Updated TMM of the CLIC Two-Beam Module (old) and T0 in the LAB

Riku Raatikainen

15.8.2011

Part I: Updated version of the existing (old) TMM Introduction

- Load conditions- Cooling concept

Model description Results

Conclusion

Part II: TMM of CLIC Two-Beam Module (LAB) Introduction

- Load conditions- Cooling concept

Model description Results

Discussion

INDEX

Part I: Updated version of the existing (old) TMM

Thermo-Mechanical Model (TMM) motivation

During operation, the CLIC module is exposed to variable high power dissipation while the accelerator is ramped up to nominal power as well as when the mode of the CLIC operation is varied

As a result, this will cause inevitable temperature excursions driving mechanical distortions in and between different module components → FEM model is essential to facilitate its design

Based on the simplified TMM, the upgraded model has been under development

Upgrading the TMM is done in two steps:

1. Studying the influence of the DB QP magnets to the previous TMM (with internal cooling)2. New TMM is generated on the basis of the current module layout and the results obtained

from the 1st step

Previous TMM. Note that the DB QP magnets were omitted from the model.

Load condition

The aim of the TMM is to study how the module deforms as a whole because of applied loads (temperature variations, vacuum conditions Δp = 1 bar, gravity)

Accelerator’s performance is strongly coupled with temperature

CLIC Module component thermal dissipations can be divided into sections:

87%

4%1% 8%

CLIC Module T0 average thermal dissipations of each component (unloaded operation)

AS PETS WG DB QP

AS dissipation 411 W (unloaded), 336 W ̴ ̴(loaded)PETS dissipation 39 W (110 W reserve) ̴DB QP Magnet 150 W ̴Waveguide dissipation 11 W ̴

Cooling concept

Module cooling is executed using water flow (inlet temperature 25 °C)

Item Description Value

MB input flow mass flow 68.6 kg/h

PETS+WG mass flow 37.4 kg/h

DB QP Magnet Mass flow 25 kg /h

HTC MB Convection to water 3737 W/(m2·K)

HTC PETS+WG Convection to water 1407 W/(m2·K)

HTC DB QP Convection to water 1582 W/(m2·K)

HTC air Convection to air 4 W/(m2·K)

Cooling boundary conditions; HTC: heat transfer coefficient.

PETS x 4

T

Sup

ply

pipe

Ret

urn

pipe

CV

CV

CV = control valveT = temperature sensor

T T

Super-AS

TCV

Super-AS

TCV

Super-AS

TCV

Super-AS

TCV

WG x 4

EDMS ref. 1110100 v.1

Model description

The existing CLIC module was resolved with the DB QP so that internal cooling was taken into account.

The model was solved for unloaded operation mode only with gravity, vacuum and RF included showing the baseline of the thermo-mechanical behavior with DB QP magnets (connected to DB girder and partially to DB line). The rest of the model was kept same in order to see the direct influence of the magnets and moreover, the model had to be resolved only for once.

For more precise information of the previous module FEA can be found in EDMS e.g. 1110100 v.1 (supports, contact modeling etc.)

Illustration of the CLIC module (old) with the DB QP magnets

Results

Temperature distribution of the module.

Water outlets (inlet 25 °C):

→ SAS 35 °C→ PETS+WG 29.8 °C→ DB QP 35 °C

Displacement of the DB side

Illustration of the force reaction on the interconnection point; magnitude of the force is 2 N

Item Old value New value Difference

Max. temp. of MB 41°C 41°C -

Max. temp. of DB 32°C 39°C* 7 °C

Max. def. at DB girder 30 µm 60 µm 30 µm

Max.def. at DB line 26 µm 28 µm 2 µm

Force reaction; DB drift tube-DB QP

magnet 2.14 N 2.15 N -

Overview of the results in case the QP magnets are included to TMM.

* Max. coil temperature

Results

Conclusion

The effect of the magnets is seen primary when then gravity is included to the model

Since the coils of the DB QP magnets are thermally insulated from the magnet poles, the temperature difference in the coils does not have an impact to the DB drift tube → For a good reason the DB QP magnets can be included to the future TMM without taking into account their thermal dissipation or cooling (just notifying the mass). In addition the DB QP is solidly mounted on the DB girder where PETS and BPM are affected by single thermal load.

If detailed study for the DB QP magnets are in order, this can be done separately. Moreover, current TMM such as the lab module is significantly heavier in computational view and including DB QP cooling modeling into a such model would increase the computation time even more. The aim of the large TMM should focus on the RF structures.

