Locally linear embedding for transient cylinder wakes

Understand

Reduced-order representations of an ensemble of cylinder wake transients are investigated.

• Locally linear embedding identifies a two-dimensional manifold with a maximum error of 1% from new snapshot data.
• This representation outperforms a 50-dimensional POD expansion from the same data and is not obtainable with cluster-based coarse graining of similar order.
• This manifold resolves the steady solution, the stability eigenmodes, the first post-transient POD modes, the intermediate vortex shedding structure as well as higher harmonics.