Parametric investigation of V-shaped rib designs for jet impingement in gas turbine blade leading-edge cooling channel

Jet array impingement cooling is widely used for gas turbine blades due to high heat transfer potential. However, crossflow effects and the pressure drop can limit cooling performance, particularly with roughened enhanced cooling channels. Previous studies have mainly considered isolated geometric parameters, while rib length and interaction influence of multiple parameters remained less understood. In the present study, the heat and fluid flow of V-shaped ribs in a leading-edge cooling channel was investigated numerically. Steady Reynolds-averaged Navier-Stokes simulations were performed under a constant Reynolds number of 30,000 and a jet pitch of 5 D j . Rib angle ( θ = 30–90°), rib height ( h r = 0.25 D j –0.75 D j ), rib length ( l r = 2 D j –4 D j ), and rib–jet spacing ( s rj = 0–3.75 D j ) were considered. Nusselt number, total heat transfer rate, pressure drop, and PEC were used to assess the effectiveness of ribs. Results demonstrate that V-shaped ribs intensify turbulence production and secondary-flows, and reduce the negative effect of downstream crossflow, accordingly, produce higher Nusselt numbers for majority of configurations. According to findings, θ range of 45–60° is the most beneficial for individual thermal augmentation. Considering the pressure drop, θ = 30° provides the best PEC in Re = 30,000. Also, l r and h r directly affect all metrics at angles less than 60°, while at larger angles the influence merely on PEC is reversed. As for s rj , overall, all objectives slightly decrease. Nusselt number and heat transfer rate were maximally enhanced by 25% and 55% for the case of θ = 45°, h r = 0.75 D j , l r = 4 D j , and s rj = 1.25 D j . Additionally, best PEC = 1.35 was obtained for θ = 30°, h r = 0.75 D j , l r = 4 D j , and s rj = 3.75 D j .