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Numerical investigation on adiabatic film cooling effectiveness and heat transfer coefficient for effusion cooling over a transverse corrugated surface

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Chinese Journal of Aeronautics 2017年第2期30卷 677-684页

作者： Qu Lihong Zhang Jingzhou Tan Xiaoming Wang Minmin College of Energy and Power Engineering Jiangsu Province Key Laboratory of Aerospace Power System Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100083 China

Three-dimensional numerical computations are conducted to investigate the effects of the blowing ratio and corrugation geometry on the adiabatic film cooling effectiveness as well as the heat transfer coefficient over a transverse corrugated *** is noticeable that the adiabatic wall temperature on the wavy valley of the transverse corrugated surface is relatively lower than that on the wavy *** corrugation has a relatively obvious influence on the laterallyaveraged adiabatic film cooling effectiveness in the region where the effusion film layer is developed,but has little influence in the front *** to a flat surface,the transverse corrugated surface produces a smaller adiabatic film cooling effectiveness and a higher heat transfer coefficient *** effusion cooling difference between the flat and corrugated surfaces behaves more obviously under a small aspect ratio of the wavy corrugation.

关键词： Adiabatic film cooling effectiveness effusion cooling Heat transfer Numerical computation Transverse corrugated surface

Isothermal study of effusion cooling flows using a large eddy simulation approach

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航空动力学报 2009年第4期24卷 729-739页

作者： W.P.Bennett J.J.Mc Guirk Aeronautical and Automotive Engineering Department Loughborough University

An isothermal numerical study of effusion cooling flow is conducted using a large eddy simulation(LES) *** main types of cooling are considered,namely tangential film cooling and oblique patch effusion *** represent tangential film cooling,a simplified model of a plane turbulent wall jet along a flat plate in quiescent surrounding fluid is *** contrast to a classic turbulent boundary layer flow,the plane turbulent wall jet possesses an outer free shear flow region,an inner near wall region and an interaction region,characterised by substantial levels of turbulent shear stress *** shear stress characteristics hold significant implications for RANS modelling,implications that also apply to more complex tangential film cooling flows with non-zero free stream *** LES technique used in the current study provides a satisfactory overall prediction of the plane turbulent wall jet flow,including the initial transition region,and the characteristic separation of the zero turbulent shear stress and zero shear strain *** effusion patch cooling is modelled using a staggered array of 12 rows of effusion holes,drilled at 30° to the flat plate *** effusion holes connect two channels separated by the flat ***,these comprise of a channel representing the combustion chamber flow and a cooling air supply channel.A difference in pressure between the two channels forces air from the cooling supply side,through the effusion holes,and into the combustion chamber *** from successive effusion rows coalesces to form an aerodynamic film between the combustion chamber main flow and the flat *** practical applications,this film is used to separate the hot combustion gases from the combustion chamber *** numerical model is shown to be capable of accurately predicting the injection,penetration,downstream decay,and coalescence of the effusion *** addition,the numerical model captures entrainmen

关键词： effusion cooling large eddy simulation isothermal analysis film cooling turbulent wall jet

Experiment on Adiabatic Film cooling Effectiveness in Front Zone of effusion cooling Configuration

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Transactions of Nanjing University of Aeronautics and Astronautics 2014年第3期31卷 338-344页

作者：杨志民张靖周 School of Energy and Power Engineering Beihang University Shenyang Engine Design and Research Institute Aviation Industry Corporation of China Jiangsu Province Key Laboratory of Aerospace Power System Nanjing University of Aeronautics and Astronautics Collaborative Innovation Center of Advanced Aero-engine

Experimental investigation is performed to investigate the cooling characteristics in the front zone of effusion configuration. Effects of blowing ratio,multi-hole arrangement mode,hole-to-hole pitch and jet orientation angle on the adiabatic film cooling effectiveness are concentrated on. The results show that the film layer displays an obvious"developing"feature in the front zone of effusion cooling scheme,for either the staggered or inline multi-hole arrangement. The varying gradient of the laterally-averaged adiabatic cooling effectiveness along the streamwise direction is greater for the staggered arrangement than that for the inline arrangement. The holes array arranged in staggered mode with small hole-tohole pitches is in favor of obtaining developed film coverage layer rapidly.

