INVESTIGATION OF EFFUSION/FILM COOLING EFFICIENCY FOR SHARP CONE HEAT FLUX CONTROL AT HIGH SUPERSONIC SPEEDS

2014 ◽  
Vol 45 (1) ◽  
pp. 61-87
Author(s):  
Pavel Vladimirovich Chuvakhov
Keyword(s):  
Heat Flux ◽  
Film Cooling ◽  
Cooling Efficiency ◽  
Flux Control ◽  
Sharp Cone ◽  
Film Cooling Efficiency

scholarly journals Comparison of turbine blade film cooling efficiency between PSP and TLC techniques in a stationary wind tunnel

AIP Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 015333
Author(s):  
Xiaojian He ◽  
Haiwang Li ◽  
Guoqin Zhao ◽  
Ruquan You
Keyword(s):  
Wind Tunnel ◽  
Turbine Blade ◽  
Film Cooling ◽  
Cooling Efficiency ◽  
Film Cooling Efficiency

Effects of flow turbulence on film cooling efficiency

1995 ◽  
Vol 38 (11) ◽  
pp. 2117-2125 ◽  
Author(s):  
V.P. Lebedev ◽  
V.V. Lemanov ◽  
S.Ya. Misyura ◽  
V.I. Terekhov
Keyword(s):  
Film Cooling ◽  
Cooling Efficiency ◽  
Flow Turbulence ◽  
Film Cooling Efficiency

Use of Photo-Stimulated Luminescence Piezospectroscopy and Lifing Models to Evidence Film Cooling Effect on EB-PVD Ceramic Thermal Barriers of Ex-Service Blades

2010 ◽  
Author(s):  
Claudia Rinaldi ◽  
Letizia de Maria ◽  
Ada del Corno
Keyword(s):  
Film Cooling ◽  
Quantitative Relationship ◽  
Thermally Grown Oxide ◽  
Thermal Barrier ◽  
Cooling Efficiency ◽  
Thermal Barriers ◽  
Life Model ◽  
Non Destructive ◽  
Film Cooling Efficiency ◽  
Life Fraction

The very scattered life times of thermal barrier coatings used on the first stage rotating blades of GTs used in power generation plants encourage the development of reliable non destructive techniques to reliably detect degradation before spalling. Among the optical non contact techniques Photo stimulated Luminescence PiezoSpectroscopy (PLPS) is promising as it lets to measure the residual compressive stress values of the thermally grown oxide (σTGO) at the interface between the BC and the ceramic top coat of EB-PVD thermal barriers. This paper underlines the potentiality of the photoluminescence piezospectroscopy as a diagnostic tool to assess the actual local film cooling efficiency on ex service blades with EB-PD TBCs. TGO stress values measured by PLPS (well related to the local degradation level of the interface, as observed on metallographic sections) result to be correlated with holes positions at all the different height of the blade examined. Moreover the reliability of the NDT evaluation is shown to increase significantly with an automatic PLPS instrumentation able to map σTGO in the regions of interest. The recorded large number of σTGO values suitably elaborated give a statistically significant evaluation of the degradation level reached by the TBC/BC interface, before spallation. A quantitative relationship between spent life fraction and σTGO formulated in the literature is here extended to ex-serviced blades to quantify the NDT result in terms of spent life fraction. These results are discussed in the light of T and spent life fraction estimates made with a simplified life model of TBC coatings.

Large eddy simulation of saw tooth plasma actuator for improving film cooling efficiency

2017 ◽  
Vol 231 (5) ◽  
pp. 357-370 ◽  
Author(s):  
Guozhan Li ◽  
Jianyang Yu ◽  
Fu Chen ◽  
Huaping Liu ◽  
Yanping Song ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Flat Plate ◽  
Film Cooling ◽  
Three Dimensional ◽  
Plasma Actuator ◽  
Cooling Efficiency ◽  
Flow Topology ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Film Cooling Efficiency

This paper presents results on a saw tooth plasma actuator for the inducement of flow topology and the improvement of flat plate film cooling efficiency. A phenomenological plasma model is constructed to generate the three-dimensional plasma force vectors of the saw tooth plasma actuator. The dynamics of airflow induced by the saw tooth plasma actuator on a flat plate in quiescent air are numerically investigated. The results show that the saw tooth plasma actuator pushes the fluids in all three directions and induces a three-dimensional jet flow with counter rotating streamwise oriented vortices that propagate downstream. The flow field characteristics of both cylindrical hole with and without the saw tooth plasma actuator are studied by large eddy simulation, and a comparison is made. The saw tooth plasma actuator improves the cold jet adherent performance and promotes the spanwise spreading rate of the coolant. Meanwhile, the streamwise vortices induced by the saw tooth plasma actuator suppress the development of counter-rotating vortex pair, thus delaying the diffusion of coolant in the crossflow. Accordingly, the centerline cooling efficiency and the spanwise-averaged cooling efficiency are improved by 36% and 144% at x/ d = 15, compared with the baseline case without the saw tooth plasma actuator.

