Numerical Methods for the Navier–Stokes Equations
Published in Dale A. Anderson, John C. Tannehill, Richard H. Pletcher, Munipalli Ramakanth, Vijaya Shankar, Computational Fluid Mechanics and Heat Transfer, 2020
Dale A. Anderson, John C. Tannehill, Richard H. Pletcher, Munipalli Ramakanth, Vijaya Shankar
The use of central differences results in a five-point stencil. The stencil for point (i, j) is split into three components. Stencil components below the diagonal from points (i − 1, j) and (i, j − 1) are collected into the matrix [L] (see Figure 9.2). Stencil components on the diagonal (from points (i, j), (i − 1, j + 1), and (i + 1, j − 1) are collected into matrix [D]. Stencil components above the diagonal (from points (i, j + 1) and (i + 1, j) are collected into matrix [U]. Thus, [A˜] is represented by [L˜]+[D˜]+[U˜], and our matrix–vector representation of Equation 9.81 becomes
([L˜]+[D˜]+[U˜])Δqn+1=−R