E-Conference August 13 and 15, 2002

APEX Task 3c: Divertor IntegrationSNL, ORNL, UCLA , ANL, others Richard Nygren, leader/presenter

Export Control: GTDA General Technical Data No Export Control License Required

Contributors:Brad Nelson, Paul Fogarty (ORNL)Sergey Smolentsev (UCLA)Tom Rognlien, Marv Rensink, Dick Bulmer (LLNL)Dick Majeski (PPPL)TK Mau, Clement Wong (GA)Jeff Brooks, Ahmed Hassenien (ANL)Dai Kai Sze (UCSD)Mike Ulrickson, Dennis Youchison , Bob Bastasz, Don Cowgill, (SNL)Richard Nygren, leader (SNL)

E-Conference August 13 and 15, 2002

Deflected stream option (FW flow)• Divertor configuration• Heat removal• Pumping/Drain• Outstanding issues (RF system, surface waviness, ..)• Report (draft circulated for comment)

Progress - August 2002

For November Meeting 2002• Divertor configuration with CAD drawings• Pumping for parallel stream or droplet concepts• RF system layout for divertor cassette• Report and paper on ARIES/CLIFF/Flinabe

Task 3 Divertor Integration

Divertor Configuration

Deflected stream option (FW flow)

• Utilized decay of turbulence per Sergey

• Refined specifications for target location

• Working to integrate preferred location

• Review the rationale for deflected stream

• Show impact of enhanced keff (turbulence)

• Show mechanical design in progress (CAD drawings by PJ Fogarty)

• List current issues to be resolved Opt1 FW flow divertor

deflected flow

“sheet”

deflecters

0.2

0.4

0.6

0.8

1.0

1.2

0 30 60 90target rotation (degrees)

T-r

ise

fact

or1

loc 1loc 2loc 3

flxp1factorT /)sin(

v

flxpLt

)sin(0

kvflxpC

LqT

prisesurf

1)sin(* 0

,

t

k

qT risesurf

, with Portion of

Roglien /Bulmer (LLNL) flux map for ARIES-RS with a single null divertor

-4.5

-4.4

-4.3

-4.2

-4.1

-4.0

-3.9

-3.8

-3.7

-3.6

-3.5

-3.4

-3.3

-3.2

-3.1

-3.0

-2.9

-2.8

-2.7

-2.6

-2.5

4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2z(

m)

z0

z1

z2

z3

z4

z5

z7

deflector

1

2

3

R(m)

Strike point positions

1, 2 3

Divertor ConfigurationSimple dependence on angle and flux

expansion presented previously.

At an angle >40°, T-factor1 is lowest for Pos. 1.

Position 3 has lowest possible angle.

Decaying turbulence of free surface vs. distance from the deflector Smolentsev calculation (red)equation (3.7+33.8exp[-x/0.14] overlaid (aqua)

0

10

20

30

40

0.0 0.2 0.4 0.6 0.8 1.0

flow length (m)

nu

-ra

tioImpact on Design:

Strike point must be 15cm or less from the deflector

The closer to the deflector, the higher the effective thermal conductivity in the

>1mm layer below the free surface.

y

x

10 m/s = v0 (fully dev. turbulent profile)

2.3cm = initial flow thickness 10T = magnetic field (spanwise) 62= inclination 1m = flow length (downstream of nozzle outlet)

0 0.2 0.4 0.6 0.8 1y / h

0

20

40

60

80

Nyu

_t

/ Nyu

Turbulent v iscosity across the layer

1: x=0.1 m2: x=0.2 m3: x=0.4 m4: x=0.6 m5: x=1 m

1

2

3

4

5

0 0.2 0.4 0.6 0.8 1D istance, m

0

10

20

30

40

(Nyu

_t /

Nyu

) surf

ace

y

x

v0

Sergey’s model

Model by Smolentsev

(UCLA)

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.00 0.10 0.20 0.30 0.40 0.50 0.60

turbulent decay length (m)

