Radiated sound using topology optimization

JGU

Hi. 

 

I'm studying radiation sound topology optimization, and my optimization object enclosed in far-field(air).

 

Radiation sound topology optimization resulted in the reduction of the volume fraction (like picture).

 

But I have a question.

 

When the topology is optimized, a empty space (no-mesh space) is created between the constructed Far-Field and the object.

 

But I wonder how the topology optimization works.

 

Does radiation sound not transmit to empty space??

 

The picture below is the optimization result and I hide the far-field ( the object is surrounding in sphere far-field)

 

I'm appreciate in advance. /emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />