www.bristol.ac.uk/composites A design concept for an adaptive, variable geometry fluid inlet is presented. The inlet’s shape adapts passively in response to varying flow conditions. In contrast to traditional designs, the inlet does not rely on separate mechanisms for actuation. Instead, the novelty of the present approach is that a variety of adaptive responses are obtained by exploiting the nonlinear behaviour of post-buckled structures. Adaptive structures for fluid flow regulation Gaetano Arena, Rainer Groh, Raf Theunissen, Paul Weaver & Alberto Pirrera Supported by Coupled Eulerian-Lagrangian (CEL) fluid-structure interaction Adaptive inlet with monostable snap-through behaviour 1) Open stable state 2) Snap-through occurs once a critical velocity is reached 3) Unstable closed state 4) Suction holds the inlet in its closed state. I N T E R A C T I O N F L U I D Abaqus solves the Equation of State (EOS), plus the continuity and momentum equations. p=pressure; p H =Hugoniot pressure; Γ=Grüneisen ratio; E H =Hugoniot specific energy; e=internal energy; ρ=density; v=velocity; f=body forces, σ=Cauchy stress tensor=-pI+σ dev . Precompression Adaptive behaviour through nonlinear structural mechanics Influence of pre-compression and pre-bending (1) on a post-buckled beam (2). When symmetry is broken (broken pitchfork), regions of bistability (3), monostability with snap-through behaviour (4) and simple monostability are identified. Central displacement (1) (2) (3) (4) Bistability S T R U C T U R E Monostability with snap- through behaviour Simple stability Force Snap-through Unloading path 0 Central displacement Force Snap-through Unloading path 0 Applications

Adaptive structures for fluid flow regulation

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Page 1: Adaptive structures for fluid flow regulation

www.bristol.ac.uk/composites

A design concept for an adaptive, variable geometry fluid inlet is presented. Theinlet’s shape adapts passively in response to varying flow conditions. In contrast totraditional designs, the inlet does not rely on separate mechanisms for actuation.Instead, the novelty of the present approach is that a variety of adaptive responsesare obtained by exploiting the nonlinear behaviour of post-buckled structures.

Adaptive structures for fluid flow regulation

Gaetano Arena, Rainer Groh, Raf Theunissen, Paul Weaver & Alberto Pirrera

Supported by

Coupled Eulerian-Lagrangian (CEL) fluid-structure interaction

Adaptive inlet with monostable snap-through behaviour

1) Open stable state 2) Snap-through occurs once a critical velocity is reached

3) Unstable closed state 4) Suction holds the inlet in itsclosed state.

INTERACTION

FLUID

Abaqus solves the Equation of State (EOS), plus the continuity and momentum equations.

p=pressure; pH=Hugoniot pressure; Γ=Grüneisen ratio; EH=Hugoniot specific energy; e=internal energy;ρ=density; v=velocity; f=body forces, σ=Cauchy stress tensor=-pI+σdev.

Precompression

Adaptive behaviour through nonlinear structural mechanics

Influence of pre-compression and pre-bending (1) on a post-buckled beam (2). When symmetry is broken (broken pitchfork), regions of bistability (3), monostability with snap-through behaviour (4) and simple monostability are identified.

Centr

al dis

pla

cem

ent

(1)

(2) (3)

(4)Bistability

STRUCTURE

Monostability with snap-through behaviour

Sim

ple