T-f

act

or2

(a

rb)

P1-39deg

P2-20deg

P2-27deg

P2-32deg

P2-53deg

P3-11deg

P3-27deg

P3-36deg

P3-53deg

P3-81deg

effkflxpfactorT

*

)sin(2

-4.5

-4.4

-4.3

-4.2

-4.1

-4.0

-3.9

-3.8

-3.7

-3.6

-3.5

-3.4

-3.3

-3.2

-3.1

-3.0

-2.9

-2.8

-2.7

-2.6

-2.5

4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2

z(m

)

z0

z1

z2

z3

z4

z5

z7

deflector

1

2

3

R(m)

Divertor Configuration

Include turbulent decay in T-factor.

Portion of Roglien /Bulmer (LLNL) flux map for ARIES-RS with a single null divertor

ARIES-RS SN outer div. flux map (Rognlien/Bulmer, LLNL)

-4

-3.5

-3

-2.5

-2

4.5 5 5.5 6 6.5

R(m)

z(m

)

z0

z3

z7

z12

z15

Three options for flow path that minimized distance between end of deflector and strike point.

1. FW flow at lower position 2. Long deflector3. Multiple (2 or 3) deflectors

A single small deflector is simplest.

A long deflector keeps the FW flow along the same flux surface but requires a large surface area of structure.

Multiple deflectors gives a more complex arrangement but may help move flow toroidally to cover the exit flow around the RF ports and guide flow to create openings for pumping.

Divertor Configuration

Divertor Configuration

Deflector for strike point Position 2 (majenta line in previous figure)

Views of “sled” for divertor cassette. CAD Drawings by PJ Fogarty (ORNL)

16x16” folded wave guide

Vanes support deflector and also guide flow

Deflector

Pumping and Drain

DT fueling + D puffing - burn/2 - deposition defines exhaust pumping needed.

pumping entrances

He/(D+T)

Pumping is adequate. Work continues on novel concepts to pump He.

Space for drain is adequate.

Splashing where divertor streams join has not been evaluated. This might be done by CFD model or/and experiment.

CAD Drawings by PJ Fogarty

(ORNL)

Location of the RF Systems

• Housed in the divertor cassette if possible

• LH current drive needs proximity to plasma

• ECH needs waveguides and mirrors

Draft tech. note on divertor functions (july02)

Dick Majeski quickly responded. (Thanks)

Majeski/Nelson/Fogarty are defining the requirements (power, area, …)

Surface Waviness

• Sergey’s work indicates enhanced k of ~X2

• Richard’s hot spot analysis indicates locally peaked heat loads

Richard will develop evaluation of effect of multiple hot spots.

Divertor Integration Issues

ECH waveguides & mirror (3)

LH folded wave guide

CAD Drawings by PJ Fogarty

(ORNL)

Flow model of divertor flow and drain

• CFD2000 models of heat load on flat Li stream (Youchison) and Li flow from high compression nozzle (Brantley)

• CFD models are needed

a. flow around RF penetration

b. flow through deflector/vanes

c. flow in duct (joining streams)

Richard will model drain. (Developer had problem here.)

Documentation Overdue

• Report (draft circulated)

Richard will write report & paper.

Divertor Integration Issues

FW flow

deflector

Inner

div. flow

duct

q”div

Flow Modeling with CFD2000

CFD2000 3-D model of Li stream with applied heat flux by Dennis Youchison (Sandia)

Depth of engineering Details for Design Integration

• Approach A: more options, less in-depth engineering

• Approach B: fewer options, more in-depth engineering

We should pause to consider our approach in FY03.

Divertor Integration Issues

We need to discuss whether(a) we CAN do adequate design integration (resource issue) and(b) we WILL do adequate design integration (our commitment).

a. time on detailed design & engineering specifications

b. resources and scheduled time for design analysis

c. frequent interaction to resolve issues in design integration

Richard’s evaluation: Task 3 was heavier on engineering in our first couple of years and lighter during FY02.