Thermal performance in latticework ducts with various endwall shapes for aero-craft turbine cooling

The latticework duct plays an important role in turbine blade cooling for aircraft engines. The present numerical research provided information about the thermal performance in latticework ducts with different endwall shapes. Each latticework duct analyzed in this study had a crossing angle of 90° and 11 sub channels on both the two sides of the endwall. A numerical investigation was conducted at five Reynolds numbers (11,000 to 55,000) and six endwall shapes. The local Nu number and flow structures were analyzed in detail. For a rectangular latticework duct, a jet region generated considerable Nusselt numbers, and the helical flow leaded to a uniform Nu number. Moreover, the turning and jet effects caused a high friction factor. The results also showed that an appropriate endwall shape could increase the thermal performance in a latticework duct. The different endwall shapes mainly altered the flow structure nearby the sidewall of the latticework, especially for the spiral flow. Moreover, the endwall shape also influenced the heat transfer and flow behavior. This phenomenon occurred because the different endwall shapes increased the turbulence of the cooling air to different extents.