6 Multi-objective Performance Optimization of a Ribbed Solar …
89
4
3
2
1
40
39
38
37
36
35
34
33
32
4
3
2
1
4
3
2
1
A
Mean of SN ratios
B
C
Fig. 6.5 Taguchi—S/N ratios for Nusselt number
4
3
2
1
41
40
39
38
37
4
3
2
1
4
3
2
1
A
Mean of SN ratios
B
C
Fig. 6.6 Taguchi—S/N ratios for friction factor
are as follows: Re = 16000 (A 4 ), p/e = 3 (B 1 ), and α = 45° (C 1 ). Consequently,
A 4 B 1 C 1 is found as the best grouping of design factors associated with the lowest
pressure drop (see Table 6.7).
Figure 6.7 elucidates the prominent impact of design parameters on thermohydraulic performance factor. Thermohydraulic performance decreases with increase in
Re (A), because of significant increase in pressure penalty. While η tends to increase
with the increase of p/e (B). The reason can be attributed to enhancement in heat
transfer and also decrease in friction factor with the increase in rib spacing. However, the η shows same trend as that of Nu with inclination angle, it decreases with
89
4
3
2
1
40
39
38
37
36
35
34
33
32
4
3
2
1
4
3
2
1
A
Mean of SN ratios
B
C
Fig. 6.5 Taguchi—S/N ratios for Nusselt number
4
3
2
1
41
40
39
38
37
4
3
2
1
4
3
2
1
A
Mean of SN ratios
B
C
Fig. 6.6 Taguchi—S/N ratios for friction factor
are as follows: Re = 16000 (A 4 ), p/e = 3 (B 1 ), and α = 45° (C 1 ). Consequently,
A 4 B 1 C 1 is found as the best grouping of design factors associated with the lowest
pressure drop (see Table 6.7).
Figure 6.7 elucidates the prominent impact of design parameters on thermohydraulic performance factor. Thermohydraulic performance decreases with increase in
Re (A), because of significant increase in pressure penalty. While η tends to increase
with the increase of p/e (B). The reason can be attributed to enhancement in heat
transfer and also decrease in friction factor with the increase in rib spacing. However, the η shows same trend as that of Nu with inclination angle, it decreases with