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Novel Shaped Sweeping Jet for Improved Film Cooling and Anti-Deposition Performance

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Journal of Thermal Science 2024年第06期33卷 2089-2096页

作者： ZHOU Wenwu WANG Kechen ZHANG Tianluan WEN Xin PENG Di liu yingzheng Key Lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong University Gas Turbine Research Institute Shanghai Jiao Tong University

The present study proposed a shaped sweeping jet(SJ) that possesses the merits of both SJ and shaped hole,which demonstrates significantly improved cooling effectiveness and anti-deposition *** to a classical 777 shaped hole,the shaped SJ exhibits a maximum enhancement of 70% in cooling effectiveness and a maximum reduction of 28% in particle deposition height,*** to the periodic oscillation of coolant jet and higher streamwise jet momentum,the shaped SJ can provide much wider coolant coverage and therefore sweep the adhesive particle away from the *** study is the first attempt to reconcile the performance of film cooling and particle anti-deposition simultaneously,which offers a promising design concept for future engine cooling.

关键词： film cooling multi-perspective scanning particle deposition pressure sensitive paint sweeping jet

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斜坡流动分离数据同化和多工况泛化研究

水动力学研究与进展（A辑） 2024年第3期39卷 303-312页

作者：伍荣李志阳何创新刘应征上海交通大学动力机械与工程教育部重点实验室上海200240

为准确预测不同倾角斜坡面上的流场特性,该文采用集合卡尔曼滤波方法对剪切应力输运模型常数进行数据同化的优化,得到一套适用于多工况参数下的流场计算预测方案。首先,利用粒子图像测速法对高、中和低三组不同坡度的斜坡模型在雷诺数Re... 详细信息

为准确预测不同倾角斜坡面上的流场特性,该文采用集合卡尔曼滤波方法对剪切应力输运模型常数进行数据同化的优化,得到一套适用于多工况参数下的流场计算预测方案。首先,利用粒子图像测速法对高、中和低三组不同坡度的斜坡模型在雷诺数Re=38100、Re=57200和Re=85800下的分离流动进行了实验测量,以测得的若干下游位置处时均流向速度分布作数据同化的实验观测,分析了单模型工况下,不同位置处的观测数据对流场同化的影响。随后,该文以中坡度中等雷诺数下的同化模型常数对其他坡度和雷诺数下的流场进行了拓展计算,分析并验证了该数据同化模型在多工况参数下的泛化能力。研究表明:在不同坡度和雷诺数下,中坡度Re=57200条件下同化获得的模型常数对坡度和雷诺数泛化的效果最好,可认为该套模型常数适用于该文研究的所有工况和参数;相较于原始模型,同化后流场的涡黏分布主要集中在斜坡中下游位置,泛化后再计算发现在坡面的中下游位置涡流黏度分布整体上小于原始模型常数计算结果。

关键词：数据同化集合卡尔曼滤波模型常数优化流动分离 PIV测量

Thermal stability improvement of sprayable fast-responding pressure-sensitive paint for measurement above 100℃

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Chinese Journal of Aeronautics 2021年第1期34卷 320-326页

作者： Di PENG Feng GU Zhe ZHONG yingzheng liu Key Lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Gas Turbine Research Institute Shanghai Jiao Tong UniversityShanghai 200240China

The thermal stability of sprayable fast-responding Pressure-Sensitive Paint(fast PSP)was investigated to explore the possibility for application in turbomachinery and hypersonic research with temperature above 100℃.The first part of the study focused on a widely-used Polymer Ceramic PSP(PC-PSP).The effects of thermal degradation on its key sensing properties,including luminescent intensity,pressure sensitivity and response time,were examined for a temperature range from 60 to 100℃.Severe degradation in intensity and pressure sensitivity was found as temperature reached 70℃or higher,which would cause failure of PSP application in these ***,a fast-responding Mesoporous-Particle PSP(MP-PSP)was developed which did not show degradation effects until 140℃.The greatly improved thermal stability of MP-PSP was attributed to:selection of polymer with higher glass transition temperature(polystyrene)to delay the saturation effect of oxygen quenching as temperature increased;porous and hollow structure of particles for luminophore deposition that minimizes polymer–luminophore *** new paint formulation has significantly raised the upper temperature limit of fast PSP and offers more opportunities for applications in harsh environment.

