Ryoji Sasaki

Application of infrared thermography and a knowledge-based system to the evaluation of the pedestrian-level wind environment around buildings

A convenient technique for evaluating the wind environment around buildings in wind tunnel tests has been developed. Infrared thermography and a knowledge-based system are applied to this technique. The evaluation system developed in this study can be used effectively at an early design stage of a tall building development, e.g., when the cross sections and/or the arrangement of buildings are examined from the view point of the pedestrian-level wind environment.

A visual technique for the evaluation of the pedestrian-level wind environment around buildings by using infrared thermography

Abstract A convenient technique for evaluating the pedestrian-level wind environment around buildings by using infrared thermography is developed. In the wind-tunnel experiments using this technique, a building model is placed on a heated floor and immersed in a flow. The temperature distribution on the floor surface is measured by infrared thermography. A comparison is made between the temperature distribution and the quantitative data obtained from hot-wire anemometer tests using several kinds of rectangular prisms. An empirical formula for representing the relationship is derived; in constructing the model, an “effective wind speed” defined as a combination of the mean and RMS wind speeds is introduced. By using this formula, a temperature distribution measured by infrared thermography is converted to the mean speed distribution and is displayed as an image on a personal computer.

Comfort environment assessment based on bodily sensation in open air: relationship between comfort sensation and meteorological factors

Abstract The purpose of this study is to develop a method for assessing the comfort of an open-air environment, based on a questionnaire answered by inhabitants of urban areas. Eighty-nine inhabitants of three cities in the northern part of Japan and 18 inhabitants from the suburb of Tokyo responded to the survey. The dependence of comfort judgement on various meteorological factors was studied by using multivariate regression analysis. To construct a comfort environment assessment model, the focus was on a discomfort ratio, which represents what percentage of the inhabitants feels uncomfortable under certain ambient conditions.

Relationship between surface roughness and turbulence of natural winds near the ground surface

Relationship between surface roughness and turbulence of natural winds near the ground surface