I do not wish to unnecessarily discredit someone based on my feeble knowledge of noise abatement, but I cannot imagine the flaps and demand pumps contribute in anything more than a miniscule way to the noise an aircraft makes.
The noise comes from the engines. Even the airflow over the flaps could not possibly compare to the noise generated by the engines.
As a simple example, I saw the space shuttle take off and land once in Florida. Take-off was noisy because of the engines. Landing was very quiet (apart from the two sonic booms!!), because it was gliding.
Am I missing something?
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