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scSTREAM, a Remarkable CFD Tool for Architectural Design
Easier, Quicker and Better Features
She also pointed out that the ease of geometry and mesh generation was one of the strengths of scSTREAM. “The ability to easily import Rhino and SketchUp geometries was a big advantage that we were not even originally considering. This saves me a lot of time, and allows us to model exactly what architects need to be modeled. The several meshing options offered by scSTREAM are something we had not seen in other software within our price range. Meshing has never been easier,” she said. Furthermore, one of the features Dr. Menchaca really liked was the scSTREAM GUI. “This is where scSTREAM was probably the most superior compared to other CFD packages. The scSTREAM interface is very intuitive and defining boundary conditions – often the most painful part of setting up a simulation – is extremely simple. I tend to skip ‘wizards’ in most software, but scSTREAM’s external airflow simulation wizard is a true time saver.” The external airflow simulation wizard sets the boundary conditions for all six computational boundaries with only a couple of clicks and typed inputs.
When Dr. Menchaca talks about simulation time she says “we cannot afford to run week-long simulations, although while we are still waiting for the perfect day when CFD simulations take one minute to complete, scSTREAM simulation times are relatively short.” Because of scSTREAM's reasonable cost and efficient performance Dr. Menchaca could run a simulation on her laptop if needed. This enabled her to continue running jobs when she was away from her office.
CFD Analysis at a Design Firm and the Future of CFD for Architecture
CFD analysis is known to help designers and engineers understand and improve their architectural designs. However, practitioners in the architectural field often say they are hesitant to commit to CFD. Dr. Menchaca provided her thoughts on this matter. “I think the current usage of CFD in the architecture industry has not reached its full potential. Because of cost, time and expertise required, running a CFD simulation means waiting for at least a month to get an answer to any questions.” The time required to perform a CFD analysis is certainly an issue that affect the role of CFD in the design processes. According to Dr. Menchaca, time is an even greater constraint when the architectural firm outsources the CFD work to a supplier. “By the time the CFD results are received, the building is likely to have changed dramatically. This means that, in general, we will only outsource CFD studies for building elements that are less critical.” In contrast, the situation is entirely different at Payette where building scientists conduct energy modeling and CFD analysis alongside their design team. Dr. Menchaca described the benefit of having CFD capabilities in-house. “Having CFD capabilities in-house allows us to speed up the simulation process to a week or so, and also allows us to tweak and explore more options as the design evolves.”
She also explained some of the differences between the current design process and the past. “Our office used to hire outside consultants to evaluate indoor thermal comfort conditions or to conduct wind studies, studies which usually require about one month to get results. Now we do most of the early design simulations in-house, which has allowed us to use the results to modify the building design. This saves us both money and valuable time.”
CFD will make greater contributions to the architectural industry as technology continues to improve “the easier and quicker it becomes to run accurate CFD simulations, the more CFD will be used as a tool that impacts building design, rather than an afterthought.” Dr. Menchaca compared this to the way energy modeling has slowly become more common in the early design stages and now impacts the design process.
Lastly, Dr. Menchaca was asked about one feature she would like to test with scSTREAM. “I have not had the chance to really test particle dispersion, which is extremely relevant for us, particularly in the healthcare practice. Also, I would like to run parametric tests with scSTREAM, to evaluate several design options without having to set each case up, just like the Wind Tool does when it tests several wind directions.”
Dr. Menchaca's application example of scSTREAM indicates that scSTREAM will play even more significant role in building design in future.