Noriko Chino’s scientific contributions

The wind pressure differences across the exterior panels which were attached to concrete walls using non-sealed joints were measured on windy days. The air spaces between the exterior panels and the concrete walls are partioned in order to interrupt the air flow. Measurements confirmed that the 10-min. average wind loads on the exterior panels were nearly zero and the fluctuating wind loads on the exterior panels were also smaller than those on the entire wall consists of exterior panels and parapet.

We have installed two wind tunnels of closed return type for carrying out our research in wind environment around tall buildings, aerodynamic stability of structures, and design of external materials.One of these tunnels has a working section of 1.8m in height, 2.0m in width and 16m in length.The other has a working section of 2.0m in height, 3.0m in width and 16m in length.The characteristics and performance of the wind tunnels are presented in this paper.

An analytical approch for predicting the mean and fluctuating internal pressure induced by wind between double walls when the outer wall is provided with openings has been investigated. The method of analysis was based on jet simulated air-flow through the openings and a model of pressure flow between parallel planes. The analytical results were compared with wind tunnel results, and they matched closely if the proper values for flow resistance between the double walls were used. From these results, the analytical method described in this paper was found to be effective in predicting the mean and fluctuating internal pressure between the double walls.

Extreme wind speeds for various return periods during rainfall at 49 meteorological stations in Japan were estimated using the statistical method for extremes. The 10 minutes average wind speeds and hourly precipitations for 13 years were used for analysis. These wind speeds were classified into seven categories according to the amount of hourly precipitation. Annual maximum wind speeds in each precipitation class were then extracted from these data. Multiple regression analysis, which assumed that annual maximum wind speed during rainfall was a linear function of a reduced variate and of hourly precipitation, was used to fit the extreme type-I distribution.

Extreme wind speeds for various return periods during rainfall at six typical meteorological stations in Japan were estimated using the statistical method for extremes.The annual maximum wind speeds recorded from 1961 to 1980 at these stations were used for analysis. The annual maximum wind speeds were classified according to the amount of precipitation, and they were found to be well modelled by the extreme type-I distribution. Multiple regression analysis employing two parameters, i.e., annual maximum wind speed and hourly precipitation, was used to fit the type-I distribution.

In 1981, International Aylesbury Collaborative Experiment was set up. This experiment is based on the full scale measurements at Aylesbury site and seeks to improve the assessment of wind-induced load on low-rise buildings through model scale tests. We participated in this collaborative experiment and have carried out pressure measurements on a 1:100 scale model of Aylesbury experimental house. The main purposes of our wind tunnel tests are, firstly, to make a comparison with the full-scale data and with similar results from other wind tunnels, and secondly, to study the effect of differences in approach flow. The results are summed up as follows. 1) The mean velocity and turbulence intensity profiles were generally in close agreement with full-scale data. 2) The mean pressures measured in our wind tunnel were generally in agreement with full-scale data, although some differences appeared in a few cases. 3) High correlation was obtained between our wind tunnel tests and other wind tunnel tests. 4) The profiles of turbulence intensity in approach flow had significant effects on the measured fluctuating pressures.