Exploratory study of blanket liquid curtain

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Exploratory study of blanket liquid curtain

• Hu Gang

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Motivation and Background

• Motivations
• High capability of heat removal and
  self-refreshing
• Reduced radiation damage in structural materials
• Potential for higher availability
• Background
• Design of flowing liquid curtain for blanket in
  fusion reactors
• Concept design of Compact Fusion Experimental
  Reactor-Spherical Tours (CFER-ST)
• ALPS and APEX Programs

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Method of solution

• Developing calculation code based on ANSYS
• Solution of MHD effects can be achieved by
  action of induced electro-magnetic forces on the
  fluid
• key problems electro-magnetic analysis of
  fluid, multi-physical analyses, loop control,
  convergence conditions and other factors
• Calculating and analyzing properties of liquid
  curtain
• Key problems effects of induced electrical
  and magnetic fields, distribution of velocities,
  properties of liquid curtain

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Model of electromagnetic analyses of liquid metal
flows
(a)small cut volumes of metal flow
(b)small cut volumes on a z plane
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Loop control diagram of the new calculation code
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Notice while programming

• During multi-physical analyses, physical
  environments, physical quantities, nodes and
  elements of two parts should be correlated.
• Balance condition is that distribution of
  velocities can only result in this distribution
  of electromagnetic forces and on the other hand
  under such distribution of forces only exists
  this distribution of velocities
• Convergence conditions and criteria under stable
  situations
• Simplification of calculation
• Programming should not beyond ANSYS.

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Optimum Input Data
relative magnetic permeability 1, electric
resistivity 7e-7ohm-m of walls
t1mm?t12cm?t23mm?h4t18cm initial speed
0.64m/s
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Velocity distributions
a) with no magnetic field b) with
external field 2T
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Induced electro-magnetic force
The induced force acted on fluid will be
influenced by B and induced E
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Induced magnetic field effect
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Induced electrical field effect
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Conclusions

• Calculation codes used for analyzing the
  properties of blanket liquid curtain were
  developed based on ANSYS.
• MHD effects of free-surface liquid lithium flow
  in the metal duct were analyzed.
• Induced electro-magnetic force can alleviate the
  acceleration effects of gravity to form stable
  liquid curtain in front of blanket
• Electric field effect should be concerned in
  analyses of blanket liquid curtain
• Blanket liquid curtain is two-stream liquid wall
  fast moving free surface layer and slowly
  moving layer behind it.

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Liquid metal wall diagram