Effect of triangular-wing longitudinal vortex generator geometry on heat transfer and flow resistance in the impingement cooling

To enhance the impingement cooling performance of turbine blades, this study investigates the heat transfer mechanisms of triangular-wing longitudinal vortex generators (TLVGs) arranged on the target surface. TLVGs are evaluated under different heights (H), widths (W), and angles (α) within a Reynolds number range of 4000 to 10 000. The main conclusions are as follows: Increasing H leads to an increase in heat transfer on the target surface and flow resistance, with the optimal overall heat transfer performance observed at H = 0.5D, improving thermal performance factor (TPF) by 7.5%–9.0% compared to a smooth target surface. The effect of W on the heat transfer performance of the target surface is relatively small, and its increase slightly reduces flow resistance. For Reynolds numbers below 6000, the TLVG with W = 0.1D shows the best overall heat transfer performance; however, for Reynolds numbers above 6000, the TLVG with W = 0.4D exhibits the optimal performance. The TLVG at α = 60° significantly reduces flow losses in the impingement chamber, improving TPF by 6.8%–8.2% compared to a smooth target surface. The TLVG at α = 150° has the next highest TPF, improving by 5.3%–6.0%, but it enhances heat transfer capability more effectively than at α = 60°.