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Chinese Journal of Aeronautics 2024年第6期37卷 20-37页

作者： Zhiyu LI Kaiyuan ZHANG Zhigang LI Jun LI Institute of Turbomachinery Xi’an Jiaotong UniversityXi’an 710049China

The mid-passage gap is an inevitable structure in a vane passage due to turbine vanes being manufactured *** coolant from this gap is able to prevent hot mainstream ingression and provide cooling protection for the endwall.A novel idea of enlarging the endwall’s coverage area and reducing the endwall’s thermal load by applying the mid-passage gap with variable surface angles is carried out in this *** endwall’s aerothermal and film cooling performances under four mid-passage gap modes at three typical mass flow ratio conditions are numerically *** indicate that under the traditional mid-passage mode,the coolant flows into the mainstream with a perpendicular incidence angle and can’t stick to the ***,cooling failure occurs,and the endwall’s thermal load is badly *** film cooling level at the suction-side endwall is improved when applying the mid-passage gap of a 45surface angle due to the secondary vortex being *** addition,when applying the mid-passage gap of a 135surface angle,the horseshoe vortex is pushed away,and the coverage area at the pressure-side endwall is enlarged *** best film cooling performance is achieved when the upstream surface angle is 135and the downstream surface angle is 45due to the adiabatic film cooling effectiveness being increased at both the pressure-and suction-side *** the mass flow ratio is 1.5%,the coverage area is enlarged by 43%,and the area-averaged adiabatic film cooling effectiveness is increased by 37%,when compared with those under the traditional mid-passage mode.

关键词： film cooling Heat transfer Surface angle Mid-passagegap Turbinevane endwall

film cooling Effectiveness Superposition Calculation of Double-Row Injection Holes on Turbine Vane

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Journal of Thermal Science 2022年第6期31卷 2424-2437页

作者： XU Zhipeng ZHU Huiren LIU Cunliang YE Lin ZHOU Daoen School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China Shaanxi Key Laboratory of Thermal Sciences in Aero-engine System Xi'an 710129China

film cooling effectiveness superposition of double-row injection holes on the turbine vane was studied by infrared temperature measurement experiment. The Sellers superposition method and a modified Sellers method were adopted for dustpan-shaped hole and cylindrical hole. Numerical simulations were implemented to analyze the film superposition mechanism. It is found that the Sellers method is more accurate on the suction side than the pressure side. Injection film of the two types of holes exhibits different superposition modes. Cylindrical hole are “blocky-like” superposition. Dustpan-shaped hole are “sheet-like” superposition. The counter-rotating vortex pairs and separation of the film are the main factors affecting the accuracy of Sellers film superposition method. The modified method can significantly improve the superposition prediction accuracy for almost all situations. The modified method reduces superposition errors from 28% to 3% for the cylindrical hole, and from 42% to 13% for the dustpan-shaped hole on the suction side. It reduces superposition errors from 30% to 8% for the cylindrical hole, and from 23% to 15% for the dustpan-shaped hole on the pressure side.

关键词： film cooling superposition calculation shaped hole infrared temperature measurement numerical simulation

film cooling performance and flow structure of single-hole and double-holes with swirling jet

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Chinese Journal of Aeronautics 2022年第3期35卷 201-213页

作者： Rui ZHU Simon TERRENCE Shulei LI Gongnan XIE School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China Department of Mechanical Engineering University of MinnesotaMinneapolisMN 55455USA School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China

This paper presents the results of a numerical study of the effects of swirling flow in coolant jets on film cooling *** combined-hole designs with swirling coolant flow entering the delivery hole are proposed and *** film cooling effectiveness values for cases with various blowing ratios are *** flow structures and underlying mechanisms are *** results show that film cooling effectiveness is improved with jet swirl at high blowing ratios,and that swirl strength has significant influence on film cooling ***-hole designs can further improve film cooling performance using swirling jets due to mixing of coolant flows and interaction of *** largest improvements of area-averaged film cooling effectiveness for a single-hole swirl case and a combined-hole swirl case over corresponding non-swirling case results are 157%and 173%,respectively.

