conatus.problems.taylor_couette_evp¶
- conatus.problems.taylor_couette_evp(*, N, Re, eta, mu, m, k)[source]¶
Linear stability of circular Couette flow: normal modes exp(i m phi + i k z + s t) of the equations of
taylor_couette()(same units, u = 0 on both cylinders).Eigenvalue s = growth rate + i frequency. Only
plan.group(m, k)is meaningful: phi and z bases are ComplexFourier of sizes 2|m| + 4 and 4 (structural), z period 2 pi / k; AnnulusBasis(r, N), dealias 1 (linear; U0 = A r + B/r is resolved to round-off by the NCC expansion, see the plan’s NCC report).Validation reference: eta = 0.5, outer cylinder at rest (mu = 0), axisymmetric modes: Re_c = 68.19 at k_c = 3.16 (Recktenwald, Luecke & Mueller 1993, Phys. Rev. E 48, 4444, Table I). Tutorial t08 finds 68.19 with N = 24 (tests/problems/test_problems_cylinders.py).
- Parameters:
N (int)
Re (float)
eta (float)
mu (float)
m (int)
k (float)
- Return type: