2 ms·
I remember C. Why did that stop? Are planes required to fly higher now, or did they get quieter?
by CobrastanJorji 7y ago
I remember C. Why did that stop? Are planes required to fly higher now, or did they get quieter?
- Obi_Juan_Kenobi 7y agoHigh-bypass turbofans, or just turbofans in general. In the early days of jet airliners, you had high-velocity exhaust providing all of the thrust. With turbofans, you have much more thrust coming from low-velocity bypass. This is quieter in itself, but also 'shrouds' the high-velocity exhaust. As bypass ratios get higher, engines generally get more efficient and quieter. The challenge in doing this is mostly engineering the large fans.
- corodra 7y agoOkay, then... am I crazy for noticing jet engines on airliners are significantly larger these days compared to 20 years ago? You did say larger fans. I always thought I was crazy when I noticed planes were quieter until Neil degrades Tyson mentioned it.
- travisjungroth 7y agoYou’re not crazy. The engines are bigger and quieter.
- tastygreenapple 7y agoDefinitely not crazy, and the engines are getting larger. The 737 MAX issues stem the packaging issues of putting larger engines on an airframe that wasn't really designed for them. The largest commercial jet engines are actually about as wide as the fuselage of the 737! The first jet engines were less than a meter wide.
- corodra 7y agoNeil degrades Tyson talked about this on the Joe Rogan show. Jet engines became more efficient and were mandated to be quieter. I'm not sure about altitude because I live near a major airport. Always have lived near airports. The general noise is flat out less.