Fiber orientation in the frontal region of a center-gated disk: Experiments and simulation

Fiber orientation in the frontal region of a center-gated disk was measured for the first time and compared with orientation predictions using standard Folgar-Tucker and the reduced strain closure (RSC) model in coupled flow simulations. Fiber orientation was experimentally measured along three different heights representative of shell, transition and core layers, in order to understand the evolution of orientation along the radial direction in the frontal region. Orientation predictions of the Folgar-Tucker model and its two modified versions, the delayed Folgar-Tucker model and the RSC model were assessed against the measured experimental data. Orientation predictions with all three models showed a drop in orientation near the front, which was in qualitative agreement with the experimental data. Modified versions of the Folgar-Tucker model showed a relatively larger drop in orientation in the shell layer with predictions being relatively closer to experimental values. However, no significant slowdown was observed with the modified versions in the transition and core layers. With coupling of flow and orientation, the frontal flow region was slightly larger and orientation predictions showed only slight improvement. A significant improvement in the frontal region was obtained when a lower value of the interaction coefficient was used.