- 一般社団法人 日本機械学会
- 日本機械学会論文集B編 (ISSN:18848346)
- vol.78, no.790, pp.1220-1234, 2012 (Released:2012-06-25)
Japanese cedar (Cryptomeria japonica) pollinosis is the most common allergic diseases in Japan, and some researchers show about 26.5% of population being affected. Japanese cedar pollen is carried by the wind, but the pollen suspension transport behavior must be different from the wind (carrier air flow) behavior because the aerodynamic diameter of this pollen is relatively large. I estimate the mean aerodynamic diameter of Japanese cedar pollen as about 35μm in this study. The pollen falls when the wind is weak, and it is blown up and carried (saltation and resuspension) by the strong wind. If the pollen flow behavior was completely corresponding to the wind, the range of Japanese cedar growth would be very broad and the peculiar distribution of Japanese cedar might be confused. This study aims to clarify the cedar pollen suspension transport behavior and saltation transport mechanism, and to confirm the prediction method of this behavior and mechanism. Accordingly, the followings were done : (1) The aerodynamic diameter of Japanese cedar pollen was measured and the test particle was selected. (2) The suspension and saltation behavior of the test particle was observed and measured by the optical measurement methods. (3) The suspension and saltation behavior was also numerically calculated. These measured and calculated results are shown and evaluated by each other result in this paper. The knowledge about the relation between air and particle velocities is acquired. The saltation mechanism is cleared. The suspension and saltation transport behavior can be predicted by this study method.