Effects of grid resolution on axisymmetric stern flows computed with an incompressible viscous flow solver

Abstract

An incompressible Reynolds‐averaged Navier‐Stokes (RANS) computational procedure is presented. Numerical computations using a three‐dimensional computer code with multigrid capability are made on two axisymmetric bodies at a Reynolds number (about 10⁷) to investigate the effects of grid distribution and turbulence modeling on computed stern flows. Numerical‐experimental comparisons are presented for pressure and skin friction coefficients on the body, and axial velocity and turbulent shear stress profiles at two locations in the stern region. The root‐mean‐square (RMS) differences of the measured and computed flow variables are summarized. A grid‐independent numerical solution has been obtained from the present RANS computer code when the average value of y⁺ ₁ for the first grid center from the wall, has been less then 7, and the rate of covergence has been monitored to avoid the use of grid cells with excessively large aspect ratios. Two modifications of the Baldwin‐Lomax turbulence model have been shown to improve the predictions.

Key words:

• grid resolution
• axisymmetric body

Notes

Correspondence addressee