关键词： Combined-hole film cooling Interactions of vortices Jet-in-cross-flow Swirling flow

film cooling Performance of a Row of Dual-fanned Holes at Various Injection Angles

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Journal of Thermal Science 2017年第5期26卷 453-458页

作者： LI Guangchao WANG Haofeng ZHANG Wei KOU Zhihai XU Rangshu Faculty of Aerospace Engineering Shenyang Aerospace University Shenyang China 110136

film cooling performance about a row of dual-fanned holes with injection angles of 30°, 60 ° and 90° were experimentally investigated at blowing ratios of 1.0 and 2.0. Dual-fanned hole is a novel shaped hole which has both inlet expansion and outlet expansion. A transient thermochromic liquid crystal technique was used to reveal the local values of film cooling effectiveness and heat transfer coefficient. The results show that injection angles have strong influence on the two dimensional distributions of film cooling effectiveness and heat transfer coefficient. For the small injection angle of 30 degree and small blowing ratio of 1.0, there is only a narrow spanwise region covered with film. The increase of injection angle and blowing ratio both leads to the enhanced spanwise film diffusion, but reduced local cooling ability far away from the hole. Injection angles have comprehensive influence on the averaged film cooling effectiveness for various x/d locations. As injection angles are 30 and 60 degree, two bands of high heat transfer coefficients are found in mixing region of the gas and coolant. As injection angle increases to 90 degree, the mixing leads to the enhanced heat transfer region near the film hole. The averaged heat transfer coefficient increases with the increase of injection angle.

关键词： gas turbine film cooling dual-fanned hole thermochromic liquid crystal technique

Improving film cooling Performance by Using One-Inlet and Double-Outlet Hole

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Journal of Thermal Science 2010年第5期19卷 430-437页

作者： Guang-chao Li and Wei Zhang Aeroengine and Energy Engineering College,Shenyang Areospace University Shenyang China 110136 Aeroengine and Energy Engineering College Shenyang Areospace University Shenyang China

The film cooling performance of a trunk-branch hole is investigated by numerical simulation in this paper. The geometry of the hole is a novel cooling concept, which controls the vortices-pair existing at the mink hole outlet using the injection of the branch hole. The trunk-branch holes require easily machinable round hole as compared to the shaped holes. The flow cases were considered at the blowing ratios of 0.5, 0.75, 1.0, 1.5 and 2.0. At the low blowing ratio of 0.5, the vortices-pair at the outlet of the trunk hole is reduced and the laterally coverage of the film is improved. At the high blowing ratio of 2.0, the vortices-pair is killed by the vortex which is produced by the injection of the branch hole. The flow rate of the two outlets becomes more significantly different when the blowing ratio increases from 0.75 to 2.0. The discharge coefficients increase 0.15 and the laterally averaged film effectiveness improve 0.2 as compared to the cylindrical holes. The optimal blowing ratios occur at M=1.0 or M= 1.5 according to the various locations downstream of the holes.

关键词： aerospace propulsion system gas turbine film cooling heat transfer

Interpretation of gas-film cooling against aero-thermal heating for high-speed vehicles

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Applied Mathematics and Mechanics(English Edition) 2016年第12期37卷 1615-1630页

作者： Ming DONG Department of Mechanics Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin 300072China

The possible application of the film-cooling technique against aero-thermal heating for surfaces of high-speed flying vehicles is discussed. The technique has been widely used in the heat protection of gas turbine blades. It is shown in this paper that, by applying this technique to high-speed flying vehicles, the working principle is fundamentally different. Numerical simulations for two model problems axe performed to support the argument. Besides the heat protection, the appreciable drag reduction is found to be another favorable effect. For the second model problem, i.e., the gas cooling for an optical window on a sphere cone, the hydrodynamic instability of the film is studied by the linear stability analysis to observe possible occurrence of laminar-turbulent transition.

关键词： film cooling aero-thermal heating numerical simulation laminar-turbulenttransition linear stability analysis

Experimental Study on the film cooling Characteristics of Three Complex Tip Structures

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Journal of Thermal Science 2023年第4期32卷 1378-1392页

作者： LIN Juqiang LI Haiwang YOU Ruquan LIU Runzhou TAO Zhi LIU Song School of Energy and Power Engineering Beihang UniversityBeijing100191China Research Institute for Aero-Engines Beihang UniversityBeijing100191China National Key Laboratory of Science and Technology on Aero Engines Aero-thermodynamics Beijing100191China AECC Sichuan Gas Turbine Establishment Sichuan610500China

The turbine blades of aircrafts must be properly cooled to prevent engine ***,to investigate the influence of the tip structure on the film cooling effect,pressure-sensitive paint test technology was used to determine the adiabatic film cooling effectiveness in this *** experiment was completed in a cascade comprising three straight *** effects of the blowing ratio,density ratio,tip clearance,and tip structure on film cooling efficiency were *** experimental results demonstrated that,as the blowing ratio increased,the film coverage area and film cooling efficiency increased under most experimental ***,the film cooling efficiency was found to initially increase,and subsequently decrease,as the blowing ratio *** respective influences of the density ratio and tip clearance on the film cooling efficiency were found to be *** density ratio experiments revealed that a high-density ratio can result in better film coverage than the low-density-ratio *** tip clearance experimental results indicated that a small tip clearance promotes an increase in film cooling efficiency;this is because the small tip clearance negatively affects the main stream leakage flow,which can reduce the film coverage *** the conditions of the Base case 2 configuration,a blowing ratio of 2.1,and a tip clearance of 0.6%h,the average film cooling efficiency of the blade tip was *** the three blade tip structures applied in this study,Base case 2 demonstrated higher film cooling efficiency than the other two blade tip structures under the conditions of the same blowing ratio,tip clearance,and density ratio.

