August 7, 2003K. Chow, LHC Luminosity Detector Thermal Analysis1 Analysis cases Approach: Start...

August 7, 2003 K. Chow, LHC Luminosity Detector Thermal Analysis 1

Analysis cases• Approach:

Start simple to get information— • with speed

• with confidence

• that is useful

Description Geometry Loading1 Comparison with rough estimate rectangular block Uniform heat generation2 Block of SS with beam heating same as case 1 Beam profile = circular3 Block of Cu with beam heating equiv volume and surf area Beam profile = square4 Block of Cu inside Macor equiv volume and surf area Beam profile = square5 Cu inside Macor inside SS equiv volume and surf area Beam profile = square6 Detailed geometry actual but defeatured Beam profile = circular7 Detailed geometry actual but defeatured Beam profile = truncated gaussian


Case 1: hand calc comparison model

4.55 cm

18.1 cm

18.1 cm

-Uniform heating of block using equiv volume heat generation (36.3W)-Same surface area (982 cm^2)-Radiation to “space” node at 298K (view factor=1)-Larger mass than hand calc-Emissivity = 0.1


Case 1: comparison results

• Steady state temperature same as hand calc– 520 K

• Transient results same as hand calc if we set hand calc mass equal to FEA model mass

520K


Case 2: SS block with circular heating

Steady state

temps

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0.0014

0.0016

0.0018

0.002

-20 -15 -10 -5 0 5 10 15 20

Axisym m etric beam profile (m m )

Bea

m h

eat

load

(W

/mm

^2/m

m d

epth

)

-Power deposition = 0.798 W/mm-Absorbed thickness = 45.5 mm-Absorbed power = 36.3 W-Xsec area of heated volume = 491 mm^2-SS conductivity = 16.3 W/m-K-SS density = 8.0 g/cc-SS C = 0.5 J/g-degC-Emissivity = 0.1-Mass = 11.9 kg


Truncated gaussian beam profile

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

-15 -10 -5 0 5 10 15


Case 2: SS block with circular heating

• Transient results

295

345

395

445

495

545

0 10 20 30 40 50 60 70 80 90 100

Time (hr)

Tem

p (

K)

Center

Corner

whole block heating


Case 3: Copper block by itself

87 mm

79 mm15.3 mm

-Power deposition = 0.876 W/mm-Absorbed thickness = 15 mm-Absorbed power = 13.14 W-Xsec area of heated volume = 484 mm^2-Cu conductivity = 391 W/m-K-Cu density = 8.9 g/cc-Cu C = 0.385 J/g-degC-Emissivity = 0.4-Mass = 0.94 kg


Case 3: Copper block results

Steady state temps Transient temp at corner

295

315

335

355

375

395

415

435

455

0 2 4 6 8 10

Time (hr)

Tem

p a

t co

rner

(K

)

443K


Case 4: Copper block in Macor-Cu emissivity = 0.5

Macor features:-Power deposition = 0.46 W/mm-Absorbed thickness = 12 mm-Absorbed power = 5.52 W-Xsec area of heated volume = 484 mm^2-Macor conductivity = 1.46 W/m-K-Macor density = 2.52 g/cc-Macor C = 0.79 J/g-degC-Emissivity = 0.5-Mass = 0.32 kg

97.2 mm

86.2 mm33 mm

Macor

Cu

View with half ofMacor not shown

Isometric view


Case 4

Steady state temps


Case 4: Transient results

295

345

395

445

495

545

0 5 10 15

Time (hr)

Te

mp

(K

)

Cu center

Cu corner

M acor center

M acor corner

402K

477K

513K


Case 5: Simplified geometry Cu+Macor+SS

SS features:-Power deposition = 0.798 W/mm-Absorbed thickness = 64.08 mm-Absorbed power = 51.1 W-Xsec area of heated volume = 484 mm^2-SS conductivity = 16.3 W/m-K-SS density = 8 g/cc-SS C = 0.5 J/g-degC-Emissivity = 0.5-Mass = 11.5 kg

