Steady-state Bifurcations of the Three-dimensional Kolmogorov Problem

Abstract

This paper studies the spatially periodic incompressible fluid motion in ℝ3 excited by the external force k2 (sin kz,0,0) with k ≥ 2 an integer. This driving force gives rise to the existence of the unidirectional basic steady flow u0 = (sin kz,0,0) for any Reynolds number. It is shown in Theorem 1.1 that there exist a number of critical Reynolds numbers such that u₀ bifurcates into either 4 or 8 or 16 different steady states, when the Reynolds number increases across each of such numbers.

Thanks to the Rabinowitz global bifurcation theorem, all of the bifurcation solutions are extended to global branches for λ ∈ (0, ∞). Moreover we prove that when λ passes each critical value, a) all the corresponding global branches do not intersect with the trivial branch (u0, λ), and b) some of them never intersect each other; see theorem 1.2.