Additive manufacturing allows the fabrication of relatively complex cooling structures, such as triply periodic minimal surface (TPMS), which offers high heat transfer per unit volume. This study shows the turbulent flow heat transfer and thermal stress of the Diamond-TPMS topology in the gas turbine blade trailing edge channel. The thermal-fluid-solid analysis of the Diamond-TPMS structure, made of directionally solidified GTD111, at the nearly realistic gas turbine condition is executed, and the results are compared with the conventional pin fin array at the Reynolds number of 30,000. Compared to the baseline pin fin structure, the Diamond-TPMS model distributes flow characteristics more uniformly throughout the channel. The overall heat transfer enhancement, friction factor ratio, and thermal performance are increased by 145.3%, 200.9%, and 32.5%, respectively. The temperature, displacement, and thermal stress in the Diamond-TPMS model are also distributed more evenly. The average temperature on the external surface in the Diamond-TPMS model is lower than the baseline pin fin array by 19.9%. The Diamond-TPMS network in the wedge-shaped cooling channel helps reduce the volume displacement due to the material thermal expansion by 29.3%. Moreover, the volume-averaged von Mises stress in the Diamond-TPMS structure is decreased by 28.8%.

This work designs a Diamond-type triply periodic minimal surface (TPMS) structure that exhibits excellent thermomechanical properties in a gas turbine blade trailing edge to enhance thermal performance and improve heat transfer uniformity. Since the velocity and temperature distributions are altered in the rotating trailing edge channel, the flow and heat transfer characteristics of the baseline pin fin and Diamond TPMS models are numerically investigated at the Reynolds number of 10,000 and the rotation numbers of 0.0–0.28. Compared to the baseline model, the Diamond TPMS network significantly decreases recirculation flow at the inner wall, improving heat transfer, especially at the tip and outlet regions. Although the Diamond TPMS model incurs substantial pressure losses from 191% to 234%, it yields significantly higher overall heat transfer than the pin fins by 179%. Consequently, the thermal performance increased by 93.4%. The flow fluctuations due to the rotating effects are minor in the Diamond TPMS architecture, considerably reducing the differences in heat transfer between the leading and trailing walls. The differences in the wetted-area averaged Nusselt number of the baseline and Diamond TPMS models within the studied rotation numbers are 8.5–14.4% and about 8.5%, respectively. Moreover, the Diamond TPMS structure reduces the differences in heat transfer between the root and tip regions at the outlet by up to 80% compared to the pin fins. This improvement helps protect the trailing edge from thermal failure, thereby potentially prolonging the gas turbine blade's lifetime.

This study introduces the Gyroid structure, a type of triply periodic minimal surface (TPMS), for enhanced effusion cooling performance. Conjugate heat transfer simulations are used to compare the flow behavior, pressure loss, and overall cooling effectiveness of single- and double-wall Gyroid configurations against a baseline film hole model at blowing ratios of 0.5–2.0. Results show that the Gyroid design eliminates jet lift-off and counter-rotating vortex pairs, ensuring full coolant coverage and a thicker coolant layer than the baseline. The double-wall configuration further improves cooling with jet impingement, yielding higher average Nusselt numbers than the single-wall design. At equal pressure loss, the impingement/Gyroid model outperforms the baseline by 102.7% in cooling effectiveness. To assess manufacturability, a high-resolution CT scan is used to validate a laser powder bed fusion-printed Gyroid sample at gas turbine blade scale, confirming feasibility for industrial application. These findings highlight the superior thermal performance and manufacturability of the 3D-printed Gyroid structure, offering a promising cooling solution for next-generation turbine blades.

Heat transfer and pressure loss characteristics of a novel Vortex rib in a cooling channel have been studied both experimentally and numerically under the Reynolds numbers from 10,000 to 80,000 and rotation numbers from 0 to 0.385. The Vortex rib is proposed by combining W-rib and W-patterned oblong dimple. Compared with the W-rib, the Vortex rib enhances heat transfer by up to 11.4% (Re = 10,000 and Ro = 0.31) while reducing the pressure loss by up to 18.7% (Re = 32,000 and Ro = 0) under non-rotating and rotating conditions. Compared to the W-patterned oblong dimple, the heat transfer of the Vortex rib increases by up to 47.9%. The heat transfer dead zones are significantly improved by near-wall vortex induced by Vortex rib. The Vortex rib can appreciably reduce the turbulent mixing intensity in the mainstream of the cooling fluid but keep the near-wall high turbulent mixing intensity, guaranteeing the turbulent heat transport capacity. Thus, the heat transfer can be improved while maintaining the pressure loss in the channel.

This research numerically investigates the cooling performance of Diamond-type triply periodic minimal surface (TPMS) networks as a gas turbine effusion cooling layer, augmented with various jet impingement configurations. The study analyzes the internal and external flow characteristics, pressure loss, and overall cooling effectiveness using conjugate heat transfer simulations. The Diamond design is compared to conventional film cooling and micro-hole models within a blowing ratio range of 0.5 to 2.0. The jet hole diameter and jet-to-plate distance are varied to identify an optimal double-wall cooling configuration. The results reveal that the Diamond hole mitigates the strong discharge of coolant, resulting in a more adherent cooling film, which provides excellent surface coverage. While jet impingement enhances internal heat transfer, its contribution to cooling effectiveness is minor compared to the benefit of film coverage. At an equivalent total pressure loss coefficient, the Diamond with impinging jets demonstrates 101% higher cooling effectiveness than the film hole. The thermal-mechanical analysis indicates that the Diamond model exhibits a more uniform distribution of thermal stress and displacement. The average stress is reduced by 44.7% compared to the film hole. This work confirms the TPMS-based effusion as an advanced cooling solution for next-generation gas turbines.

Experiments and numerical simulations are conducted to investigate the flow and heat transfer characteristics of the guiding pin-fin array in a rotating wedge-shaped channel that represents the internal cooling passage features for turbine blade trailing edges. The rotating experiments cover Reynolds number ranges from 10,000 to 80,000 and rotation number ranges from 0 to 0.46. The results demonstrate that, with a proper arrangement, the guiding pin-fin array can significantly reduce the endwall temperature and pressure loss in the wedge-shaped channel. However, it was observed that at the midspan of the guiding pin-fin array channel, heat transfer was relatively low, forming a high-temperature region. To enhance channel heat transfer uniformity, 2 mm clearances were introduced to the guiding pin-fins at the channel root region, 2 mm from the trailing endwall. The numerical results show that this structural modification effectively improved the endwall heat transfer intensity at the midspan of the wedge-shaped channel, particularly on the leading surface. In cases with Reynolds number (Re) equal to 50,000 and rotation number (Ro) equal to 0.075, the leading and trailing endwall Nusselt numbers of the detached guiding pin-fin array were 6.5% and 4.8% higher than those of the guiding pin-fin array. The secondary flow and transverse vortex induced by the detached pin-fins reduced the main stream velocity, thereby inhibiting the Coriolis force effect and diminishing the endwall heat transfer discrepancy. Further comparisons at Re = 50,000 and Ro = 0.075 and 0.15 revealed that the leading and trailing endwall heat transfer discrepancy coefficient (δ) of the detached guiding pin-fin array was 61.8% and 42.2% lower than that of the circular pin-fin array, respectively. In high-temperature cases with solid domain, which are closer to the real turbine blade operating condition, the detached guiding pin-fin array also can provide superior cooling performance. In the wedge-shaped channel with detached guiding pin-fin, the maximum and average temperature values of the solid domain are about 10% lower than that of the channel with circular pin-fin, at both rotating and stationary conditions.