Download - NSTX TF Flag Joint Design Review
AWB 041003 1
NSTX TF Flag Joint Design Review
April 10, 2003
Art Brooks
AWB 041003 2
Overview of TF Flag Analyses
• Thermal/Electrical Response ( ANSYS )– Impact of Assumed Contact Resistance on Joint
temperature and pulse length
• Inductive Effects ( SPARK )
• Force Distribution ( SPARK )
AWB 041003 3
ProE Model of TF Flag Geometry
Epoxy layer(not present in latestdesign)
Contact region
Inner LegOuter Turn
AWB 041003 4
Geometry Imported to ANSYS and Meshed
Higher order tetra elementsused to auto-mesh irregular geometry
71/2 KA Current
AWB 041003 5
Contact Region Modeledas finite thickness withequivalent resistivity
AWB 041003 6
71 KA Waveform Driving Thermal Model
0
10000
20000
30000
40000
50000
60000
70000
80000
-1 -0.5 0 0.5 1 1.5 2 2.5
Full I2T L/R
108712
Analytic
Analysis assumes the Full I2t (6.5e9 a2s) based on .7 sec FT and L/R decay.
AWB 041003 7
End Of Flat-Top Temperature Distribution
assuming 6 in2
Note:
6 in2
Contact Resistancerequires ~1.4 ksicontact pressure(Copper-on-Copper)
AWB 041003 8
End Of Flat-Top
Temperature Distribution
AWB 041003 9
End of Pulse Temperature Distribution assuming 6 in2
AWB 041003 10
Temperature Peaks shortly after EOFT
176 C
Flat top would have to be shortened to ~0.26 s to limitmax temperature to 120 Cat 6 -in2
AWB 041003 11
Note:4 micro-ohm-in2Contact Resistancerequires ~2.0 ksicontact pressure(Copper-on-Copper)
End Of Flat-Top Temperature Distributionassuming 4 in2
AWB 041003 12
End Of Pulse
Temperature Distribution
AWB 041003 13
Flat top would have to be shortened to ~0.41 s to limitmax temperature to 120 Cat 4 -in2
Again, Temperature Peaks shortly after EOFT
AWB 041003 14
End Of Flat-Top Temperature Distributionassuming 1 in2
Note:
1 in2
Contact Resistanceexpected with Silver Plated Joint and minimum 1 ksi press
AWB 041003 15
AWB 041003 16
End Of Pulse Temperature Distributionassuming 1 in2
AWB 041003 17
Temperature Peaks shortly after EOFT
Flat top of 0.7 s achievableMax temperature less than 120 Cat 1 -in2
AWB 041003 18
Flat Top Time to Limit Max Temperature at Joint to 120 C
71 KA Waveform, L/R Decay
0.0
0.2
0.4
0.6
0.8
1.0
0 2 4 6 8Contact Resistance, -in2
Fla
t top
, sec
120 C Limit at Joint
~80 C Limit in Turn
AWB 041003 19
Thermal Response Summary
• Peak Temperature at Joint occurs near threaded inserts, but localized
• Peak Temperature very dependent on Assumed contact resistance– Higher than expected contact resistance will force
shortening of flat top at 6 kG– Full I2t achievable at 1 -in2
• Bulk Heating of Flag small.• Bulk Temperature not significantly impacted by
assumption of contact resistance
AWB 041003 20
Inductive Effects
• ANSYS analyses of Joint Heating assumed currents were resistively distributed
• SPARK Model used to assess current penetration• Time constants for current penetration shown to
be small
AWB 041003 21
SPARK Model of NSTX TF Coil
Geometry Only With Current Flow
AWB 041003 22
t=.01 s t=. 1 s
Current Penetration very quick
Current penetrates from both sidesof Lower Flag due to field from Upper Flag
Current nearly resistively distributed
AWB 041003 23
Current Fraction In Upper Half of Upper TF Flags
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0 0.5 1
Time, sec
Fra
ctio
n i
n U
pp
er H
alf
Inner Leg Inner Turn
Inner Leg Outer Turn
AWB 041003 24
EM Force Distribution In Flags
• Spark Model Also Used to Determine EM force distribution in Flag from TF Field– Out of Plane forces from PF not repeated at this time.
• Forces Calculated for split flag configuration• Resultant forces predominately vertical with 1/R
distribution• Forces not recalculated for solid flag, but
– Vertical forces should still have same 1/R behavior and magnitude
– Radial forces should be larger in flag and should work to keep joint closed
AWB 041003 25
Force Distribution on TF Flags
0
100
200
300
400
500
600
700
800
900
1000
0.00 5.00 10.00 15.00
Distance from Contact Joint, in
Ru
nn
ing
Lo
ad
, l
bs
/in
Upper Flag, Upper Half
Upper Flag, Lower Half
Lower Flag, Upper Half
Lower Flag, Lower Half
1/R fit LL
1/R Fit LU
1/R Fit UL
1/R Fit UU
Note: Jump in loadsat ends results fromchange in FEA mesh density
AWB 041003 26
2 D distribution of IL Outer TurnFlag Forces
Radius, in 0.00 1 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 9.50 10.0 10.5 11.0
Lower Flag 63 67 64 60 55 51 46 43 39 36 33 31 29 27 25 24 22 21 20 18 17 17 33 Upper Half 136 146 137 129 120 110 102 94 87 81 76 71 66 62 59 56 53 50 47 45 43 41 83(Forces in Newtons) 159 172 160 149 138 127 118 110 103 96 90 85 81 76 73 69 66 63 60 58 56 54 111
184 200 181 165 151 138 128 120 112 105 99 94 89 85 81 77 74 71 68 65 63 61 128215 236 204 180 162 148 137 128 120 113 107 102 97 92 88 85 81 78 75 72 69 66 142132 133 106 90 81 74 68 64 60 57 54 52 49 47 45 43 42 40 39 37 35 33 89
Running Load, lbs/in 400 429 383 347 317 291 270 251 234 220 207 195 185 175 167 159 152 145 139 133 127 122 2631/R Fit 484.013 429 384 349 319 294 272 254 238 223 211 200 189 180 172 164 158 151 145 140 135 130 126
Lower Flag 108 119 125 124 118 110 102 95 88 82 77 72 68 64 61 58 55 53 50 48 47 47 99 Lower Half 233 265 261 255 241 226 210 196 183 171 161 151 143 135 129 122 117 112 107 103 100 96 182(Forces in Newtons) 284 318 299 282 263 245 227 212 198 186 176 166 157 149 142 136 130 125 120 115 111 106 203
347 387 347 313 285 261 242 225 211 198 187 178 169 161 154 147 141 135 130 125 120 115 223419 480 406 349 309 281 259 242 227 215 204 194 185 177 170 164 157 152 146 141 135 130 255285 286 223 184 162 147 136 128 121 115 109 105 100 96 93 90 87 84 81 78 75 72 144
Running Load, lbs/in 754 834 747 677 620 570 529 494 462 435 411 389 369 352 337 322 309 296 285 275 265 255 4971/R Fit 942.386 834 748 679 621 572 530 494 463 435 411 389 369 351 335 320 307 294 283 272 262 253 245
AWB 041003 27
Summary
• Thermal distributions and EM loading provided as input to Structural Analysis being performed and presented by Irv Zatz