Development of a Numerical Wind Tunnel "Kazamidori" for Predicting Super Typhoons～Using numerical simulations to predict the impact on buildings, wind force and flow can be visualized.～
Sep 4, 2020
Takenaka Corporation
Takenaka Corporation (Presidenta: Masato Sasaki) has developed "Kazamidori" a numerical wind tunnel that can accurately predict the effects of constantly changing winds on buildings through numerical simulations. Numerical Wind Tunnel "Kazamidori" solves a variety of architectural and outdoor wind problems by predicting and visualizing wind force and flow on a computer, and evaluating wind loads (the force of wind acting on a building) and wind speeds.
In recent years, typhoons that hit Japan have become more powerful, and there are concerns that the number of powerful super typhoons will continue to increase. In order to construct buildings resistant to typhoons, it is necessary to evaluate wind loads and reflect them in the shape of a building, the area and thickness of window glass, and the type of claddings. Then, to evaluate the wind load of a building with high accuracy, wind tunnel tests have been widely conducted, in which a model of the building to be evaluated and its surrounding urban area is built and the wind is actually applied to the model for measurement. However, wind tunnel testing has been limited to large projects because of the cost and time required to build models. "Kazamidori" can be used for a wide range of projects because it can be easily applied in small and medium size projects or in the early stages of design which is made possible through reductions in cost and time required to build models for wind tunnel experiments by reproducing urban areas on a computer.
Furthermore, by linking the results of weather analysis utilizing weather conditions such as atmospheric pressure patterns, it becomes possible to reproduce the weather conditions in urban areas when a specific typhoon hits. Since it is possible to not only reproduce past typhoons, but also to envisage super typhoons, which are expected to increase in the future, it is also possible to utilize the results for typhoon damage risk assessment.
Takenaka will use the Numerical Wind Tunnel "Kazamidori" from the initial design stage to provide a building that is both secure and safe from strong winds and economically rational. The AI technology developed by our company will also be used to contribute to the realization of technologies that can quickly predict disasters caused by strong winds.
- ※1:Super typhoon: A class of maximum intensity (130 kts (About 66.9 m/s) or higher), as classified by the one-minute average maximum surface wind speed of the United States Joint Typhoon Warning Center (Kazuhisa Tsuboki; Super Typhoon, TENKI(in Japanese), Vol. 65, No. 6, pp. 73, -75, 2018)
- ※2:2019 Japan Association for Wind Engineering Award (Paper Award) "Optimization Calculations and Machine Learning Aimed at Reduction of Wind Forces Acting on Tall Buildings and Mitigation of Wind Environment."
Outline of Numerical Wind Tunnel "Kazamidori"
The numerical simulation used in the past for the assessment of building winds is a method to calculate the average wind flow in a short time, so it was not possible to calculate the peak wind force required for the assessment of building wind loads. With "Kazamidori," it has become possible to calculate the drastically changing wind force in a numerical simulation by utilizing a method that can calculate wind flow changing from moment to moment.
Features of Numerical Wind Tunnel "Kazamidori"
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①Tool to address building and wind issues
In addition to wind load evaluation, " Habitability due to wind shaking," "existence of unstable aerodynamic vibration " and "maximum wind velocity around the building" can be evaluated. -
➁Tools that can be linked to the results of weather analysis
By reproducing and simulating the flow of wind in a block when a specific typhoon in the past or a super typhoon in the future hits, the force of wind during a typhoon that affects not only buildings but also a wide area such as a block can be evaluated. -
③Tools that can be linked to the results of weather analysis
By reproducing and simulating the flow of wind in a block when a specific typhoon in the past or a super typhoon in the future hits, the force of wind during a typhoon that affects not only buildings but also a wide area such as a block can be evaluated. -
④Tools for evaluating complex buildings
Detailed calculation results can be obtained even with wind forces acting on complex buildings and small parts, which do not come out well in wind tunnel experiments. -
⑤Tool for visualizing wind flow and wind force changes in animation
The flow of wind and the pressure of wind on a building surface, which cannot be seen in real life, can be visualized with animations such as contour diagrams, vector diagrams, and flow line maps.