Numerical investigation of impingement heat transfer on smooth and roughened surfaces in a high-pressure turbine inner casing

Tong, Fujuan; Gou, Wenxuan; Zhao, Zhenan; Gao, Wenjing; Li, Honglin; Li, Lei

doi:10.1016/j.ijthermalsci.2019.106186

Cited by 32 publications

(3 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One can also observe that the induced flow asymmetries persist nearly over the whole nozzle length. These findings indicated a similar axial variation in velocity observed on both concave and flat surfaces [23,31,62]. Since it is outside the potential core region, the flow velocity impinging on the target surface has a reduced impact due to crossflow.…”

Section: Flow Featuressupporting

confidence: 63%

“…Most existing literature about roughened surfaces is on flat surfaces [18][19][20][21]. Likewise, structures such as ribs [22][23][24][25][26], fins [27][28][29][30][31], grooves [32][33][34][35], and dimples [36][37][38][39] can enhance the concave target surface's thermal performance. Additionally, the channel structure can be optimized for better heat transfer [40][41][42][43][44].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Heat and Flow Characteristics of Aerofoil-Shaped Fins on a Curved Target Surface in a Confined Channel for an Impinging Jet Array

Yalçınkaya,

Durmaz,

Tepe

et al. 2024

Energies

View full text Add to dashboard Cite

The main purpose of this investigation was to explore the heat transfer and flow characteristics of aero-foil-shaped fins combined with extended jet holes, specifically focusing on their feasibility in cooling turbine blades. In this study, a comprehensive investigation was carried out by applying impinging jet array cooling (IJAC) on a semi-circular curved surface, which was roughened using aerofoil-shaped fins. Numerical computations were conducted under three different Reynolds numbers (Re) ranging from 5000 to 25,000, while nozzle-to-target surface spacings (S/d) ranged from 0.5 to 8.0. Furthermore, an assessment was made of the impact of different fin arrangements, single-row (L1), double-row (L2), and triple-row (L3), on convective heat transfer. Detailed examinations were performed on area-averaged and local Nusselt (Nu) numbers, flow properties, and the thermal performance criterion (TPC) on finned and smooth target surfaces. The study’s results revealed that the use of aerofoil-shaped fins and the reduction in S/d, along with surface roughening, led to significant increases in the local and area-averaged Nu numbers compared to the conventional IJAC scheme. The most notable heat transfer enhancement was observed at S/d = 0.5 utilizing extended jets and the surface design incorporating aerofoil-shaped fins. Under these specific conditions, the maximum heat transfer enhancement reached 52.81%. Moreover, the investigation also demonstrated that the highest TPC on the finned surface was achieved when S/d = 2.0 for L2 at Re = 25,000, resulting in a TPC value of 1.12. Furthermore, reducing S/d and mounting aerofoil-shaped fins on the surface yielded a more uniform heat transfer distribution on the relevant surface than IJAC with a smooth surface, ensuring a relatively more uniform heat transfer distribution to minimize the risk of localized overheating.

show abstract

Section: Flow Featuressupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Heat and Flow Characteristics of Aerofoil-Shaped Fins on a Curved Target Surface in a Confined Channel for an Impinging Jet Array

Yalçınkaya,

Durmaz,

Tepe

et al. 2024

Energies

View full text Add to dashboard Cite

show abstract

“…The highest performance enhancement criterion of 1.25 was achieved at the nozzle-target plate spacing of 2.0. In a recently published research, Tong et al [60] performed a numerical investigation to study the heat transfer due to impingement on the inner casing of a high-pressure turbine. The numerical study was conducted for various target surface shapes, such as smooth, round, and square pin fin and cambered rib (see Figure 5).…”

Section: Pachpute and Premachandran [57]mentioning

confidence: 99%

Heat Transfer Augmentation through Different Jet Impingement Techniques: A State-of-the-Art Review

et al. 2021

View full text Add to dashboard Cite

Jet impingement is considered to be an effective technique to enhance the heat transfer rate, and it finds many applications in the scientific and industrial horizons. The objective of this paper is to summarize heat transfer enhancement through different jet impingement methods and provide a platform for identifying the scope for future work. This study reviews various experimental and numerical studies of jet impingement methods for thermal-hydraulic improvement of heat transfer surfaces. The jet impingement methods considered in the present work include shapes of the target surface, the jet/nozzle–target surface distance, extended jet holes, nanofluids, and the use of phase change materials (PCMs). The present work also includes both single-jet and multiple-jet impingement studies for different industrial applications.

show abstract

Numerical analysis of jet impingement cooling with elongated nozzle holes on a curved surface roughened with V-shaped ribs

Yalçınkaya,

Durmaz

2024

J Therm Anal Calorim

View full text Add to dashboard Cite

Numerical studies were performed in this study to analyze the effect of dimensionless elongated injection holes (G/d = 0.5, 2.0, 4.0, 8.0) on heat and flow characteristics on rib-roughened surfaces with an array of inclined impingement jets. Experimental and numerical data from existing literature were used to validate the numerical solution procedure’s heat transfer and flow characteristics in the semicircular test section. The turbulence equations were solved using the SST k-ω turbulence model by varying the Reynolds number from 5000 to 25,000. The curvature effect and staggered array pattern created an additional stagnation region between adjacent impinging jets on smooth surfaces, leading to a low heat transfer zone. Rectangular cross-sectional V-shaped ribs (VSR) were placed in regions where the stagnation point occurs to eliminate this disadvantage. The effect of different normalized rib heights (Hr/d = 0, 0.2, 0.3, 0.4) and rib angles (α = 30°, 45°, 60°, 90°) on the curved surface was also investigated to increase convective heat transfer performance and achieve more homogenous heat transfer distribution by relatively reducing the effect of thermal stresses. Flow properties, area-averaged and local Nusselt number variations on smooth and ribbed surfaces, and the thermal performance criterion (TPC) were investigated in detail. The results indicated an increase in overall heat transfer and a more evenly distributed measurement region compared to the conventional (unextended jet and smooth surface) jet impingement configuration. The most significant heat transfer enhancement from combining the elongated jets with VSR was 47.23% at Hr/d = 0.2 by reducing the G/d to 0.5. In addition, the highest TPC was determined as 1.07 on the proposed model with G/d = 2.0 and Hr/d = 0.2 at Re = 25,000.

show abstract

Numerical investigation of impingement heat transfer on smooth and roughened surfaces in a high-pressure turbine inner casing

Cited by 32 publications

References 32 publications

Heat and Flow Characteristics of Aerofoil-Shaped Fins on a Curved Target Surface in a Confined Channel for an Impinging Jet Array

Heat and Flow Characteristics of Aerofoil-Shaped Fins on a Curved Target Surface in a Confined Channel for an Impinging Jet Array

Heat Transfer Augmentation through Different Jet Impingement Techniques: A State-of-the-Art Review

Numerical analysis of jet impingement cooling with elongated nozzle holes on a curved surface roughened with V-shaped ribs

Contact Info

Product

Resources

About