Uniform energy bounds for the forced regularized solutions #
lem:forced-energy-bounds: the forced energy inequality eq:reg-energy-forced
with 2 f·u ≤ |f|² + |u|² and Grönwall's inequality bound the kinetic energy
on [0,T] by E_T = e^T (‖a‖₂² + ‖f‖²_{L²((0,T)×ℝ³)}), and substitution back
into the same inequality bounds the dissipation on (0,T) by
G_T² = (‖a‖₂² + ‖f‖²_{L²((0,T)×ℝ³)} + T E_T) / 2. Both constants are
independent of the regularization parameter.
lem:forced-energy-bounds: a velocity with continuous L² slices, a
square-integrable weak gradient on finite slabs and the forced energy
inequality eq:reg-energy-forced satisfies, on every [0,T], the kinetic
bound ‖u(t)‖₂² ≤ E_T and the dissipation bound 2 ∫₀ᵀ ‖Du‖₂² ≤ 2 G_T²,
with E_T and G_T depending only on T, ‖a‖₂ and the L² norm of f
on (0,T).