关键词： Dynamic response Polymer–luminophore interaction Pressure sensitivity Pressure-sensitive paint Thermal degradation

Jet sweeping angle control by fluidic oscillators with master-slave designs

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Chinese Journal of Aeronautics 2021年第5期34卷 145-162页

作者： Ziyan LI Kaiwen ZHOU yingzheng liu Xin WEN Key Lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Gas Turbine Research Institute Shanghai Jiao Tong UniversityShanghai 200240China

The fluidic oscillator is an instrument that can continuously generate a spatially sweeping jet entirely based on its internal geometry without any moving ***,the traditional fluidic oscillator has an inherent limitation,that is,the spreading angle cannot be controlled independently,rather by the jet volume flow rate and internal ***,two types of fluidic oscillators based on the master-slave design are developed in current study to decouple this *** both designs,the master layer inherits the similar oscillation mechanisms of a sweeping jet,and the slave layer resembles a steady jet *** difference between the two designs is that Design A has a short diverging exit in the slave layer,but Design B adds a long interaction chamber in the exit channel to intensify flow *** external flow fields and governing oscillation properties of these two designs are experimentally explored with time-resolved Particle Image Velocimetry(PIV),while the internal flow dynamics and driving oscillation mechanisms are numerically *** fixing the total volume flow rate,the jet spreading angle of Design A can be increased smoothly from 0°to above 100°by increasing the proportion of master layer’s flow rate from 0 to 100%.For Design B,the control authority of the master layer is significantly enhanced by adding the interaction chamber in the slave *** addition,the added chamber causes notable jet oscillation even when the master layer has none input.

关键词： Adjustable spreading angle CFD Fluidic devices Master-slave fluidic oscillator TR-PIV

Numerical Study on Effect of Non-uniform CMAS Penetration on TGO Growth and Interface Stress Behavior of APS TBCs

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Chinese Journal of Mechanical Engineering 2021年第6期34卷 98-113页

作者： Zhenwei Cai Zifan Zhang yingzheng liu Xiaofeng Zhao Weizhe Wang Key Laboratory of Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China Gas Turbine Research Institute Shanghai Jiao Tong UniversityShanghai200240China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240China

The penetration of CaO-MgO-Al_(2)O_(3)-SiO_(2)(CMAS)is one of the most significant factors that induce the failure of air-plasma-sprayed thermal barrier coatings(APS TBCs).The direct penetration of CMAS changes the thermal/mechanical properties of the top coat(TC)layer,which affects the thermal mismatch stress behavior and the growth of thermally grown oxide(TGO)at the TC/bond coat(BC)interface,thereby resulting in a more complicated interface stress *** the present study,a two-dimensional global model of APS TBCs with half of the TC layer penetrated by CMAS is established to investigate the effect of non-uniform CMAS penetration on the interface stress ***,a local model extracted from the global model is established to investigate the effects of interface morphologies and CMAS penetration *** results show that non-uniform CMAS penetration causes non-uniform TGO growth in APS TBCs,which consequently causes the stress behavior to vary along the ***,the CMAS pen-etration depth imposes a significant effect on the TC/TGO interface stress behavior,whereas the interface roughness exerts a prominent effect on the stress level at the BC/TGO interface under CMAS *** study reveals the mechanism associated with the effect of non-uniform CMAS penetration on the interface stress behavior in APS TBCSs.

关键词： CMAS non-uniform penetration TGO growth Interface stress CMAS penetration depth Interface roughness

Improved Turbine Vane Endwall Film Cooling by Using Sand-Dune-Inspired Design

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Journal of Thermal Science 2022年第3期31卷 958-973页

作者： ZHOU Wenwu SHAO Hongyi QENAWY Mohamed PENG Di HU Hui liu yingzheng Key Lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China Gas Turbine Research Institute Shanghai Jiao Tong UniversityShanghai200240China Department of Aerospace Engineering Iowa State UniversityAmesIA50011USA

As continuous of the previous sand-dune-inspired design,the Barchan-Dune-Shaped Injection Compound(BDSIC)’s film cooling performance at the endwall region was further investigated both experimentally and *** the public 777-shaped hole was served as a baseline,the BDSIC’s endwall effectiveness was assessed at various blowing *** were performed in a single-passage transonic wind tunnel using pressure-sensitive paint(PSP)*** dioxide was used as coolant with density ratio of DR=*** purge slot’s blowing ratio was fixed at M=0.3,but the coolant holes were adjusted within M=0.5–*** measured experimental results indicate that the film distribution at the endwall is strongly affected by the passage flow *** BDSIC holes demonstrate much higher film effectiveness than the 777-shaped holes for all blowing ratios,~30%enhancement for regionally averaged effectiveness at M=1.0 and~26%at M=*** shown by the numerical results,the existence of BDSIC reduced the coolant penetration effect at a higher blowing *** was deflected and its momentum increased in the streamwise direction,therefore providing more robust film coverage over the endwall *** anti-counter-rotating vortex pair induced by the BDSIC further stabilized the coolant film and increased the coolant spreading downstream.

