The example of Rayleigh-Benard convection
Pattern-forming instabilities: The example of Rayleigh-Benard convection
Rayleigh-Benard convection. Boussinesq approximation, incompressible flow
Rayleigh-Benard convection. Boussinesq approximation, incompressible flow
Rayleigh-Benard convection. Boussinesq approximation, incompressible flow
Rayleigh-Benard convection. Boussinesq approximation, incompressible flow
Rayleigh-Benard convection: static state
Rayleigh-Benard convection
Rayleigh-Benard convection: static state with pure conduction Fixed temperature b.c.
Rayleigh-Benard convection. Boussinesq approximation, incompressible flow
Rayleigh-Benard convection: non dimensional formulation
Rayleigh-Benard convection Important parameters: R = g D 3 T 2 -T 1 ) / = a = L D
Rayleigh-Benard convection. If R < R crit conduction T(x,y,z,t)=T cond (z)=T 2 - z (u,v,w)=(0,0,0) If R > R crit convection T= T cond + (u,v,w) non zero
Rayleigh-Benard convection. Linear stability analysis
2D Rayleigh-Benard convection (non dimensional formulation)
2D Rayleigh-Benard convection
2D Rayleigh-Benard convection: Linearization around the static state
2D Rayleigh-Benard convection: Linearization around the static state
2D Rayleigh-Benard convection: Linearization around the static state
2D Rayleigh-Benard convection: Linearization around the static state
2D Rayleigh-Benard convection: Linearization around the static state
Rayleigh-Benard convection. Linear stability analysis
2D Rayleigh-Benard convection: Threshold to convection
Rayleigh-Benard convection: above R crit, convective motion occurs. This takes the form of parallel rolls
The convective rolls saturate the instability
Amplitude expansion
Amplitude expansion: first order
Amplitude expansion: second order
Amplitude expansion: third order
Amplitude expansion: third order The Fredhom alternative: eliminate the secular term and get a solvability condition: The Landau equation
Amplitude expansion: third order The Landau equation with real coefficients
Pitchfork bifurcation at R 2 =0
Stability of the rolls: Busse balloon
Stability of the rolls