Numerical Study on Liquid-Film Cooling at High Pressure

This paper presents a numerical study to investigate the feasibility of transporting mist through the internal cooling channel in high-pressure turbine vanes for film cooling over the vane’s surface. The idea of using mist film cooling to enhance conventional air cooling has been proven to be a feasible technique in the laboratory conditions and by computational simulations. However, there is a challenge to this technique to prove that the water mist can survive in the very hot environment inside the gas turbine casings and internal air passages and be delivered to the film injection holes. Both a zero-dimensional mist evaporation analytical model and 3-D computational fluid dynamic (CFD) scheme are employed for analysis. In the CFD simulation, the Lagrangian /Eulerian method is used along with the discrete phase model (DPM) to track the evaporation process of water droplets. The high-pressure water mist is injected into the stream of cooling air extracted from the compressor through the outer gas turbine casing near the vane before it reaches the vane internal cooling cavity. Using the mist equivalent of 10% of the cooling air mass flow rate, the results show that, when the liquid droplets are atomized to 30 μm in diameter initially, the droplets can survive inside the internal cooling passages and be delivered to the film cooling injection hole location with droplets of 20 μm in diameter; and alternatively, an initially 20 μm droplet can be delivered at 12μm in diameter, which is sufficiently large for completing the required external film cooling task.

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Numerical study of liquid film cooling in a turbulent gas stream

International Journal of Heat and Mass Transfer ◽

10.1016/0017-9310(93)90138-v ◽

1993 ◽

Vol 36 (16) ◽

pp. 3877-3885 ◽

Cited By ~ 23

Author(s):

Wei-Mon Yan ◽

Soong Chyi-Yeou

Keyword(s):

Liquid Film ◽

Film Cooling ◽

Numerical Study

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Experimental and numerical study of supersonic film cooling

AIAA Journal ◽

10.2514/3.13913 ◽

1998 ◽

Vol 36 ◽

pp. 915-923 ◽

Cited By ~ 1

Author(s):

B. Aupoix ◽

A. Mignosi ◽

S. Viala ◽

F. Bouvier ◽

R. Gaillard

Keyword(s):

Film Cooling ◽

Numerical Study

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Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽

10.3390/pr9050841 ◽

2021 ◽

Vol 9 (5) ◽

pp. 841

Author(s):

Yuzhen Jin ◽

Huang Zhou ◽

Linhang Zhu ◽

Zeqing Li

Keyword(s):

Liquid Film ◽

Weber Number ◽

Stokes Equations ◽

Numerical Study ◽

Three Dimensional ◽

Navier Stokes ◽

Single Droplet ◽

Navier Stokes Equations ◽

Volume Method ◽

The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

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Numerical Study of the Effect of Blowing Angle on Cooling Effectiveness of an Effusion Cooling

Volume 3: Turbo Expo 2004 ◽

10.1115/gt2004-54043 ◽

2004 ◽

Cited By ~ 3

Author(s):

Yaping Hu ◽

Honghu Ji

Keyword(s):

Film Cooling ◽

Numerical Study ◽

Coolant Flow ◽

Cooling Effectiveness ◽

Absolute Value ◽

Blowing Ratio ◽

Conventional Film

The paper numerically investigates the influences of the blowing angle α of coolant flow on the cooling effectiveness of effusion cooling of a plate. Nine cases were studied which cover three blowing angles of α = 30°, 60°, 90° and for each angle three blowing ratios of M = 0.5, 1.0, 2.0 are calculated, respectively. The results show that with the increase of α the cooling effectiveness reduces for all the calculated cases. For the cases of α = 30° and 60° the distribution of cooling effectiveness η along the whole plate are very similar for any given blowing ratio, especially when M = 1.0 and 2.0. Whereas for the cases of α = 90°, the distributions of cooling effectiveness are quite different from other two blowing angles for a given blowing ratio, especially for M = 1.0 and in the trailing region of the plate. Although the cooling effectiveness of the cases with α = 90° for any given blowing ratio is the worst one among the three angles (α = 30°, 60°, and 90°) stated, its absolute value is still quite high comparing to the conventional film cooling.

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3D numerical study of the liquid film distribution on the surface of a horizontal-tube falling-film evaporator

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2018.04.020 ◽

2018 ◽

Vol 124 ◽

pp. 943-952 ◽

Cited By ~ 28

Author(s):

Qinggang Qiu ◽

Xiaocui Zhang ◽

Shenglin Quan ◽

Xiaojing Zhu ◽

Shengqiang Shen

Keyword(s):

Liquid Film ◽

Numerical Study ◽

Horizontal Tube ◽

Falling Film ◽

Film Evaporator ◽

Film Distribution

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Experimental and Numerical Study on the Effects of the Relative Position of Film Hole and Orientation Ribs on the Film Cooling With Ribbed Cross-Flow Coolant Channel

Volume 7B: Heat Transfer ◽

10.1115/gt2020-14389 ◽

2020 ◽

Author(s):

Bingran Li ◽

Cunliang Liu ◽

Lin Ye ◽

Huiren Zhu ◽

Fan Zhang

Keyword(s):

Heat Transfer ◽

Relative Position ◽

Film Cooling ◽

Numerical Study ◽

Cross Flow ◽

Internal Cooling ◽

Transfer Coefficients ◽

Cooling Performance ◽

Heat Transfer Coefficients ◽

Numerical Studies

Abstract To investigate the application of ribbed cross-flow coolant channels with film hole effusion and the effects of the internal cooling configuration on film cooling, experimental and numerical studies are conducted on the effect of the relative position of the film holes and different orientation ribs on the film cooling performance. Three cases of the relative position of the film holes and different orientation ribs (post-rib, centered, and pre-rib) in two ribbed cross-flow channels (135° and 45° orientation ribs) are investigated. The film cooling performances are measured under three blowing ratios by the transient liquid crystal measurement technique. A RANS simulation with the realizable k-ε turbulence model and enhanced wall treatment is performed. The results show that the cooling effectiveness and the downstream heat transfer coefficient for the 135° rib are basically the same in the three position cases, and the differences between the local effectiveness average values for the three are no more than 0.04. The differences between the heat transfer coefficients are no more than 0.1. The “pre-rib” and “centered” cases are studied for the 45° rib, and the position of the structures has little effect on the film cooling performance. In the different position cases, the outlet velocity distribution of the film holes, the jet pattern and the discharge coefficient are consistent with the variation in the cross flow. The related research previously published by the authors showed that the inclination of the ribs with respect to the holes affects the film cooling performance. This study reveals that the relative positions of the ribs and holes have little effect on the film cooling performance. This paper expands and improves the study of the effect of the internal cooling configuration on film cooling and makes a significant contribution to the design and industrial application of the internal cooling channel of a turbine blade.

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