关键词： endwall film cooling pressure-sensitive paint Barchan dune 777-shaped hole counter-rotating vortex

Ambient flash sintering of reduced graphene oxide/zirconia composites:Role of reduced graphene oxide

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Journal of Materials Science & Technology 2021年第1期60卷 70-76页

作者： Weiwei Xiao Na Ni Xiaohui Fan Xiaofeng Zhao yingzheng liu Ping Xiao Gas Turbine Research Institute School of Mechanical EngineeringShanghai Jiao Tong University800 Dongchuan RdShanghai 200240China School of Materials Science and Engineering Shanghai Jiao Tong University800 Dongchuan RdShanghai 200240China

Fabrication of graphene/ceramic composites commonly requires a high-temperature sintering step with long times as well as a vacuum or inert atmosphere,which not only results in property degradation but also significant equipment complexity and manufacturing *** this work,the ambient flash sintering behavior of reduced graphene oxide/3 mol% yttria-stabilized ZrO_(2)(rGO/3 YSZ) composites utilizing rGO as both a composite component and a conductive additive is *** the sintering condition is carefully optimized,a dense and conductive composite can be achieved at room temperature and in the air within 20 *** role of the rGO in the FS of the rGO/3 YSZ composites is elucidated,especially with the assistance of a separate investigation on the thermal runaway behavior of the *** work suggests a promising fabrication route for rGO/ceramic composites where the vacuum and furnace are not needed,which is of interest in terms of simplifying the fabrication equipment for energy and cost savings.

关键词： Flash sintering Reduced graphene oxide Zirconia Ceramic matrix composites

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翼型流动分离的EnKF非稳态数据同化

气体物理 2024年第3期9卷 35-45页

作者：张禹瑶何创新刘应征上海交通大学机械与动力工程学院动力机械与工程教育部重点实验室上海200240 上海交通大学燃气轮机研究院上海200240

为了改善RANS模型对流动分离现象的预测性能,针对NACA0012翼型绕流,采用基于非稳态计算的集合Kalman滤波(ensemble Kalman filter,EnKF)数据同化方法,结合粒子图像测速(particle image velocimetry,PIV)数据对SST湍流模型的模型常数进... 详细信息

为了改善RANS模型对流动分离现象的预测性能,针对NACA0012翼型绕流,采用基于非稳态计算的集合Kalman滤波(ensemble Kalman filter,EnKF)数据同化方法,结合粒子图像测速(particle image velocimetry,PIV)数据对SST湍流模型的模型常数进行了修正,对比分析了不同模型常数扰动幅度、不同集合样本数目下稳态数据同化和非稳态数据同化的预测结果差异。研究结果表明,相对于稳态计算,非稳态计算能够增强数值模拟的稳健性,从而可以在较大的扰动幅度下,改善RANS模型的初始预测分布。稳态数据同化在模型常数扰动幅度较大或者样本数目较少时存在明显缺陷,非稳态的数据同化具有更好的鲁棒性,能够在更大扰动幅度和更少样本数下得到最优的湍流模型常数,对流场的预测更加准确。

关键词：非稳态数据同化集合Kalman滤波流动分离模型常数优化翼型

Noise reduction for temperature-sensitive paint measurement contaminated by strong background radiation in a high enthalpy hypersonic tunnel

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Acta Mechanica Sinica 2021年第1期37卷 20-26,I0002页

作者： Di Peng Xu liu Lingrui Jiao Ziyan Li Xin Wen Chaokai Yuan Guilai Han Yunfeng liu yingzheng liu Zonglin Jiang Gas Turbine Research Institute/School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai200240China Institute of Mechanics Chinese Academy of SciencesBeijing100190China

The strong background radiation in high enthalpy hypersonic shock tunnels has posed severe challenges for measurement using luminescent *** proposed a solution for reducing background radiation from time-resolved temperature-sensitive paint(TSP)measurement in a hypersonic flow with Ma=6.5 and T_(0)=3525 *** TSP was applied on an inlet ramp model,and the images were taken by a high-speed camera at 2 kHz under a modulated *** strong background radiation led to a low signal-to-noise ratio and significant errors for the first half of the 130-ms test ***,three noise reduction methods were developed and evaluated based on temporal reconstruction,spatial reconstruction and robust principal component analysis(RPCA),*** RPCA method showed the best performance that successfully recovered high-quality TSP data for a majority of test duration(t≥40 ms).

关键词： Temperature-sensitive paint Time-resolved measurement Hypersonic flow Background radiation