General Questions

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On PC's, what is the name of the bar at the top of pages and folders? Not the one that contains File, Edit, and view, but the one that says the name of the page or folder you're viewing. What would the technical name be for that?
 
It's difficult to think of any more technical names than that! :dunce:
 
superberkut
Is the direction of rotation for a turbine still relevant on an aircraft? (i.e.: do you see, 'handed' turbofans?)
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Do you mean if the turbine spins one way then the Plane will go forwards and if the turbine spins the other way it will go backwards?
 
I know that would be a part of reverse thrust. So I guess not, then.

(I meant if the turbines on an aircraft were built to rotate in opposite directions to provide forward thrust, as propellers do. For instance, the de Havilland Mosquito has propellers that turn the same way, but the P-38 Lightning has, 'handed' propellers, which would rotate in opposite directions to counter propeller torque reactions.)
 
superberkut
I know that would be a part of reverse thrust. So I guess not, then.

(I meant if the turbines on an aircraft were built to rotate in opposite directions to provide forward thrust, as propellers do. For instance, the de Havilland Mosquito has propellers that turn the same way, but the P-38 Lightning has, 'handed' propellers, which would rotate in opposite directions to counter propeller torque reactions.)
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That first sentence isn't right, that's not how reverse thrust works. the engine doesn't change, there's a doohicky that goes into the exhaust stream to redirect the exhaust out and forward.

A turbine spinning backwards wouldn't run.

As for counter-rotating turbines, they don't do that, it would be incredibly expensive to have mirror-images of all those parts: compressor blades, turbine blades, etc. A jet's torque is minimal relative to the airframe anyway. A turboprop will have a more significant torque reaction with the propellor, but still, mfg costs mean all the same, engine-wise.
 
wfooshee
That first sentence isn't right, that's not how reverse thrust works. the engine doesn't change, there's a doohicky that goes into the exhaust stream to redirect the exhaust out and forward.
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Can you imagine the cost of high temp turbines before and after the combustion :yuck:
 
Here's a simplified schematic of a turbofan engine:

gas-turbine-turbofan2.gif


Clearly you can see that it is not symmetric front-to-back, so it will not work if the flow is reversed. This means that turbofan engines only produce thrust in 1 direction. A piece is placed in the exhaust stream to redirect it 180 degrees for reverse thrust.

In order for a turbofan engine to be able to rotate the other direction, the leading and trailing edges of each blade in the engine would have to be swapped either in the manufacturing process, or with an actuator inside the engine. Since these blades generally operate ABOVE the melting point of the metal in the blades, I imagine that the thermal considerations alone would be a major problem - let alone weight, reliability, power, etc. And for what benefit?
 
Wow I had to look at that twice then, for some reason it was weird seeing it going right to left.

Question, am I alone in being used to things "flowing" left to right.

For example, formulas are usually left to right, timelines, loading bars etc.
 
This goes left to right - rear to front. The direction the airplane would go would be left to right...
 
ExigeEvan
Wow I had to look at that twice then, for some reason it was weird seeing it going right to left.
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Hmmm, interesting. That seems like a natural orientation to me. It would be weird to see it headed the other direction. Do these images look strange to you?

just%20the%20car.JPG

Fig.8.gif

semmerlinglm4schematic.jpg


After doing some digging to find these, it appears (surprisingly to me) that it is more common for schematics to have the vehicle/device oriented right to left. I always think of it as having any motion headed to the right. So the car takes off to the right. The helicopter takes off to the right. And the gun fires to the right. Similarly the earlier jet engine takes off to the right. But perhaps that's not normal.
 
Danoff
After doing some digging to find these, it appears (surprisingly to me) that it is more common for schematics to have the vehicle/device oriented right to left. I always think of it as having any motion headed to the right. So the car takes off to the right. The helicopter takes off to the right. And the gun fires to the right. Similarly the earlier jet engine takes off to the right. But perhaps that's not normal.
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Blueprints are usually aligned right-to-left as well.

I'm still more used to stuff coming from the left and going right - the past three years of physics must've done that, since in most systems we're given in exams, the force, movement or acceleration goes left-to-right. Same with graphs..
 
Yeah again, I see jet engines more as the flow of air than as the movement of the engine itself. All of your images, Danoff, are normally orientated as I'd put it.
 
Actually, most books I read have blueprints or profiles orientated the oppoiste way from Danoff's pictures. They still look normal, though.

As for my statement, I wasn't thinking when I said it. While it is true that a turbine may rotate in the opposite direction, a reverse-thrust engine indeed has more components than a simple turbofan.
 
Being Grip is possibly the second most dull job in film-making, right after sandwich boy and right behind water-girl. You go somewhere, assemble a few tracks for the camera, build a few supports for equipment, then un-screw it after the day is over.
 
TB
Download version 8 and see if it still happens.
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Downloading now. I didn't know they had a free AVG 8, Every time I tried to download it said I had to buy it.

EDIT: Let's try this again, since my mom unplugged the power strip the modem and router was plugged into.
 
It took me a while to find the right one the first time, too.
 
Maybe. But probably by a pretty small percentage, since they still block the heat from entering the room completely. Would also depend on how effective your window glazing is, I guess.
 
niky
Maybe. But probably by a pretty small percentage, since they still block the heat from entering the room completely. Would also depend on how effective your window glazing is, I guess.
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I think you misread his question.

I know people around here put some sort of foil on their trailer windows for the sake of keeping heat out. I doubt black curtains would do much, but white should, theoretically. I don't think you'd be able to notice the difference though.
 
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