The Dual Reciprocity Method (DRM) is a technique to transform the domain in
tegrals that appear in the boundary element method into equivalent boundary
integrals. In this approach the non-linear terms are usually approximated
by mathematical interpolation applied to the convective terms of the form o
f the Navier-Stokes equations. In this paper we introduce a conservative in
terpolation scheme that satisfies the continuity equation and performs bett
er than pure mathematical interpolation. The new scheme together with a sub
domain variation of the dual reciprocity method allows better approximation
of the non-linear terms in the Navier-Stokes equations for moderate Reynol
ds number.