question about the inertial term expression in Navier-Stokes equation

Hi all,

I have a question about the inertial term expression in COMSOL.

As we know, the inertial term in Navier-Stokes equation is rho*u*del(u), rho is density, u is velocity vector.

While in COMSOL, the inertial term is written as rho*(u*del)u.

These two expressions are different.

Is there something wrong with the expression in COMSOL?

I am very appreciated that if you can answer my question.

Many thanks,

John