  Coarse grid projection (CGP) multigrid techniques are applicable to sets of
equations that include at least one decoupled linear elliptic equation. In CGP,
the linear elliptic equation is solved on a coarsened grid compared to the
other equations, leading to savings in computations time and complexity. One of
the most important applications of CGP is when a pressure correction scheme is
used to obtain a numerical solution to the Navier-Stokes equations. In that
case there is an elliptic pressure Poisson equation. Depending on the pressure
correction scheme used, the CGP method and its performance in terms of
acceleration rate and accuracy level vary. The CGP framework has been
established for non-incremental pressure projection techniques. In this
article, we apply CGP methodology for the first time to incremental pressure
correction schemes. Both standard and rotational forms of the incremental
algorithms are considered. The influence of velocity Dirichlet and natural
homogenous boundary conditions in regular and irregular domains with structured
and unstructured triangular finite element meshes is investigated. $L^2$ norms
demonstrate that the level of accuracy of the velocity and the pressure fields
is preserved for up to three levels of coarsening. For the test cases
investigated, the speedup factors range from 1.248 to 102.715.
