turbulent intensity

Investigations were carried out into the airflow in a non-unidirectional airflow cleanroom and its affect on the local airborne particle cleanliness. The main influence was the method of air supply. A supply inlet with no diffuser gave a pronounced downward jet flow and low levels of contamination below it, but poorer than average conditions in much of the rest of the room. A 4-way diffuser gave much better air mixing and a more even airborne particle concentration throughout the cleanroom.

Features of natural wind and artificial airflow are related to human thermal sensation. Based on the existing records of natural wind and artificial air movement, their turbulent intensity of velocity fluctuation, energy spectra. probability distribution of velocity are compared and analyzed.

Air movement can provide desirable cooling in "warm" conditions, but it can also cause discomfort. This study focuses on the effects of turbulent air movements on human thermal sensations through investigating the preferred air velocity within the temperature range of 26°C and 30.5°C at two relative humidity levels of 35% and 65%. Subjects in an environmental chamber were allowed to adjust air movement as they liked while answering a series of questions about their thermal comfort and draft sensation.