scholarly journals Film Cooling in Rocket Nozzles

2020 ◽  
pp. 65-78
Author(s):  
Sandra Ludescher ◽  
Herbert Olivier
Keyword(s):  
Experimental Data ◽  
Parametric Study ◽  
Film Cooling ◽  
Rocket Engine ◽  
Cooling Efficiency ◽  
Conical Nozzle ◽  
Hot Gas ◽  
Dual Bell ◽  
Film Cooling Efficiency ◽  
Cooling Model

Abstract In this project supersonic, tangential film cooling in the expansion part of a nozzle with rocket-engine like hot gas conditions was investigated. Therefore, a parametric study in a conical nozzle was conducted revealing the most important influencing parameter on film cooling for the presented setup. Additionally, a new axisymmetric film cooling model and a method for calculating the cooling efficiency from experimental data was developed. These models lead to a satisfying correlation of the data. Furthermore, film cooling in a dual-bell nozzle performing in altitude mode was investigated. The aim of these experiments was to show the influence of different contour inflection geometries on the film cooling efficiency in the bell extension.

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

scholarly journals Numerical Prediction of Film Cooling Effectiveness and the Associated Aerodynamic Losses With a Three-Dimensional Calculation Procedure

1990 ◽  
Author(s):  
G. H. Dibelius ◽  
R. Pitt ◽  
B. Wen
Keyword(s):  
Experimental Data ◽  
Film Cooling ◽  
Reverse Flow ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Temperature Pattern ◽  
Main Stream ◽  
Cooling Efficiency ◽  
Film Cooling Effectiveness ◽  
Aerodynamic Losses

Film cooling of turbine blades by injecting air through holes or slots affects the main stream flow. A numerical model has been developed to predict the resulting three-dimensional flow and the temperature pattern under steady flow conditions. An elliptic procedure is used in the near injection area to include reverse flow situations, while in the upstream area as well as far downstream a partial-parabolic procedure is applied. As first step an adiabatic wall has been assumed as boundary condition, since for this case experimental data are readily available for comparison. At elevated momentum blowing rates, zones of reverse flow occur downstream of the injection holes resulting in a decrease of cooling efficiency. A variation of the relevant parameters momentum blowing rate m, injection angle α and ratio of hole spacing to diameter s/d revealed the combination of m ≈ 1, α ≈ 30° and s/d ≈ 2 to be the optimum with respect to the averaged cooling efficiency and to the aerodynamic losses. Cooling is more efficient with slots than with a row of holes not considering the related problems of manufacture and service life. The calculated temperature patterns compare well with the experimental data available.

Parametric study of supersonic film cooling in dual bell nozzle for an experimental air–kerosene engine

2018 ◽  
Vol 78 ◽  
pp. 364-376 ◽  
Author(s):  
Siba Prasad Choudhury ◽  
Abhilash Suryan ◽  
J.C. Pisharady ◽  
A. Jayashree ◽  
Khalid Rashid
Keyword(s):  
Parametric Study ◽  
Film Cooling ◽  
Dual Bell

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.

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