growl
Most likely the jet engines.
It is very rare to hear the sound of a propeller without the accompanying rumble of an engine as well. However, some newer aircraft are being equipped with very quiet engines, the Diamond Twin-Star for example has diesel engines which are very quiet indeed. The propellers themselves make a whirring sound much like you think they would, like the swoosh of a Baseball bat.
It is very rare to hear the sound of a propeller without the accompanying rumble of an engine as well. However, some newer aircraft are being equipped with very quiet engines, the Diamond Twin-Star for example has diesel engines which are very quiet indeed. The propellers themselves make a whirring sound much like you think they would, like the swoosh of a baseball bat.
the roar of the engines, or the vrooom!!!!!!!!!!!
They loose 66% of their power to heat and sound through friction. A Bugatti engine would make 3003 Bhp if there was no sound or heat loss due to friction.
the roar of the engines, or the vrooom!!!!!!!!!!!
Most diesel engines are turbodiesels, and the whistling is the sound of the turbo spooling up as it creates boost.
Many factories in Britain make jet engines.
Ships make many sounds. The sound of their engines is one of the most noticeable, but there are also sounds created by moving through water and interactions of various parts of the ship itself. Horns and bells may be used to signal.
They make all kinds of sounds. There'll be the sound of the engine... gas and diesel engines sound very distinct from each other... if the chassis isn't lubed, you'll hear squeaking, you'll hear squealing if the brakes aren't properly maintained, you'll have different exhaust tones with different aftermarket exhausts, etc.
Because there is no medium!