1. OFFRE XXXX
Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas
WIND ANALYSIS
PM#07

2. Actual CFD model Antenna layout
OFFRE XXXX
Completion of the wind analysis based on the Antenna design proposed after PM3
Actual CFD model Antenna layout
The analysis include:
11 cases in support to the non-repeatable error budget analysis
15 cases in support to the load analysis
These analyses was performed assuming a reference wind velocity equal to 9.5 m/s (Nighttime Primary condition, including dust)
6 cases in support to the load analysis covering wind survival conditions, defined by a wind velocity of 65.0 m/s
The pressure distribution on the elevation structure relevant to all the antenna configurations was provided to EIE

3. Antenna analysed configuration summary
OFFRE XXXX
Antenna analysed configuration summary
Elevation 15 30 45 60 75 90
Azimut x  o
105
120
135
150
165
180
11 Analysis cases in support to error budget (x) 15 Analysis cases in support to load analysis (o) as in EIE proposal documentation 6 Analysis cases in support to wind survival conditions ()

4. Wind Analysis – Error budget Antenna orientations
OFFRE XXXX
Wind Analysis – Error budget Antenna orientations
Static Pressure distribution (Pa)
0_0
Pathlines (m/s)
Air velocity contours (m/s)

5. Wind Analysis – Error budget Antenna orientations
OFFRE XXXX
Wind Analysis – Error budget Antenna orientations
60_0
120_0
180_0
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

6. Wind Analysis – Error budget Antenna orientations
OFFRE XXXX
Wind Analysis – Error budget Antenna orientations
45_45
135_45
0_60
90_60
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

7. Wind Analysis – Error budget Antenna orientations
OFFRE XXXX
Wind Analysis – Error budget Antenna orientations
180_60
0_90
90_90
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

8. Wind Analysis – Load Analysis Antenna orientations
OFFRE XXXX
Wind Analysis – Load Analysis Antenna orientations
0_30
0_45
0_75
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

9. Wind Analysis – Load Analysis Antenna orientations
OFFRE XXXX
Wind Analysis – Load Analysis Antenna orientations
60_30
60_45
60_60
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

10. Wind Analysis – Load Analysis Antenna orientations
OFFRE XXXX
Wind Analysis – Load Analysis Antenna orientations
60_75
60_90
120_30
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

11. Wind Analysis – Load Analysis Antenna orientations
OFFRE XXXX
Wind Analysis – Load Analysis Antenna orientations
120_45
120_60
120_75
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

12. Wind Analysis – Load Analysis Antenna orientations
OFFRE XXXX
Wind Analysis – Load Analysis Antenna orientations
180_30
180_45
180_75
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

13. Wind Analysis – Wind survival Antenna orientations
OFFRE XXXX
Wind Analysis – Wind survival Antenna orientations
0_15
30_15
60_15
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

14. Wind Analysis – Wind survival Antenna orientations
OFFRE XXXX
Wind Analysis – Wind survival Antenna orientations
90_15
120_15
180_15
Static Pressure distribution (Pa)
Air velocity copntour (m/s)

15. Wind Analysis – Pressure Load on Elevation Structure Summary
OFFRE XXXX
Wind Analysis – Pressure Load on Elevation Structure Summary
Elevation Structure (Parabola + Cabin)

16. Wind Analysis – Pressure Load on Apex Structure Summary
OFFRE XXXX
Wind Analysis – Pressure Load on Apex Structure Summary
Apex Structure

17. Wind Analysis – Pressure Load on Legs Structure Summary
OFFRE XXXX
Wind Analysis – Pressure Load on Legs Structure Summary
Legs +y+z
Legs +y-z

18. Wind Analysis – Pressure Load on Legs Structure Summary
OFFRE XXXX
Wind Analysis – Pressure Load on Legs Structure Summary
Legs -y+z
Legs -y-z

19. Wind Analysis – Wind survival conditions Summary
OFFRE XXXX
Wind Analysis – Wind survival conditions Summary
Elevation structure
Apex
leg +y+z
leg +y-z
leg -y+z
leg -y-z
Load survival cases
Azimuth
Elevation
FX[N]
FY[N]
FZ[N] 15
246360
87146
5819
389 88 -1
103 18
157 98 19
-123 54
-99 16 57
-109 7 30
194160
73828
715
-41
-34
298
-294
362
307
423
214 69 93
256
647
-692
437 60
120800
29250
965
-11
-50
1070
-778
398
1149
1214
744
578
580
643
2193
-2015
303 90
56718
-11871
9589
1342 -8
-19
1146
-1035
-314
2069
1944
367
1188
1083
239
2265
-2046
-730
120
77796
-6084
-4096
-159 50 -7
-308
359
183
163
267 34
-183
-232
-28
180
-250
-96
135270
2129
-204
-262
-79 -2
109
-23
112 23
-66
-62
-48
-65 66

20. Wind Analysis – Results Comparison with the PM3 analysis
OFFRE XXXX
Wind Analysis – Results Comparison with the PM3 analysis
The presence of the legs only locally modifies the parabola pressure distribution
old
Static Pressure (Pa)
Azimuth 0 Elevation 0
new

21. Wind Analysis – Conclusions
OFFRE XXXX
Wind Analysis – Conclusions
A complete set of analysis was performed on the basis of the actual Antenna layout, i.e. with included legs
11 Antenna orientations in support to the non-repeatable error budget analysis
15 Antenna orientations in support to the load analysis
6 Antenna orientations in support to the wind survival conditions analysis
All the analyses were performed assuming a reference wind velocity of 9.5 m/s (Nighttime Primary conditions), excepting the wind survival conditions analyses for which the reference wind velocity is equal to 65 m/s
In view of the expression of the aerodynamic force on the Antenna , the pressure loads under different wind conditions can be obtained by scaling according a factor proportional to the square of the velocity ratio, considering that the aerodynamic coefficient has little variation under the given range of wind velocities
From the comparison with the old analyses it turns out that the introduction of the legs on the model only locally modifies the parabola pressure distribution