so that the fan module is <i>relatively</i> easy to remove from the core engine for transport. With the engine split into two pieces, it can be transported on widebody freighters such as the A300F, MD-11F, 747F, etc. The fan module is placed on ...

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by aeroguy
Mon Mar 11, 2002 12:28 am
Forum: Technical/Operations
Topic: Slats, How They Work?
Replies: 27
Views: 8604

RE: Slats, How They Work?

People tend to use the terminology pretty freely, probably because they're not sure what any of it really means. Unfortunately it confuses the issue for everyone. Leading Edge Slot: a channel which permits air from under the wing to blow over the top surface of the wing - delays separation and stall...

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by aeroguy
Tue Feb 19, 2002 12:03 pm
Forum: Technical/Operations
Topic: Why Do Forward Swept Wings Make Fast Aircraft
Replies: 17
Views: 17480

RE: Why Do Forward Swept Wings Make Fast Aircraft

Forward Swept Wings offer the same high speed drag reduction as Aft Swept Wings. Sweep, whether forward or aft, reduces the local Mach Number of the flow over the wing. This means that a transonic aircraft can cruise faster before encountering significant wave drag. An FSW has the added benefit in s...

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by aeroguy
Tue Feb 05, 2002 11:46 am
Forum: Technical/Operations
Topic: What's The Smallest Turbine Engine?
Replies: 9
Views: 5274

RE: What's The Smallest Turbine Engine?

Williams International is also developing derivatives of the FJX-2 turbofan in the form of the TSX-1 turboshaft and TSX-2 turboprop. The TSX-2 is supposed to produce 500 shp and weigh 130 lbs. It will have a length of 41 inches and a diameter of 13.5 inches. I believe the TSX-2 is in ground tests, n...

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by aeroguy
Wed Jan 23, 2002 1:01 pm
Forum: Civil Aviation
Topic: 737 NG & IAE V2500
Replies: 26
Views: 6348

RE: 737 NG & IAE V2500

I'm pretty confused, so I thought I'd include all of you in on it. I too was under the impression that the V2500 was more fuel efficient than the CFM56. I was just looking in the Av Week Sourcebook and pulled some numbers. Here are thrust and TSFC (at max power) values: A319: V2522-A5 22000 .34 V252...

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by aeroguy
Sun Jan 20, 2002 1:21 am
Forum: Military Aviation & Space Flight
Topic: Just Saw "Black Hawk Down"
Replies: 17
Views: 3883

RE: Just Saw "Black Hawk Down"

Well said, Cx889! Black Hawk Down was excellent! Both the book and the movie that is! Reading the book, I was worried that hollywood would butcher the story when making the movie, but I was pleasantly surprised. They did a good job condensing a complicated story with lots of characters down to a 2.5...

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by aeroguy
Fri Jan 18, 2002 1:52 pm
Forum: Military Aviation & Space Flight
Topic: Afterburners
Replies: 6
Views: 1308

RE: Afterburners

The important distinction here is what speed are we talking about. The HSCT choice of a turbojet had to do with speed. Turbofans are generally more efficient than turbojets at subsonic speeds. Turbojets are more efficient at supersonic speeds. Most fighters and bombers spend most of their time in su...

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by aeroguy
Tue Jan 15, 2002 2:16 am
Forum: Military Aviation & Space Flight
Topic: Afterburners
Replies: 6
Views: 1308

RE: Afterburners

Oh and to answer the second part, yes modern fighters use augmented turbofans. From a component standpoint, I don't know if augmentors are more efficient than afterburners. I guess augmentors run cooler thanks to the injection of bypass air, but I don't know what that does to efficiency. Either way,...

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by aeroguy
Tue Jan 15, 2002 2:09 am
Forum: Military Aviation & Space Flight
Topic: Afterburners
Replies: 6
Views: 1308

RE: Afterburners

That's correct, the air in an afterburner or augmentor has been compressed already by the compressor. Consider what happens to the air pressure after the compressor: There is a small amount of pressure loss through the combustor. Then the air is expanded through the turbine, (obviously) to a pressur...