Front sectional view(plane normal to beam) Side sectional view

Overall width=95 mmCavity width=88 mm

Overall height=234 mmCavity height=183 mm

Overall depth=98 mmCavity depth=45 mm

SS

Macor

Cu

3D view



Tin melts

295

345

395

445

495

545

595

0 2 4 6 8 10

Time (hour)

Te

mp

era

ture

(K

)

Cu centerCu cornerMacor centerMacor cornerSS centerSS corner

322 degC

272 degC

222 degC

172 degC

122 degC

72 degC

22 degC

SS center

SS corner

Macor corner

Macor center

Cu cornerand center

565K

555K

482K

438K

409K



295

345

395

445

495

545

595

645

695

0 2 4 6 8 10

Time (hour)

Te

mp

era

ture

(K

)


Emissivities:Cu = 0.7Macor = 0.25SS = 0.25

644K

641K

567K

492K

463K



Emissivities:Cu = 0.7Macor = 0.75SS = 0.7

295

345

395

445

495

545

0 2 4 6 8 10

Time (hour)

Te

mp

era

ture

(K

)


511K

510K

442K

415K

387K


Case 8: Simplified geometry Cu+Macor+SS, 4 foot aluminum bar attached

295

345

395

445

495

545

0 2 4 6 8 10

Time (hour)

Tem

per

atu

re (

K)

Cu centerCu cornerMacor centerMacor cornerSS centerSS cornerAl@SS endAl@opposite end

Emissivities:Cu = 0.7Macor = 0.75SS = 0.7Alum = 0.7

495K

415K

377K

323K

310K


295

345

395

445

495

545

0 2 4 6 8 10

Time (hour)

Tem

per

atu

re (

K)


Case 11: Simplified geometry Cu+Macor+SS, 4 foot aluminum bar attached,

with free convection


488K

407K

359K

312K

303K


295

345

395

445

495

545

595

645

0 2 4 6 8 10

Time (hour)

Tem

per

atu

re (

K)


Case 12: Simplified geometry Cu+Macor+SS, 4 foot aluminum bar attached,

with free convection


612K

517K

367K

315K

304K


295

345

395

445

495

545

595

645

0 2 4 6 8 10

Time (hour)

Tem

per

atu

re (

K)


Case 13: Same as 12, but with new beam loading values


620K

520K

372K

316K

304K


Comparison 1

Power deposition (W/mm):Cu = 0.876Macor = 0.460SS = 0.798

Steady State Temps for different emissivitiesCopper inside Macor inside Stainless housing

100

150

200

250

300

350

400

(#7) Cu emis=0.7, Macor emis=0.75, SSemis=0.7



Te

mp

era

ture

(d

eg

C)

copper

Macor center

Macor corner

Stainless center

Stainless corner


Comparison 2 EmissivitiesCu = 0.7Macor = 0.75SS = 0.7Al = 0.7


Steady State Temperatures for different conditions

0

50

100

150

200

250

(#7) without aluminum bar,no convection

(#8) with aluminum bar, noconvection

(#11) with aluminum bar,free convection

Tem

per

atu

re (

deg

C)

copperMacor center

Macor corner

Stainless center

Stainless corner

Aluminum end

August 21, 2003 22

Comparison 3: Steady State Temps for Different Conditions



0

50

100

150

200

250

300

350

(#11) Cu emis=0.7, Macoremis=0.75, SS emis=0.7, Al

emis=0.7


emis=0.7


emis=0.7

Tem

per

atu

res

(deg

C)

copper

Macor center

Macor corner

Stainless center

Stainless cornerAluminum end

August 7, 2003K. Chow, LHC Luminosity Detector Thermal Analysis1 Analysis cases Approach: Start...

Documents

Transcript of August 7, 2003K. Chow, LHC Luminosity Detector Thermal Analysis1 Analysis cases Approach: Start...