Summary: | 碩士 === 國立臺灣大學 === 電機工程學系 === 86 === In this thesis,we will propose a method,the 2.5D SBR-image method,
to simulate sound wave propagation in a large empty room.First,we
simplify a 3D problem into a 2D one by initially neglecting the
third dimension.Then,we shoot 2D ray tubes from a sound source until
it hits a wall which we assume to be a rigid wall in most cases for
simplicity.In accordance with the law of reflection,we can trace the
ray tube in its new direction towards the next wall.In every bounce,
we have to examine if the receiver falls within the ray tube.Once it
does,an exact 2D ray path is determined and we consider the effect of
the third dimension at the same time.Finally,we calculate the field
due to the correspondent image along the real 3D ray path.This procedure
repeated until all of the ray tubes have been traced.By superposition,
we are able to calculate the contribution of every equivalent sound
source individually.Compared with the original 3D SBR-image method,
2.5D SBR-image method is more efficient and time-saving.By this method,
we computed the distribution of sound pressure in different kinds of
buildings.The results are rather satisfactory.
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