Wind is an environmental parameter of the microclimate that urban designers are not taking into account in the design process however it is directly connected with satisfaction in urban open spaces (Stathopoulos, 2006; Tacken, 1989; Walton et al, 2007). Wind flow within urban canopies affects pedestrian comfort and as a consequence their use by people, increasing the interest in the research field of pedestrian wind comfort criteria in outdoor spaces. Some of the research projects are available for search in bibliography references.
There are many methods in literature to assess Pedestrian Level Wind (PLW). PLW can either be quantitative or qualitative according to the nature of their outputs, point method or area method, according to the measuring approaches, and mechanical, thermodynamic, optical, or electric according to the physical principles [Ghosh and Mittal, 2012, p.491-506]. Lawson and Penwarden extended "Land Beaufort Scale" presenting wind effects on pedestrians (Fig_21) (Lawson and Penwarden, 1975, pp. 605-622).
It is commonly accepted that majority of these criteria are subjective and they are not dependent only on one value that causes the discomfort, i.e. wind speed. Apart from the psychological parameters there are some others such gustiness, duration, frequency of occurrence and uniformity that affect comfort criteria. There has been quite extensive research work on this field and from CFD point of view most indicative ones can be found in Murakami 1990, Stathopoulos and Baskaran 1990, Gadilhe et al. 1993, Bottema 1993, He and Song 1999, Yoshie et al. 2007, Blocken et al. 2007a, 2008b.
This thesis adopts the extended Land Beaufort Scale method as comfort criterion in order to assess the final result. The choice of extended Land Beaufort Scale is why CFD simulation provides only steady winds calculation.
There are many methods in literature to assess Pedestrian Level Wind (PLW). PLW can either be quantitative or qualitative according to the nature of their outputs, point method or area method, according to the measuring approaches, and mechanical, thermodynamic, optical, or electric according to the physical principles [Ghosh and Mittal, 2012, p.491-506]. Lawson and Penwarden extended "Land Beaufort Scale" presenting wind effects on pedestrians (Fig_21) (Lawson and Penwarden, 1975, pp. 605-622).
It is commonly accepted that majority of these criteria are subjective and they are not dependent only on one value that causes the discomfort, i.e. wind speed. Apart from the psychological parameters there are some others such gustiness, duration, frequency of occurrence and uniformity that affect comfort criteria. There has been quite extensive research work on this field and from CFD point of view most indicative ones can be found in Murakami 1990, Stathopoulos and Baskaran 1990, Gadilhe et al. 1993, Bottema 1993, He and Song 1999, Yoshie et al. 2007, Blocken et al. 2007a, 2008b.
This thesis adopts the extended Land Beaufort Scale method as comfort criterion in order to assess the final result. The choice of extended Land Beaufort Scale is why CFD simulation provides only steady winds calculation.
Fig_21
Land Beaufort Scale
for pedestrian wind comfort
Land Beaufort Scale
for pedestrian wind comfort