Dubai, Why are plane windows round?
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We often learn the most from our failures, this is particularly true for advancements in the field of engineering. Unfortunately for the engineers in the aviation industry, the prices to pay for failure are high. This will be a reoccurring theme in my videos, trust me. The flip-side of this unforgiving industry, is that it consistently provides learning opportunities for engineers, because failure is not an option when peoples lives are at risk. One of the greatest examples of this occurred during the development of cabin pressurisation. The problems caused by cabin pressurisation didn’t develop until the introduction of the first commercial jet powered aircraft, The De Havilland Comet. It entered service in 1952 and initially proved to be a massive success, but just one year into service catastrophe struck. Three Comets suffered fatal mid-flight disintegrations and the entire fleet was grounded until the cause was identified. The root of the problem was double-edged. The introduction of jet engines required planes to fly even higher in order to make the fuel hungry engines economically viable (less drag in the upper atmosphere means less fuel is needed). As a plane increases in altitude the external atmospheric pressure lowers to a greater extent than the internal cabin pressure. This creates a pressure differential that causes the fuselage to expand ever so slightly. Engineers accounted for this, but the effects of repeated pressure cycles over time were not well known at the time. Over thousands of cycles and metal begins to fatigue and cracks can form at high stress locations. The effects of stress concentration were also not well understood at the time. Stress concentration occurs when the flow of stress is interrupted. Square windows, in contrast to modern oval windows, provide a significant barrier to the smooth flow of stress. Because of this stress peaks at the sharp corner of the window, and this is exactly where investigators determined the origin of failure to be. These combined phenomenon proved to be fatal. Today all airliners feature oval windows to avoid this stress concentration and comprehensive fatigue testing is required before a plane can be approved by the FAA. We often learn the most from our failures, this is particularly true for advancements in the field of engineering. These are now two basic concepts that every materials engineer is taught, these events allowed us to further our understanding of materials and prevent further failures. For licensing rights contact me at mcmanusbrian15@gmail.com
Comments
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Know why planes have round Windows? BECAUSE THEY WANT TO!!!!
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the rounded edges help the window from cracking at high altitude
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That red lines, are they what the engineers call shear flow?
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That was quite interesting, thanks for the upload !
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Sorry but you're wrong. It's the window OPENING that carries the load and the window opening has the soft smooth corners. The opening itself is reinforced with thicker fuselage skin and internal bonded doublers to carry the fuselage loads around the opening. The window itself is a plug in the opening. Does it carry some loads? Yes, but the bolts that hold the window plug are long, and are actually only designed to hold the window correctly in the opening. So very little of the fuselage load that is in the skin is actually carried through the window itself. I know this, I've repaired scores of corroded window openings on older B747's. Most of this kind of math and design is not taught or learned in college. You have to be a good maintenance engineer on the shop floor where you learn this kind of stuff.
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Let me guessHe's gonna talk about the de hav
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Stress concentration also occurred around the square hatches of Liberty ships, causing them to break up at sea.
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This is what my engineering analysis professor worked on apparently. Professor Ronald Bagley. At least he talked about this investigation when I was in his class(he's retired now). He also always talked about the "equation named after him." It's a pretty obscure equation that most people won't come across unless you know what viscoelasticity is, but it's interesting. It has to do with fractional differential equations, which is a hard concept to wrap your mind around. Anyway... he wasn't very good at teaching. Perhaps a great mind, but not a great teacher.
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more than amazing
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Wow. Simply amazing. Keep up the great work man.
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In one day you gained 6,000 subs. Great work man!
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You should make a video why some airplanes have the wings attached to the top of the cabin and others have it attached to the bottom.
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becasue that is appropriated shape lol
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Been looking for more informative channels out there. Ofc i failed, but thanks to yt i found this in recommended.
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There using a Boing 707-300 maybe 707-200 in the demo at the start of the video
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Bush did 9/11 and Trump knows
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umm sorry? but I've been working with private jet and most of them are sphere shape instead of rectangle shape.
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Nicee
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I was on a plane a week ago and the widows weren't oval none are the problem with the comet was that the window didn't have round edges that is why newer planes have rounded out edges on the squarer windows
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