关键词： effusion cooling adiabatic film cooling effectiveness front zone cooling film development

Numerical study of effusion cooling on an adiabatic flat plate

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Propulsion and Power Research 2013年第4期2卷 269-275页

作者： Reaz Hasan Agin Puthukkudi Department of Mechanical&Construction Engineering Northumbria UniversityNewcastle Upon Tyne NE18STUnited Kingdom

The present study aims to investigate the effectiveness of effusion film cooling on an adiabatic flat *** holes of 301 inclination are used for supplying cold air to the hot primary flow.A non-dimensional parameter called the film cooling effectiveness is calculated for studying the influence of the velocity ratio for a continuous array of cooling holes.A new approach by splitting the full coverage of film holes into two zones of cooling rows is presented in this *** computational results from the investigation show that there exists strong relationship between velocity ratio and adiabatic film cooling *** simulations of two zones indicate that a careful analysis of the distribution of cooling holes can significantly reduce the demand for the supply of cold air.

关键词： Computational fluid dynamics(CFD) effusion cooling Film cooling Two zonescooling Adiabatic cooling effectiveness

Experimental Study on the Overall cooling Effectiveness of effusion-cooling Ceramic Matrix Composite Platform

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Journal of Thermal Science 2023年第3期32卷 1034-1048页

作者： DU Kun CHEN Qihao HUANG Xiaoyang LIANG Tingrui LIU Cunliang School Power and Energy Northwestern Polytechnical UniversityXi'an 710072China Yangtze River Delta Research Institute of NPU Northwestern Polytechnical UniversityTaicang 215400China Shaanxi Key Laboratory of Thermal Sciences in Aero-Engine System Northwestern Polytechnical UniversityXi'an 710129China NPU-KAI International Joint Laboratory of Advanced Aero-Engine Thermal Structure Northwestern Polytechnical UniversityXi'an 710129China AECC Sichuan Gas Turbine Establishment Chengdu 610500China

Ceramic matrix composite(CMC),with higher thermal limit and lower density relative to the superalloy,is regarded as the most important structural material for modern gas turbine ***,the anisotropic thermal conductivities caused by the weave patterns totally change the thermal conduction performance inside the solid ***,the present study aims to use the infrared thermographic to measure the SiC/SiC composite platform with staggered effusion holes along with the superalloy *** platform is prepared by 2-D plain weave braid structure with chemical vapor infiltration(CVI)*** temperature of mainstream is 900 K to match the real mainstream to coolant temperature ratio(T_(g)/T_(c)=1.5,2.1).The experimental was conducted with seven mass flow ratios(MFR=1.5%-4.5%).The results indicate that the thermal conductivity along the thickness direction is of great importance for the CMC *** superalloy platform obtains higher level of overall cooling effectiveness than CMC at T_(g)/T_(c)=***,the CMC platform achieves greater overall cooling effectiveness relative to superalloy at T_(g)/T_(c)=*** addition,CMC platform presents enhanced uniformity of overall cooling effectiveness due to the larger in-plane thermal conductivity.

关键词： conjugate heat transfer effusion cooling ceramic matrix composite temperature ratio

Influence of Multi-hole Arrangement on cooling Film Development

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Chinese Journal of Aeronautics 2012年第2期25卷 182-188页

作者： YANG Chengfeng ZHANG Jingzhou AVIC The First Aircraft Institute Xi＇ an 710089 China College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A series of computations is conducted for many multi-hole arrangements at several blowing ratios to further investigate the evolution of the film from multi-holes. The influence of multi-hole arrangement on effusion film cooling is analyzed and a preliminary relationship evaluating the film development from developing state to developed state is brought forward. Results show that the coolant jets from front rows of multi-holes merge rapidly and the strength of the kidney vortices due to mainstream-coolant jet interaction in the downstream region are mitigated under super-long-diamond arrangement where the streamwise hole-to-hole pitch is bigger than spanwise hole-to-hole pitch. The holes array arranged in super-long-diamond mode is not only in favor of obtaining developed film layer, but also improving averaged adiabatic film cooling effectiveness.

关键词： effusion cooling multi-hole arrangement cooling effectiveness film development numerical simulation