“…Let P be the Helmholz‐Leray orthogonal projection in ( L 2 (Ω)) 2 onto the space H . The bilinear operator B (·,·) and trilinear operator b (·,·,·) are defined as (see Foias et al, Temam, Yang et al, Zhao and Caraballo, Zhao and Yang, Zhao et al, and Zhao and Duan) which satisfy in 2‐D …”