Surface temperature reduction by using dimples/protrusions in a realistic turbine blade trailing edge

Abstract

In this article, numerical simulations have been conducted on the heat transfer effect of dimple/protrusion layouts of a pin-finned wedge duct. Conjugate heat transfer calculations are further performed to investigate the cooling effect of modified schemes with dimples and protrusions added. Comparisons are carried out with a turbine second stage guide vane employed as the prototype. The dimple/protrusion-pin fin arrangement is set as the optimum one obtained above, and dimple depth/protrusion height varies from 0.2 to 0.3 times the structure diameter. It is found that the side-by-side arrangement and protrusion structure is more beneficial for the wedge duct endwall heat transfer. Comparison with the prototype blade shows that the addition of both dimples and protrusions are helpful in enhancing the trailing edge cooling effect. The cooling effect is increased with an increase in dimple depth/protrusion height. The results also show that the modified blade with protrusions attached at 0.3 height saves 0.48 g/s cooling mass flow and reaches the most positive performance with a 17 K, 14 K average temperature reduction, 0.022, 0.018 cooling effect increasing for pressure, suction side, respectively.

Effects of Channel Outlet Configuration and Dimple/Protrusion Arrangement on the Blade Trailing Edge Cooling Performance

“…It can be found that the Nusselt number of the k-ω model and the SST k-ω model exhibits the similar variation as the experimental data, and the SST k-ω model presents a smaller relative deviation, within 8.2%. Moreover, literatures [14,22,25] also demonstrate that the SST k-ω model gives high simulation accuracy in the fluid flow and heat transfer of blade trailing edge. Accordingly, the SST k-ω model is applied in this paper.…”

“…Taslim et al [24] experimentally and numerically investigated the impingement cooling performance in the trailing edge channels with ribs, and analyzed the effects of jet angle and Re. Luo et al [25] constructed cooling channels with fin-dimple/protrusion composite structures, and concluded that, after numerical investigations, the increase in the dimple/protrusion depth was helpful to improve the heat transfer enhancement. Furthermore, Ye et al [26] numerically investigated the cooling performance of perforated blockages with inclined holes, and found that the cooling technology greatly improved heat transfer while producing high flow resistance.…”

A high temperature turbine blade heat transfer multilevel design platform

“…Many works investigated the effect of the shape, height to diameter, and arrangement on the heat transfer [8][9][10][11]. In addition to the existing methods, dimples [12][13][14], impingement [15][16][17], and porous materials [18,19] have been gradually studied.…”

Heat transfer characteristics of a dimpled/protrusioned pin fin wedge duct with different converging angles for turbine blades

“…The results showed that the combination of rib and protrusion techniques in a rectangular channel had the potential to provide heat transfer enhancement with low pressure drop penalty. Luo et al [32,33] utilized a numerical method to investigate the flow structure and heat transfer characteristics of a channel/duct with dimples/protrusions. According to their findings, channels with converging angle showed better heat transfer augmentation but was also accompanied with a larger pressure loss.…”