Numerical investigation on the flow character and film cooling performance of novel merged holes structure

Zhou, Jifu; Wang, Xinjun; Li, Jun; Hou, Weitao

doi:10.1007/s00231-019-02684-0

Cited by 5 publications

(2 citation statements)

References 22 publications

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“…The above comparison supports the findings of a recent study (Madrane et al, 2020) that the V-shape cooling holes (which are, to some extent, similar to the third modified hole exit shape) yield better cooling effect than the round hole. The trailing-edge of the second modified hole exit shape (the best performing geometry) resembles that of the dumbbell-shaped (Kim et al, 2012) and the merged cylinders (Zhou et al, 2019) cooling holes; however, the second modified nozzle yields a narrower streamwise hole exit space. Instead of keeping a constant cross section along the coolant nozzle (the merged cylinders) or shaping the coolant hole only near the exit (the dumbbell-shaped hole), the current study added more flexibility by enabling irregular geometry changes across the entire length of the coolant nozzle to obtain the maximum benefit from the adjoint solver.…”

Section: Identifying the Optimum Geometrymentioning

confidence: 99%

“…The dumbbell-shaped hole starts out cylindrical but as it nears the discharge, it looks like two cylinders that merged. The concept of merged cylinders along the entire length of the coolant nozzle was later investigated (Zhou et al, 2019) for different merge ratios; the best cooling coverage and effectiveness were achieved with the largest merge ratio.…”

Section: Introductionmentioning

confidence: 99%

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Numerical optimization study for the geometry of film cooling nozzle

Alshehaby

El-Gabry

2022

J. Glob. Power Propuls. Soc.

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Film cooling is one of the essential approaches developed to protect gas turbine blades and vanes from high temperature gases. It does so by covering the surface with a film of coolant air. Experimental and numerical studies have identified the parameters affecting film cooling aerodynamic and thermal behaviours; one of the most important is the coolant nozzle geometry. In this study, the nozzle geometry is optimized to enhance film effectiveness and heat transfer while keeping the inlet area and pitch-to-hole-width ratio fixed. A Reynolds-Averaged Navier Stokes (RANS) model, developed and validated against experimental data, served as the baseline for further optimization. The model was used to design a “racetrack slot” which is rectangular slot with semi-circular lateral edges. The aspect ratio of the slot was varied and an aspect ratio of seven was found to have the best cooling performance. As such, it served as the starting point for further, irregular, shape optimization of the coolant nozzle utilizing the ANSYS Fluent Adjoint solver. This solver allows mesh morphing within specified constraints and yielded a highly irregular coolant hole which taps into the potential of using additive manufacturing to produce cooled parts. The irregular shape optimization increased adiabatic film effectiveness over the test surface from 0.24 (for optimum racetrack coolant hole) to 0.34 (for optimum, irregular, coolant nozzle geometry). The enhancement is remarkable, especially when compared to 0.1; the value for the round coolant hole under the same conditions.

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Section: Identifying the Optimum Geometrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%