Abstract
In some pressure-based methods, inner iteration processes are introduced to achieve efficient solutions. However, number of the inner iteration is fixed as 2 or 4 for different computations. In this paper, a mechanism is proposed to control inner iteration processes to make the number of inner iterations vary adaptively with different problems. The adaptive inner iteration processes are used in viscous compressible flows. Results reveal that by introducing inner iteration processes, computational efficiency is highly improved compared with that of the solution without inner iteration. In addition, adaptive inner iteration solutions have better robustness than fixed inner iteration solutions.
Nomenclature | ||
= | Coefficient in the discretized equation | |
= | Surface area | |
b | = | Source term |
= | Time step | |
= | Pressure | |
= | Pressure correction | |
R | = | Gas constant |
= | Source term caused by pressure | |
= | Source term caused by velocity | |
T | = | Temperature |
= | Velocity components in the x- and y-directions | |
= | Cartesian coordinates | |
= | Under-relaxation factor | |
= | Nominal diffusion coefficient | |
= | Density | |
= | General variable | |
= | Time step | |
= | Volume |
Subscripts | ||
e, w, … | = | east, west face of a control volume |
E, W,… | = | East, West neighbor of the main grid point |
nb | = | Neighbours of the P grid point |
P | = | Grid point P |
Superscripts | = | |
′ | = | Correction field |
0 | = | Values from previous time step or previous outer iteration |
* | = | Values from intermediate calculation |
** | = | Final values at present time step or present outer iteration |
Nomenclature | ||
= | Coefficient in the discretized equation | |
= | Surface area | |
b | = | Source term |
= | Time step | |
= | Pressure | |
= | Pressure correction | |
R | = | Gas constant |
= | Source term caused by pressure | |
= | Source term caused by velocity | |
T | = | Temperature |
= | Velocity components in the x- and y-directions | |
= | Cartesian coordinates | |
= | Under-relaxation factor | |
= | Nominal diffusion coefficient | |
= | Density | |
= | General variable | |
= | Time step | |
= | Volume |
Subscripts | ||
e, w, … | = | east, west face of a control volume |
E, W,… | = | East, West neighbor of the main grid point |
nb | = | Neighbours of the P grid point |
P | = | Grid point P |
Superscripts | = | |
′ | = | Correction field |
0 | = | Values from previous time step or previous outer iteration |
* | = | Values from intermediate calculation |
** | = | Final values at present time step or present outer iteration |