“…The velocityāpressure finite element spaces are characterized by a uniform triangulation
(here,
or
) with the quadratic equalāorder finite elements pair. In our numerical tests, an attractive feature is that the projection
is computed by using the firstāorder Gauss integration
over the element
, avoiding the construction of the projection operator
(noting that,
is equivalent to
as stated in Zheng and Shang
38 ).…”