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by aeroguy
Fri Dec 28, 2001 5:37 am
Forum: Technical/Operations
Topic: Need Help With Lift/drag Coefficients +AoA
Replies: 7
Views: 17358

RE: Need Help With Lift/drag Coefficients +AoA

Those values I mentioned for Cd0 from Raymer were from a section where he was taking about cruise, so I'll make the bold assumption that those numbers are for cruise. I might be wrong, but I'd assume that Cd0 values for landing and takeoff would not be too much different. The reason I'm curious is t...

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by aeroguy
Thu Dec 27, 2001 2:11 am
Forum: Technical/Operations
Topic: Need Help With Lift/drag Coefficients +AoA
Replies: 7
Views: 17358

RE: Need Help With Lift/drag Coefficients +AoA

Ikarus, I'm not sure I understand your zero lift drag coefficient (Cd0) values. The two values you give for Cd0 are .0963 and .1115, correct? In Raymer's design book, he quotes typical Cd0s of .015 (jet aircraft), .02 (propeller aircraft), and .03 (dirty, fixed gear prop aircraft). Also, I don't und...

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by aeroguy
Thu Dec 20, 2001 7:05 am
Forum: Civil Aviation
Topic: Comparing 777 Engines
Replies: 29
Views: 1803

RE: Comparing 777 Engines

If you look at the engines from the front, you can see that the GE90 and PW4000 fans both spin counterclockwise while the RR Trent spins clockwise. You can also identy the GE90 by the titanium leading edges on the composite fan blades.

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by aeroguy
Fri Nov 30, 2001 8:06 am
Forum: Technical/Operations
Topic: The GE-UDF Engine
Replies: 4
Views: 7398

RE: The GE-UDF Engine

Basically the concept was a high bypass unducted fan that was more fuel efficient and quieter than comparable turbofans. It was a pretty complex machine, the fan blades were mounted on separate spools that counter-rotated. The turbines were integrated into the hub of the fans and the two counter-rot...

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by aeroguy
Tue Nov 27, 2001 5:51 am
Forum: Military Aviation & Space Flight
Topic: TF-39
Replies: 7
Views: 2114

RE: TF-39

Here's a little more info for you B1C17L1011:

https://www.airliners.net/discussions/tech_ops/read.main/24002/5/

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by aeroguy
Tue Nov 27, 2001 5:34 am
Forum: Civil Aviation
Topic: What Is Boeing Thinking!?!
Replies: 48
Views: 3357

RE: What Is Boeing Thinking!?!

OO-AOG, I'm not sure I understand why you disagree with Wingman's facts. You may be able to argue with his speculation, but what is wrong with the facts that he stated? He makes some good points about A330/A340 loans and military subsidies, something that Airbus fans don't like to talk about much. I...

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by aeroguy
Thu Oct 25, 2001 10:55 am
Forum: Technical/Operations
Topic: RB211 Vs GE
Replies: 15
Views: 6516

RE: RB211 Vs GE

Does anyone have any more information about the recent incidents of uncontained failure on the CF6? How recent were they?

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by aeroguy
Sun Sep 30, 2001 5:49 am
Forum: Civil Aviation
Topic: Why Only GE 777LR?
Replies: 17
Views: 1376

RE: Why Only GE 777LR?

I read an article in Aviation Week that said both GE and P&W would only spend the development and certification costs to offer engines on the new 777LRs if they received exclusive contracts. They quoted a P&W VP who was essentially saying that they felt exclusivity was the only way that going after ...

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by aeroguy
Sun Sep 30, 2001 5:06 am
Forum: Civil Aviation
Topic: Jet Engines And The Noise They Make
Replies: 4
Views: 2507

RE: Jet Engines And The Noise They Make

I think you can classify gas turbine aircraft engine noise into two categories, internal and external. Internal noise is what comes from all the turbomachinery inside the engine. It's usually associated with the high pitched whine that you hear. I think the biggest source for internal noise on a hi...

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by aeroguy
Thu Sep 27, 2001 5:04 am
Forum: Technical/Operations
Topic: Temperature And Airspeed
Replies: 19
Views: 2920

RE: Temperature And Airspeed

OK, Victor Alpha, we may be on to something here. Can you give us a little more info? 1) When you cleared the weather and accelerated to M.84, and 496 knots GS, do you know what your IAS was? (It might help us figure this out) 2) When you talk about a mach number displayed on your instrument panel, ...

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