Abstract:This study numerically analyzes the film cooling performance of a novel serrated trench-hole structure under varying blowing ratios and streamwise pressure gradients to address cooling challenges in high-temperature turbine blades for heavy-duty gas turbines. The research focuses on the effects of favorable, zero, and adverse pressure gradients on film attachment, lateral cooling coverage, and wall temperature progression along the streamwise direction, using zero pressure gradient as a baseline. Results indicate that favorable pressure gradients significantly improve film attachment, extend cooling coverage, and effectively mitigate wall temperature rise by suppressing the vertical lift of the cooling jet. In contrast, adverse pressure gradients increase the cooling jet’s vertical penetration, causing a rapid temperature rise downstream. Cooling performance under zero pressure gradients remains intermediate, showing moderate effects. This study provides valuable insights and theoretical support for optimizing serrated trench-hole structures in turbine blade cooling applications.