关键词： film cooling tip structure pressure-sensitive paint leakage flow

Experimental investigation of the full coverage film cooling effectiveness of a turbine blade with shaped holes

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Chinese Journal of Aeronautics 2022年第3期35卷 297-308页

作者： Cunliang LIU Fan ZHANG Shuaiqi ZHANG Qingqing SHI Hui SONG School of Power and Energy Northwestern Polytechnical UniversityXi'an 710129China Shaanxi Key Laboratory of Thermal Sciences in Aero-engine System Xi'an 710129China Beijing Institute of Radio Measurement Beijing 100854China

The film cooling effectiveness of two turbine blades at different turbulence intensities(0.62%and 16.00%)and mass flux ratios(2.91%,5.82%,8.73%and 11.63%)is studied by using the Pressure-Sensitive Paint(PSP)measurement *** are a baseline and an improved turbine blade in current work,and their film cooling hole position distribution is the *** the hole shape on suction surface and pressure surface is changed from cylindrical hole(baseline)to laid-back fan-shaped hole(improved blade).Both blades have 5 rows of cylindrical holes at the leading edge and 4 rows of cooling-holes on the suction surface and the pressure *** experimental results show that the film cooling effectiveness of the improved blade is much better than the *** increase in turbulence intensity will reduce the cooling effectiveness on the surface of turbine blade,but the effect of turbulence intensity becomes weaker with an increase in the mass flux *** with the multiple rows of cylindrical holes,the cooling effectiveness of shaped holes is more influenced by the turbulence intensity at low mass flux ratio.

关键词： Adiabatic film cooling effectiveness film cooling Shaped holes Turbine blade Turbulence intensity

A numerical study of segmented cooling-stream injection in supersonic film cooling

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Chinese Journal of Aeronautics 2022年第6期35卷 156-171页

作者： Hang NI Mingjun WANG Peixue JIANG Wei PENG Yinhai ZHU Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China School of Nuclear Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Department of Energy and Power Engineering Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationTsinghua UniversityBeijing 100084China Tsinghua University-Zhang Jiagang Joint Institute for Hydrogen Energy and Lithium-Ion Battery Technology Tsinghua UniversityBeijing 100084China

The present study proposes a segmented cooling-stream injection structure based on a certain coolant mass flow rate,and numerically investigates the effect of segmented cooling-stream injection on supersonic film *** results indicate that without shock-wave impingement and with helium as the coolant,segmented cooling-stream injection can reduce the mixing between the mainstream and the cooling stream to produce better cooling performance than single injection,especially at larger coolant Mach ***,with nitrogen as the coolant,the cooling effect of the segmented-injection system is very close to that of the single-injection *** at the impinging region is enhanced significantly when there is an incident shock *** the shock wave impinges between the two coolant inlets,segmented cooling-stream injection improves film cooling effectiveness in the midstream and downstream regions more than single injection because only part of the cooling stream undergoes the enhanced mixing effect of the shock *** advantage of segmented injection is reduced when the impinging region is behind the second coolant *** further downstream the impinging region,the smaller the associated advantage.

关键词： film cooling Mach number Segmented injection Shock wave Supersonic flow

Effects of Chemical Reaction Caused by cooling Stream on film cooling Effectiveness

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Journal of Thermal Science 2012年第1期21卷 60-65页

作者： Keyong Cheng Shiqiang Liang Xiulan Huai Wei Chen Yongxian Guo Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100049 China School of Mechano-electronic Engineering Xidian University Xi’an 710071 Shaanxi China

With the increase of inlet temperature of gas turbines, the benefits by using the conventional methods are likely to approach their limits. Therefore, it is essential to study novel film cooling methods for surpassing these current limits. Based on the theory of heat transfer enhancement, a film cooling method with chemical reaction by cool- ing stream is proposed. In order to test the feasibility of the proposed method, numerical simulations have been conducted. The classic flat plate structure with a 30 degree hole is used for the simulation. In the present study, the effects of the parameters in relation to the chemical reaction on film cooling effectiveness, such as chemical heat sink, volume changes, and reaction rate, are investigated numerically. The conventional film cooling is also calculated for the comparison. The results show that film cooling effectiveness is improved obviously due to the chemical reaction, and the reaction heat and reaction rate of cooling stream have an important effect on film ef- fectiveness. However, the effect of volume changes can be ignored.

关键词： Gas turbine film cooling Chemical reaction Heat transfer Numerical simulation