One of the main criteria determining thermal comfort of occupants is the air temperature that needs to be adjusted effectively. For this purpose, the air temperature distribution of the whole space must be determined. In conventional methods, thermistors are largely applied by mounting them physically in separate locations of the indoor environment. However, they provide the local temperature instead of the temperature distribution in the whole room including the occupant zone. Moreover, the thermistors have contact with the measurement environment thus they might affect the temperature and flow by their own existence.

It therefore would be effective development of a new measuring method that can overcome the mentioned shortcoming of the conventional sensors. In this regard, the acoustic travel-time tomography (ATOM) is considered as a solution. By using the ATOM technique, not only many more data points per sensor can be generated but also non-contact and non-destructive measurements are provided.

In principle, the ATOM technique utilizes the dependency of the speed of sound on air temperature and flow velocity in the medium. The average speed of sound, along the propagation paths, can be determined by travel-time estimation of a defined acoustic signal between transducers. For discretization of the temperature, the tomographic domain is divided into volumetric grid cells called voxels. Subsequently, the spatial distribution of temperature within each voxel can be determined by applying a proper tomographic reconstruction algorithm

In this project, the acoustic travel-time tomography will be developed to obtain the non-invasive thermal distribution of a room with an ability of measuring a rapid change in temperature. Subsequently, the ATOM temperatures can be used as the input data for the thermal comfort analysis of an office.

Funded by: 
Thüringer Graduiertenförderung 

Project duration:
04/2018 - 03/2021

Contact person:
Najmeh Sadat Dokhanchi M.Sc.
Tel. +49(0)36 43/58 44 59