Optimization and Computational Fluid Dynamics - Department of ...

8 Multi-objective Optimization in Convective Heat Transfer 261
Surface Area Variation (%)
Surface Area Variation (%)
−0.5
−1
−1.5
−2
Pareto Front
−2.5
−25 −20 −15 −10 −5 0
−1.7
−1.75
−1.8
−1.85
−1.9
−1.95
Pressure Drop Variation (%)
o
θ =42
(a)
o
θ =43
337
173
338
334
130, 335
134
o
θ =44
−2
−20 −19 −18 −17
Pressure Drop Variation (%)
(b)
Fig. 8.24 Pareto fronts for the CC channel: ♦ feasible designs, + unfeasible designs, ◦
Pareto front, (a) Paretofronts,(b) designnumbers
pressure drop and surface area as shown in Fig. 8.24(b) while maintaining
the same heat transfer characteristics. This trend is maintained up to an angle
of 42 ◦ , while for lower values the same heat transfer characteristics could
not be maintained. These correspond to unfeasible results, since the value of
the mean Nusselt number is lower than that of the original design 0.
Among the designs that belong to the Pareto front, the design 134 has
been chosen for illustrative purposes. In fact it has less than 19% pressure
gradient β, and a surface area 2% lower than that of the original one while