Author: Caesar Wiratama, M.S
PT Tensor Karya Nusantara, Wiratama@pt-tensor.com
Abstract. This report documents an OpenFOAM validation of the classic Ahmed bluff body at 25° slant angle. A production baseline (CFD) was established at U∞ = 40 m/s, followed by a three-level grid-independence study (GIT) and a three-point Reynolds-number sensitivity analysis. Force coefficients Cd and Cl are compared with experimental targets (Cd = 0.299, Cl = 0.345 at Re 2.78×10⁶). The medium mesh (~0.70 M cells) yields Cd and Cl errors within about 1% and 2% of experiment, respectively. The fine mesh shows incomplete steady convergence of Cl. Reynolds-number sweeps on the medium mesh recover the expected mild decrease of Cd with Re.
