buletinul institutului politehnic din iaşi - Universitatea Tehnică ...

46 Nicolae Bara and Marin Bica
velocity. There were calculated the volume and mass air flow, and the air
density at average temperature was determine using the tables. The obtained
values are listed in Table 2.
Nr.
S,
m 2
ρair
kg/m 3
Table 2
Values measured to determine the air flow
t′ air
o
C
t′′ air ,
o
C
tair, m
o C
wair
m/s
Vair
m 3 /s
mair
kg/s
1 0.0279 1.205 22 18 20 2.64 0.07385 0.089
2 0.0279 1.208 22 16.2 19.1 3.47 0.09685 0.117
3 0.0279 1.212 22 14.3 18.15 3.90 0.10891 0.132
4 0.0279 1.215 22 12.8 17.4 4.34 0.12128 0.147
The parameters obtained for the step of 0.002 were measured in order to
highlight the influence of the rib step width dimensions, and then they were
calculated for other values. The measurements and calculations results were
listed in Table 3.
No.
Table 3
Values determined by calculus for different dimensions of the air flow channel
Channel
width
t′ air
°C
t′′ air
°C
t air. m
o C
ρ air
kg/m 3
w air
m/s
m air
kg/s
1. 0.001 28.4 22.3 25.35 1.183 2.68 0.0792 0.025
2. 0.001 28.4 20.2 24.3 1.188 3.86 0.1146 0.025
3. 0.001 28.4 18.1 23.25 1.192 4.22 0.1257 0.025
4. 0.001 28.4 16.8 22.6 1.194 4.84 0.1444 0.025
5. 0.001 28.4 16.2 22.3 1.195 5.02 0.1499 0.025
6. 0.001 28.4 15.8 22.1 1.196 5.18 0.1548 0.025
7. 0.001 28.4 15.2 21.8 1.197 5.45 0.1630 0.025
8. 0.001 28.4 14.8 21.6 1.1986 5.89 0.1764 0.025
9. 0.0015 28.4 20.1 24.25 1.188 2.68 0.0865 0.0264
10. 0.0015 28.4 19.2 23.8 1.189 3.86 0.124 0.0264
11. 0.0015 28.4 18.4 23.4 1.191 4.22 0.1364 0.0264
12. 0.0015 28.4 17.6 23.00 1.193 4.84 0.1568 0.0264
13. 0.0015 28.4 17.1 22.75 1.194 5.02 0.162 0.0264
14. 0.0015 28.4 16.4 22.4 1.1954 5.18 0.185 0.0264
15. 0.0015 28.4 15.6 22.00 1.197 5.45 0.190 0.0264
16. 0.0015 28.4 14.2 21.3 1.1998 5.89 0.1944 0.0264
17. 0.002 28.4 19.2 23.8 1.189 2.68 0.0866 0.0272
S
m 2