Micro-grooving (Riblets) on the surface of an object is effective in reducing friction loss due to fluid flow and is applied in various fields such as aircraft. The effect of reducing friction loss in turbulent flow is particularly significant and is expected to be effective for turbine blades in which turbulence is enhanced by inverse pressure gradients. However, few studies have applied riblet to turbine blades, especially those that have investigated the riblet on loss reduction in turbine blades with peeling bubbles. In this study, turbine with and without the riblet were tested in a straight blade train test to investigate the effect of the riblet on loss reduction.
OHIKE et al. (2025) studied this question.