Simulating complicated wind flows around buildings and the surrounding environment used to mean conducting wind tunnel tests that required a long time, large-scale facilities, and skilled experts. Now, many of the experimental tests are being replaced by computational fluid dynamics (CFD) simulations. Combining these two approaches draws on the advantages of each and is commonly done in engineering today. But Mr. Tetsuo Matsuyama from WindStyle Corporation, who has used scSTREAM for many years, envisions additional opportunities for CFD. He explains how using scSTREAM proactively to interpret wind flow can change design processes and building management.
“What I like about scSTREAM is its high compatibility with other software. Flexible input and output functions is another advantage. I can choose a range of input formats when I import mapped data for an area of a city model. I can also create my own scripts and execute analysis. Our team created own software that adjusts the visualization of the analysis results based on the mesh coordinates so that the results look smooth” explains Mr. Matsuyama. His clients and business partners, who are not familiar with CFD simulations, find it easier to understand the visualized analysis reports.
According to Mr. Matsuyama, the excellent customization capabilities of scSTREAM are deeply linked to the first-rate support from Software Cradle. “Having discussions with Cradle engineers absolutely helps. They understand my specific customization requests. scSTREAM is not just designed to enable easy customization. Cradle regularly updates software functions according to user needs, and that is what really works for the scSTREAM user's benefit,” says Mr. Matsuyama.
Mr. Matsuyama’s current approach involves combined wind tunnel testing (Picture 2), and CFD virtual simulation (Figure 3 and 4). “Wind tunnel testing has led the field of wind engineering, but it is beginning to be replaced by computer simulations. Usually, research and development of these two methods are conducted separately, but our team incorporates both. We simulate and test simultaneously to capture the advantages of both,” explains Mr. Matsuyama.
Mr. Matsuyama points out that the outputs from wind tunnel testing and CFD simulation for building wind analysis are completely different. Wind tunnel testing is used for time history analysis of a particular area. The law of similarity speeds up the duration by 100 times. This means changes that occur over 10 minutes can be observed in 10 seconds. On the other hand, CFD simulation examines the entire space. Average values are used for calculation, and calculation takes 100 times longer. The upside for CFD is that the preparation time is much shorter. Only a few days are needed to prepare for CFD simulations. In contrast, preparing for wind tunnel testing can take two months. “These two tools have very different characteristics. I choose which to apply depending on the case I am working on. Sometimes I use one to supplement the capabilities lacking in the other. We also use software we developed, to correct the differentials between wind tunnel testing and scSTREAM analysis results,” says Mr. Matsuyama.
Mr. Matsuyama is currently exploring the novel ways to combine wind tunnel testing and CFD. “I think of scSTREAM analysis results as the value of interpolation space. I’ve tried printing out the analysis model on a 3D printer to evaluate in wind tunnel experiments. The costs of 3D printing have been reduced dramatically. The value of CFD will extend even further if we can download geographical data around planned buildings,” comments Mr. Matsuyama.
Shortly after he first started using scSTREAM, Mr. Matsuyama identified the significance of network clusters to further improve the accuracy of scSTREAM. “scSTREAM became cluster-compatible early, so I expected that using the tool for wind engineering could be as effective as it is used in automotive and machinery applications. But I also knew wind engineering applications would present its own challenges. The biggest bottleneck was that the software license configuration was not designed specifically for the construction industry, despite the calculation complexity. In the construction industry, the use tends to grow larger with building evaluations, and the number of analyses patterns also tends to increase. Another drawback was that results could not be reused easily for the building analyses. We were frustrated because this powerful tool was not accessible for use in many projects, even though it was conceptually designed for the convenience of everyone,” reveals Mr. Matsuyama. Cradle developed a possible solution to this problem. Cradle products became available at daily usage rate from a Japanese cloud service provider, starting from fall 2014*. “I think this is the first CFD software developed by a Japanese firm, which is available under a pay-per-use plan. This is certainly going to encourage more use of CFD.”
* Only available in Japan
Simulation of wind environment is not only used to examine wind damage. Mr. Matsuyama expects there is more potential to the application of scSTREAM. “CFD simulation results can be used to discuss building design and management between designers, constructors, governments, and local residents, if it is more commonly used. CFD will prove to be effective in risk management for clients.” It is also possible to improve building designs, by implementing wind power generation system using wind load, and incorporating natural ventilation system into the building model. “If we use CFD simulations for building designs to improve natural ventilation effects, it is possible to switch off the air-conditioner and still maintain the comfort level for a longer period of time. This attempt can happen nationwide. Interpreting wind effects from a different perspective helps effectively utilizing wind. CFD application can generate greater values to any buildings.”
Conveying the value of wind engineering to a wider audience is one of Matsuyama’s future visions. “I’m trying to figure out a system for anyone to be able to visualize invisible wind whenever and wherever. My plan is to have scSTREAM at the center of this system. As more non-experts become familiar with wind effects, more specific demands will be created, and scSTREAM will be used more widely. That’s what I believe.” Application of scSTREAM to wind engineering has the potential to dramatically improve the surrounding conditions in architectural designs. This can favorably impact public acceptance of wind engineering environmental management and its implementation.
|Business||Research and development of wind engineering related technology, and provision of technical services and support|
|Representative||Tetsuo Matsuyama, President and CEO|
|Locations||Head Office in Niigata-shi, Niigata, Japan
Narashino STUDIO in Narashino-shi, Chiba, Japan
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