
1094 SYSTEMS OF LINEAR PARTIAL DIFFERENTIAL EQUATIONS
◮ Decomposition not requiring the mass force to split into components (the fi rst ap-
proach).
The solution of Eqs. (1) of viscoelastic fluids can be represented in the form
u = −curl curl U ≡ ∆U −∇div U, p = p
0
(t) + L[div U],
where p
0
(t) is an arbitrary function and the vector function U satisfies the equation
∆L[U] = f.
◮ Decomposition not requiring the mass force to split into components (the second
approach).
The solution of Eqs. (1) of viscoelastic fluids can be represented in the form
u = ∆U + ∇
ϕ −(LH + 1)[div U]
, p = p
0
(t) − ρL
ϕ − (LH + 1)[div U]
,
where p
0
(t) is an arbitrary function, H is