Topology/shape optimization of heat transfer surfaces
There are many devices related to heat and fluids, and this is a field where there are high needs for design issues and improvements. For example, for components exposed to high-temperature fluid such as jet engines and turbine blades used for thermal power generation, the components themselves will melt or break when the heat-resistant temperature is exceeded, so a structure that allows cooling air to flow while releasing heat is required.
With the rapid spread of information terminals and electric vehicles, cooling of electronic devices has
become an important issue. Since electronic components may malfunction or fail due to heat, various
air-cooling and water-cooling mechanisms have been devised. Modern society is established on the basis of
energy conversion, and control of heat transport, which is one of the most commonly used energy forms, is
extremely important from the viewpoint of effective energy use. Equipment that exchanges heat between
different fluids is generally called a heat exchanger, but if a more efficient heat exchanger can be designed,
it can greatly contribute to energy saving.
The "deterministic optimization tool for complex
three-dimensional shapes" developed by our laboratory is effective in optimizing the parts and structures
related to such thermal fluids.
A flow path with wavy unevenness has been proposed as a flow path for efficiently extracting heat. The adjoint
analysis program of our laboratory was applied to this shape, and the optimum heat transfer surface shape was
calculated.
The movie shows the sensitivity distribution of the heat transfer surface obtained by the
adjoint analysis. The optimum shape is sought by changing the shape according to the obtained sensitivity.
(left) Shape
optimization and (right) topology optimazation of oblique wavy wall for enhancing heat transfer and
mitigating pressure loss
The color on the wall shows the local sensitivity to a cost
functional.
Shape optimization of pin-fin array for enhancing heat transfer and
mitigating pressure loss
The color on the pin fin shows the local sensitivity to a cost
functional.
The figure on the right shows the changes of pressure loss and heat transfer rate with
increasing the iteration for updating the pin-fin shape.
It can be seen that the ratio of heat transfer
and pressure loss is improved with increasing the number of update.
Reference: Kametani et al., J.
Thermal Science and Technology (2020)
It is extremely important to experimentally verify the calculated optimal shape.
In our laboratory, the
shape obtained by the optimization calculation is created with a 3D printer, and the fluid is actually flowed
and measured. We also verify the performance by comparing the calculated results with the experimental
results.
It is rare for one laboratory to carry out everything from optimization to its demonstration, and
this is another feature of this laboratory. Regarding shape optimization, we are actively conducting joint
research with companies such as the automobile industry and heavy industry, and the results are reflected in
many patents.
Topology Optimization of Electrolyte-Anode
Interface in solid oxide fuel cell
Left) Problem setting, Middle) Optimization from
different initial conditions (color: iso-surface of potential),
Right) Interfacial structures and
potential distributions at the bottom
Reference: Onishi et al. J. Electrochem. Soc (2019)
Poster
