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Classification of FSI algorithms
• Purely geometrical methods, based only upon topology of
the F-S interface in the vicinity of node under consideration:
FSA algorithm (Fluid-Structure ALE)
• Non-geometrical methods, based upon equilibrium
considerations:
UP algorithm (Uniform Pressure)
• Hybrid methods:
FSCR algorithm
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The FSA algorithm
• Purely geometrical method, based upon local shape of fluid domain
only (avoids ambiguities due to no-thickness structural elements).
• Normal direction obtained from
zero net velocity flux condition
across discrete interface (no
fluid gains or losses):
∆
influence domain of node
n =∆/ ∆ with ∆=∑ S
k = 1
n
k
• The 2-D plane case:
n
S L n
2 2 2
n = ( S + S )/ S + S
1 2 1 2
S Ln
1 1 1
L 2
S
2
n
y
L 1
Fluid
S 1
x
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