Particle Image Velocimetry measurement of indoor airflow field: A review of the technologies and applications

Quantifying the airflow field in building room or vehicle cabin indoor space is crucial for creating a thermal comfortable and healthy indoor environment. Airflow field measurement can provide quantitative information of indoor air distribution and local air velocity around occupants or passengers, which has strong relationship with the ventilation effectiveness, the pollutant transportation and the energy conservation in a building or a vehicle. However, the airflow field in indoor environment is normally characterized by high turbulent level and unsteady due to relatively low air velocity from the diffuser, thermal plume of heat source and unsteady perturbation of occupants’ behavior. Generally, it is very difficult to conduct accurate and detailed measurement of such a complex turbulent flow field with point-wise anemometry. Therefore, using Particle Image Velocimetry (PIV) is a promising technique to solve this problem. This paper firstly gave an introduction of the typical PIV technologies used in indoor environment measurement, and then summarized the state-of-the-art applications of PIV in measuring the indoor airflow fields. The overview shows that PIV has gradually become the most popular and versatile tools for measuring various indoor airflow fields. The quantitative and detailed turbulent flow information obtained by PIV is critical for analyzing turbulent properties and validating numerical simulations. Specifically, the authors focused on the pros and cons of PIV measurement and gave the typical parameters of PIV used in indoor airflow field measurements. Generally, the researchers should pay more attention to the selection of appropriate PIV system parameters according to their specific research needs. The accuracy of PIV measurement was also discussed. Nevertheless, PIV is not always the optimum tool for indoor airflow measurements. Measurement systems using commercial PIV are often restricted to the block of optical paths and the size limit of image. It is necessary to develop large spatial scale optical system and camera shooting technology to overcome these limitations. Cao, X., Liu, J., Jiang, N., and Chen, Q. 2014. “Particle image velocimetry measurement of indoor airflow field: A review of the technologies and applications,” Energy and Buildings, 69, 367-380