Much better approach taking into account any thermal variations within the magnets in TMM is to apply temperature increment directly to the desired hot spot (e.g. coils). The temperature variation of the coils is determined by the manufacture.

Part II: TMM of CLIC Two-Beam Module (LAB)

TMM was implemented to the CLIC Two-Beam module to be tested in the lab (Type 0)

As a first step, the FEM TMM had to be re-assembled to correspond current layout (including significant geometrical simplification to the 3D design, ST0312798_01)

After the simplification, the geometry was imported to ANSYS

Fluid network generation was done in parallel with CATIA and ANSYS

Overview

3D model of the CLIC Test module in the lab (Type 0 – Type 0) - Courtesy of D.Gudkov

PETS

AS

AS support

MB girder

PETS support

DB QP

DB cradle and movers; DB girder

MB cradle and movers

Vacuum reservoir

Vacuum spider network

Waveguide

Current TMM geometry configuration

DB Q DB Q

410 W410 W 410 W 410 W 410 W410 W 410 W 410 W

110 W110 W 110 W110 W150 W 150 W

EDMS 1097388

Loading condition

In the lab no cooling is applied to the DB QP → shown thermal dissipation is suggestive and to be used only to heat up the magnets

In the lab the aim is to create an environment close to the unloaded operation of the CLIC module. Thus, for example, the PETS are heated up to 110 W (maximum reservation)

CLIC Test Modules - Meeting #44

Cooling concept (LAB)

Item Description Value

MB input flow mass flow 68.6 kg/h

PETS+WG mass flow 37.4 kg/h

HTC MB Convection to water 5079 W/(m2·K)

HTC PETS+WG Convection to water 1407 W/(m2·K)

HTC air Convection to air 4 W/(m2·K)

Cooling boundary conditions; HTC: heat transfer coefficient.

BOOSTEC

MC

Master

Slave

Slave

Master

Adjacent girders will be interlinked with their extremities (so called cradle), allowing a movement in the transverse girder interlink plane within 3 degrees of freedom (X, Y, roll)

The ANSYS modeling was done to the level of the mounting surface of the actuator lower ends → As a results the estimated vertical and lateral stiffness of the actuator support was taken into account – both master and slave cradle end design were introduced to the model (Thanks to M. Sosin)

Modeling Highlights - Supports

Actuator stiffness was reduced to equal stiffness linear and torsional springs

Master and slave supporting system in the lab (Type 0)

Modeling Highlights – Contact modeling

Contact and joint modeling includes flexible joint and standard ANSYS component bonded connections. Flexible joints can be defined analytically as a stiffness matrices. All the module subsystems are thermally coupled (perfect thermal conductance)

All contact modeling aimed at the lightest possible computation because of overall contact and joint number is in the magnitude of several hundred

Contact and joint modeling illustration

Stiffness matrix definition for the contacts. Note that ANSYS allows also damping coefficients as a direct input

Modeling Highlights – Meshing options

The ANSYS meshing had to be adjusted and optimized and several different configurations were implemented

The current mesh includes hexa and tetrahedral methods, element size control settings, Sweep, contact sizing etc. in order to achieve fine and appropriate mesh for the coupled field simulation. The mesh is highly relevant between the contact surfaces and interconnection areas where the fluid flow interacts with the solid structure (convectional area)

At the moment the model includes approximately 4.9 million nodes. The coupled FLUID116 element is the driving parameter to the fluid-thermal results

Solution time for the whole model takes several with a virtualremote Engineering PC

Created mesh for the lab module in ANSYS Workbench 13.0

Results

Temperature distribution within the module. The highest surface temperatures are in magnitude of 42 °C; on the internal beam surfaces the temperature could rise up to 44 °C

Results

The water temperature rise is approximately 10 °C as shown.

Conclusion

The thermal results show that during the heating ramp up the temperature of the module rises over 40 °C. The highest temperature variations occur on the inner beam surfaces where the heaters are located.

The water temperature rise is 10 °C and the variation to the heat balance is less than 1 %. Though the thermal results can be considered reliable. Unlike with PETS average dissipation of 39 W, the 110 W thermal dissipation will drive the PETS and AS temperature closer to each other.

Structural results under calculation…the current model has converged only when using simplified structural boundary conditions…

As a upcoming actions the TMM is applied to the CLIC module Type 0 with a both operation modes – unloaded and loaded – included. On basis of the new TMM geometry created for the lab module, different modules can be analyzed by modifying the current lab TMM module.