Full Three-Dimensional Optimization Platform of Turbine Blades Considering the Film Cooling

2013 ◽  
Author(s):  
Shaopeng Lu ◽  
Zhongran Chi ◽  
Songtao Wang ◽  
Fengbo Wen ◽  
Guotai Feng
Keyword(s):  
Film Cooling ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Optimization Process ◽  
Pareto Optimal ◽  
Cooling Efficiency ◽  
Objective Functions ◽  
Nsga Ii ◽  
Aerodynamic Efficiency ◽  
Film Cooling Efficiency

In this paper, an optimization platform was established with Isight, cfx and the self-programming program which is used to generate the mesh. Film cooling effect can be taken into account. 15 parameters are selected as optimization variables. During the optimization process, the baseline blade and cooling holes are given by parameterized method. There are two objective functions during the optimization process. The first one is aerodynamic efficiency and the second one is film cooling efficiency. As there are two objective functions, NSGA-II is chosen as the multi-objective optimization algorithm. Then the Pareto-optimal front can be got. The results show that aerodynamic efficiency and film cooling efficiency restrict each other. It’s impossible to get the best solutions in one example, so the Pareto optimal set can provide a lot of choices. Different shapes make different effects on the aerodynamic efficiency and film cooling efficiency. From the above, it can be seen that the platform is helpful especially in the case that aerodynamic efficiency and film cooling efficiency restrict each other. This paper also discusses the prospects for platform applications.

scholarly journals FILM COOLING OVER A FLAT PLATE WITH COOLANT SUPPLY IN TO TRIANGULAR INDENTATION

2018 ◽  
Vol 40 (3) ◽  
pp. 5-11
Author(s):  
А.А. Khalatov ◽  
N.A. Panchenko ◽  
О.О. Petliak
Keyword(s):  
Coriolis Force ◽  
Film Cooling ◽  
High Performance ◽  
Turbine Blades ◽  
Engineering Thermophysics ◽  
Cooling Efficiency ◽  
National Academy Of Sciences ◽  
Peak Displacement ◽  
Sst Turbulence Model ◽  
Film Cooling Efficiency

The modern high-performance gas turbine engines operate at the flow temperatures exceeding the melting temperature of materials, which require the blade cooling. However, the traditional scheme of film cooling is characterized by appearance of secondary vortex structures that destroy the coolant film. From the existing alternative schemes of film cooling, which allow protecting the turbine blades from influence of high temperatures, the scheme with triangular dimples has demonstrated good results in the stationary conditions. This cooling scheme was patented and tested in the Institute of Engineering Thermophysics, National Academy of Sciences of Ukraine. In order to determine the feasibility of such a scheme, it is necessary to consider the effect of the blade rotation influencing the film cooling efficiency. The results are given towards theoretical investigation of the film cooling efficiency of this scheme under rotation conditions. The study was performed using the ANSYS CFX package using SST-turbulence model. The blowing ratio was varied from 0.5 to 2.0. Numerical simulation performed for rotation parameters corresponding to the dominant influence of the Coriolis force – 10, 100 rpm, and centrifugal forces – 3000, 5000 and 7000 rpm. Оn the basis of computer simulation, it has been shown that rotation does not affect weakly the average efficiency of film cooling at Coriolis force, but causes a peak displacement of local adiabatic efficiency, at rotation parameter of 7000 rpm, when there is a distortion of the flow lines.

Effects of a Groove Patterned Cooling Tube on the Film Cooling Performance of a Gas Turbine Blade

2017 ◽  
Author(s):  
Yeon-Ho Lee ◽  
Youn-Jea Kim
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Cooling Efficiency ◽  
Gas Turbine Blade ◽  
Cooling Performance ◽  
Cooling Tube ◽  
Film Cooling Efficiency

A high working fluid temperature in a gas turbine is required to improve its efficiency. However, high temperatures also reduce turbine blade durability. Film-cooling is one blade cooling method to control gas turbine blade temperature. In this study, film cooling performance was numerically investigated with various configurations of a groove patterned cooling tube. The CO2 blowing ratio of the cooling fluid was varied from 0.6 to 1.4 with 0.2 intervals. The numerical analysis was conducted using the ANSYS CFX ver. 16.1 commercial code. The film cooling efficiency and pressure distribution were graphically depicted and analyzed to derive the groove configuration with the highest film cooling efficiency. In particular, the flow field on the turbine blade with the circular groove configuration showed more uniform distribution compared to the reference model.

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