Figure 13

(a) Foam resistance factor in visual and core cracks vs foam quality. (b) Foam resistance factors for visual and core cracks with different surface roughness. Foam quality 85%, surface roughness of core cracks increased from 1 to 3 and is included in Table 1. SDBS concentration was kept at 0.1 wt%, foam flow velocity ν in cracks was kept at 5 mm/s.