Acoustic tomography of temperature and wind flow fields in a wind power plant

Measurement of indoor air temperature distribution using acoustic travel-time tomography: Optimization of transducers location and sound-ray coverage of the room

“…where ( ) is the spatially variable speed of sound, ( ) is the slowness which is a reciprocal value of the speed of sound, is the sound paths length, and describes the position inside the tomographic area as a vector of , and coordinates [11,3,4]. To extract the travel-time between the emitted and the received signal, the cross-correlating technique is used.…”

“…For discretization of the temperature and flow field, the tomographic domain is divided into volumetric grid cells called voxels. Subsequently, the spatial distribution of temperature and flow velocity within each voxel can be determined by applying a proper tomographic reconstruction algorithm [9,10,11,12,13]. The reconstruction of the air temperature distribution is a scalar tomographic problem, meaning that the scalar temperature influences the sound velocity independently of the direction of sound propagation [14,15,16,17].…”