Physics
Aeroacoustic Noise Prediction in Turbofan Engine Nacelles
Quick fact
The fan noise inside a turbofan nacelle is often the dominant noise source during takeoff, and even small changes in blade shape can change noise levels by several decibels, which is huge because the decibel scale is logarithmic.
Why this is interesting
Every time a jet takes off, a roar thunders across the airport — but that roar is not just jet exhaust; it's a symphony of sound sources, and predicting it is one of the hardest challenges in engineering. How do engineers know how loud an engine will be before it's even built?