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gtspring2009:research_projects [2009/03/10 08:34]
wikiadmin
gtspring2009:research_projects [2009/07/08 08:29]
gibson
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   - Search for **new relative equilibria** (traveling waves). In particular, currently we have no relative equilibrium that travels both streamwise and spanwise.   - Search for **new relative equilibria** (traveling waves). In particular, currently we have no relative equilibrium that travels both streamwise and spanwise.
   - Search for **new heteroclinic connections**,​ particularly connections to solutions with greater than 1d unstable manifolds. Get a start on this by expanding the existing heteroclinic connections. The EQ4 to EQ1 connection can be extended to a 2d sheet by perturbing along a third real-unstable S-symmetric eigenfunction. Could also explore the possibility of hitting the different translational phases of the EQ1  from EQ4 by perturbing the  existing heteroclinic connection with S-antisymmetric eigenfunctions. ​   - Search for **new heteroclinic connections**,​ particularly connections to solutions with greater than 1d unstable manifolds. Get a start on this by expanding the existing heteroclinic connections. The EQ4 to EQ1 connection can be extended to a 2d sheet by perturbing along a third real-unstable S-symmetric eigenfunction. Could also explore the possibility of hitting the different translational phases of the EQ1  from EQ4 by perturbing the  existing heteroclinic connection with S-antisymmetric eigenfunctions. ​
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 ==== Other open projects ==== ==== Other open projects ====
  
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   - Look at state-space structure as a function of Reynolds number, starting from our current state-space portraits and heteroclinic connections. Can we understand transient lifetimes as a function of Reynolds from changes in state space structure?   - Look at state-space structure as a function of Reynolds number, starting from our current state-space portraits and heteroclinic connections. Can we understand transient lifetimes as a function of Reynolds from changes in state space structure?
   - Related to above, try to understand via state-space structure why turbulent lifetime increases dramatically when Lz goes from <​latex>​ 1.2 \pi </​latex>​ to <​latex>​ 1.75 \pi </​latex>​   - Related to above, try to understand via state-space structure why turbulent lifetime increases dramatically when Lz goes from <​latex>​ 1.2 \pi </​latex>​ to <​latex>​ 1.75 \pi </​latex>​
 +  - 2009-07-08 **Try to find //​near-wall//​ solutions**. Basic idea is to add a pressure gradient to plane Couette flow to break the sigma_x symmetry and make the mean flow profile look more like the mean flow profile in the near-wall region of a turbulent channel flow. That would give you pseudo boundary layer solutions (i.e. solutions that roughly fit the mean-flow profile of a boundary layer, but have a Dirichlet boundary condition on the upper surface). Then you rachet up the Reynolds number and pressure gradient in order to make the total domain larger and larger, relative to the near wall region. Eventually you have solutions living in the high-gradient near-wall region of a boundary layer, with the Dirichlet boundary condition far away. I will write this up with plots soon. //John Gibson 2009-07-08 11:27 EST//
  
 ===== Hiccups ===== ===== Hiccups =====
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