Kitchens are easier to use if they are easier to clean. To achieve
this, it must be easier to flush dirt and waste to the bottom of the
sink and to clean it away efficiently.
LIXIL’s new product introduced the “Niagara Flow Type”, where
the bottom of the sink slopes more from the left and right edges,
preventing water from spreading and flowing smoothly towards
down. This allows for efficient drainage from anywhere in the sink.
Particleworks was used to evaluate how effective the new shape
is. The kitchen sink design was evaluated in tests based on a very
large number of assumptions, including how to flush waste.
In the Particleworks simulation, we first tried to reproduce how
easily it was for regularly spaced waste to flow. The analysis
currently being performed checks how the waste placed at
equal intervals flows. Instead of performing detailed settings by
coupling Particleworks with RecurDyn, as was done in the shower
head simulation, the water supply conditions were set using the
Initial simulations showed that the water flowed faster, slipped
more, and spread less compared to the test. The waste was also
flowing unnaturally. Therefore, a test was conducted on a simple
shape to obtain parameters by associating the test results with the
simulation results. In actual phenomena, a film of water penetrates
under the waste and surrounds it making the
In the Particleworks calculations, particles didn’t
penetrate below the waste as easily in the first trial.
This was solved by making the particles smaller.
However, this required a lot of computational
To reduce the computational load and shorten
the simulation times to less than a day, it was
necessary to enlarge the particles to some
extent. However, this caused some differences
from the actual phenomenon. Therefore, several
attempts were made to adjust the frictional force
parameters to approximate the behavior of the
Regarding the definition of the frictional force,
it was found that it was easier to adjust the
parameters by setting the waste with polygons
in RecurDyn, so a simulation was performed
coupling Particleworks with RecurDyn.
Next, the frictional force and particle shape were
defined to prevent the waste from moving before
the water supply. A correlation was made by
adjusting the frictional force and the transition
Through trial and error, the reproduction of
water spread and the behavior of the waste were
improved compared to the first simulation, and
could also be improved compared to the actual
Although the final result for this simulation has
not been obtained, LIXIL continues to try to
simulate through trial and error.
Dr. Miyazawa said, “The Particleworks features are a great
advantage because they allowed the behavior of the shower and
the internal impellers to be easily reproduced.”
Fig. 4 - Water flow simulation for conventional type (left) and Niagara Flow Type (right)holes