Flow and heat transfer characteristics of double-wall cooling with multi-row short film cooling hole arrangements

2021 ◽  
Vol 165 ◽  
pp. 106878
Author(s):  
Yuyang Liu ◽  
Yu Rao ◽  
Li Yang ◽  
Yamin Xu ◽  
Alexandros Terzis
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Short Film ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Cooling Hole ◽  
Double Wall

Numerical Study on Influencing Factors of Film Cooling on Turbine Blade Leading Edge Under Rotating State

2018 ◽  
Author(s):  
Yiwen Ma ◽  
Haiwang Li ◽  
Meisong Yang ◽  
Min Wu ◽  
Huimin Zhou
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Turbine Blade ◽  
Rotation Number ◽  
Film Cooling ◽  
Leading Edge ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Blade Leading Edge

Engine turbine blades operate at a high speed of rotation and are subjected to high temperature and pressure prevailing gas from the combustion chamber, making the working condition very harsh. In particular, the leading edge of the blade, which is directly subjected to high-temperature gas impacts, is the hottest part of the turbine. Therefore, it is of great importance to improve the protection of the blade leading edge and enhance the understanding of this part of the flow field and temperature field. This paper will focus on the phenomenon of wake deflection and study the film cooling characteristics of the turbine blade under rotating condition. The characteristics of pressure surface and suction surface of the blade are verified by numerical simulation. The contents cover the influence of the film hole diameter, pitch, blowing ratio, rotation number and the development process, the film cooling efficiency on the outflow of coolant film. The result shows that Coriolis force, centrifugal force and secondary flow induced by rotation will change the mainstream flow along the blade, which will lead to changes of pattern concerning the development of the film on the blade surface. In the process of wake development, deflection occurs in different directions at different positions, and the greater the rotation number is, the more obvious the degree of deflection will be. Studying the model with film holes on the leading edge of the blade, these phenomena can be observed along the downstream on the pressure and suction surfaces. Also, models with film holes independently set on the pressure and suction surfaces can be used as proof of these features. At the same time, this paper studies the flow and heat transfer characteristics of the leading-edge gas film under rotating condition and focuses on the influence of rotation on the outflow and the development processes of the wake. The gas film cooling models in rotating state of different film hole diameters and film hole radial spacing will also be compared to further understand the flow and heat transfer characteristics of film cooling on the leading edge of the blade.

Local Internal Impingement Heat Transfer Near a 90 Deg Row of Film Cooling Holes: Part 2 — Effect of Jet Row Position

2006 ◽  
Author(s):  
Lei Xu ◽  
Haiping Chang ◽  
Guoqiang Chang
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Flux Ratio ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Heat Transfer Characteristics ◽  
Target Plate ◽  
Transfer Characteristics ◽  
Cooling Hole ◽  
Film Cooling Holes

Investigation of local heat transfer characteristics near a row of film cooling holes in the inner side of a simulated turbine blade midchord region with impingement has been carried out experimentally. The research about heat transfer characteristics is focused on three diameter of film cooling hole area located upstream and downstream a row of film cooling holes, which angle is at a 90 degrees. The internal impingement air is provided by a single line of equally spaced jets. The film cooling air extracts through a line of holes on the impinging target plate. The projection of the jets on the target plate is always on the center line between two film holes. The spacing of the jet holes is twice that of the film cooling holes. The effect of the streamwise arrangement of the impingement nozzles relative to the position of the film cooling holes and impinging distance on the heat transfer characteristics have been mainly investigated. The experiment is conducted under the flow condition of Reynolds number 10000∼30000, crossflow-to-jet mass flux ratio based on each channel/jet hole section area 0.1 and film outflow-to-crossflow mass flux ratio based on film cooling hole/channel section 12∼20. In the range of experimental parameter, the experimental results indicate that there is optimal ratio of the impinging distance to film hole diameter, on which the heat transfer characteristics is best. Similarly for the area upstream film cooling hole, there is the optimal ratio of distance of the impingement nozzles relative to the position of the film cooling holes to film hole diameter. As impinging holes are away from film cooling holes in the streamwise direction of crossflow, the effect of impingement on local heat transfer near film cooling holes is weakened, but film cooling extraction effect stand out. The place closer to the hole will have stronger heat transfer whether upstream the film cooling holes or downstream the holes. Based on this, the effects of position of the jets relative to the film cooling holes on the heat transfer characteristics have been obtained qualitatively and quantitatively. It can be the important reference for accurately designing gas turbine blade.

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