Experimental investigation of wall thickness and hole shape variation effects on full-coverage film cooling performance for a gas turbine vane

Li, Weihong; Li, Xueying; Ren, Jing; Jiang, Hongde

doi:10.1016/j.applthermaleng.2018.08.068

Cited by 30 publications

(4 citation statements)

References 45 publications

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“…The choice of the hole exit shape is a usual problem in the study of film cooling. 15,16 In this study, we refer to the optimization method of hole shape in the film cooling and apply the method to the study of the endwall VGJs. The effect of the hole exit shape on the aerodynamic performance of the compressor cascade is discussed.…”

Section: Introductionmentioning

confidence: 99%

Optimization of the hole exit shape of the vortex generator jets in a compressor cascade

Chen

2021

Proceedings of the Institution of Mechanical Engineers, Part G:

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Vortex generator jets usually use a circular hole. The hole exit shape is also an important parameter, so the change of the shape will have a significant influence on the control effect of the compressor. In this article, the optimization design of the hole exit shape is studied in order to find the optimal geometry. The 2D hole exit shape is represented with a binary coded and initialized with the B-spline. The surrogate-based optimizer consists of a parametric design code, a computational fluid dynamics solver, a Kriging model, an infill sample criterion, and a genetic algorithm. First, the design of the symmetric hole is studied in a low ratio of the jet to inlet mass flow. The circumferential length of the designed hole is fixed. Second, both the symmetric hole and the asymmetric hole are studied. And the area of the hole exit shape is fixed. The results show that the optimal hole shape can enhance the strength of the jet vortex and reduce the total pressure loss of the compressor cascade. A better control effect can also be obtained in a high jet mass flow.

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Section: Introductionmentioning

confidence: 99%

Optimization of the hole exit shape of the vortex generator jets in a compressor cascade

Chen

2021

Proceedings of the Institution of Mechanical Engineers, Part G:

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“…They found that the correlations developed for flat plate configurations overestimated the film cooling effectiveness at the pressure side and the last cooling hole row of the suction side. Li et al [8] measured the film cooling effectiveness on a full-coverage film cooled turbine vane with three hole configurations: cylindrical hole, compound angle hole, and fan-shaped hole.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Hole Arrangement and Density Ratio on the Heat Transfer Coefficient Augmentation of Fan-Shaped Film Cooling Holes

et al. 2021

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An experimental study was performed to investigate the effects of the arrangement of fan-shaped film cooling holes and density ratio (DR) on heat transfer coefficient augmentation. Both single- and multi-row fan-shaped film cooling holes were considered. For the multi-row fan-shaped holes, the heat transfer coefficient was measured at DRs of 1 and 2, and both staggered and inline arrangements of holes were considered. For the single-row fan-shaped holes, DR = 1.0, 1.5, 2.0, and 2.5 and M = 1.0 and 2.0 conditions were tested. The mainstream velocity was 20 m/s, and the turbulence intensity and boundary layer thickness were 3.6% and 6 mm, respectively. The heat transfer coefficient was measured using the one-dimensional transient infrared thermography method. The results show that an increased heat transfer coefficient augmentation is observed between film cooling holes for the case with a smaller hole pitch and higher blowing ratio. For the given fan-shaped hole parameters, the effects of the row-to-row distance and hole arrangement are not significant. In addition, as the velocity difference between the mainstream and coolant increases, the heat transfer coefficient ratio increases.

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“…The ongoing desire to achieve higher thermal efficiency while lower cooling air consumption promotes combined cooling concepts to be proposed. 1,2 Near turbine blade trailing edge (TE) region, TE slots coupling with upstream discrete film-holes and internal pedestals (as illustrated in Figure 1(a)) have been widely designed to effectively respond the challenges of severe local high temperature level. [3][4][5] Hence, the actual coolant coverage performance at cutback surface is determined by the interaction of hot mainstream, TE slot outflow and upstream pressure side (PS) film-ejection.…”

Section: Introductionmentioning

confidence: 99%

Exit-shape effect of film holes at pressure side on trailing edge cutback film cooling characteristics

Wang

Song

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part A:

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Pressure side (PS) cutback structure has been widely employed in modern turbine blade trailing edge (TE) cooling design. However, hot gas flows around lip of TE slot to generate an impingement to cutback, resulting in a rapid decay of film cooling effectiveness and hence thermal damage of entire TE. Proper angled-ejections upstream of TE can suppress the downstream effectiveness-decay. Therefore, in present work, five types of film-holes were designed to discuss the effect of exit-shape of film-hole on TE film cooling characteristics, inlet boundary layer profile, fluid-interactions, discharge behaviors and total pressure losses. The studied models included cylindrical-hole, common and laidback fan-shaped film-holes, and converging slot-holes with two different exit-to-inlet area ratios ( ARs). The solo cutback cooling was chosen as a reference. Thermal tests were conducted in a hot wind tunnel featuring a simplified TE test section by infrared thermal technique. Engine-similar mainstream-to-coolant temperature ratio of 2.0 was controlled. Comparisons of experimental results revealed that the converging slot-holes can obtain the highest film cooling effectiveness at TE region and overall cooling effectiveness at PS film-plate, but the slightest increase of total pressure losses. Flow measurements using Particle Image Velocimetry technique indicated the converging slot-holes can modify the inlet boundary layer profile, suppress effectively the impingement of mainstream and change the flow separation features at cutback. In addition, applying shaped-holes can effectively suppress the flow ingestion under low coolant amounts. However, relative to the exit-shape effect, the coolant amount plays a more important role on the aerodynamic and thermal characteristics of TE cooling.

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Experimental investigation of wall thickness and hole shape variation effects on full-coverage film cooling performance for a gas turbine vane

Cited by 30 publications

References 45 publications

Optimization of the hole exit shape of the vortex generator jets in a compressor cascade

Optimization of the hole exit shape of the vortex generator jets in a compressor cascade

The Effects of Hole Arrangement and Density Ratio on the Heat Transfer Coefficient Augmentation of Fan-Shaped Film Cooling Holes

Exit-shape effect of film holes at pressure side on trailing edge cutback film cooling characteristics

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