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Journal of.thermal Science 2012年第1期21卷 21-31页

作者： Davide Lengani Berardo Paradiso Andreas Marn inst. f. thermal turbomachinery and machine dynamics Graz University of Technology

This paper describes the measurements and the post-processing procedure adopted f.r the determination of.the turbulence intensity in a low pressure turbine (LPT) by means of.a single sensor f.st response aerodynamic pressure probe. The rig was designed in cooperation with MTU Aero Engines and considerable ef.orts were put into the adjustment of.all relevant model parameters. Blade count ratio, airf.il aspect ratio, reduced massf.ow, reduced speed, inlet turbulence intensity and Reynolds numbers were chosen to reproduce the f.ll scale LP turbine. Measurements were perf.rmed adopting a phase-locked acquisition technique in order to provide the time resolved f.ow f.eld downstream of.the turbine rotor. The total pressure random f.uctuations are obtained by selectively f.ltering, in the f.equency domain, the deterministic unsteadiness due to the rotor blades and coherent structures. The turbulence intensity is derived f.om the inverse f.urier transf.rm and the correlations between total pressure and velocity f.uctuations. The determination of.the turbulence intensity allows the discussion of.the interaction processes between the stator and rotor f.r engine-representative operating conditions of.the turbine.

关键词： Turbulence f.st response aerodynamic pressure probe low pressure turbine.

Ef.ects of.mid-passage gap with a variable surf.ce angle on a turbine vane endwall’s aerothermal and f.lm cooling perf.rmances

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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 inst.tute 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 manuf.ctured *** coolant f.om this gap is able to prevent hot mainst.eam ingression and provide cooling protection f.r 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 surf.ce angles is carried out in this *** endwall’s aerothermal and f.lm cooling perf.rmances under f.ur mid-passage gap modes at three typical mass f.ow ratio conditions are numerically *** indicate that under the traditional mid-passage mode,the coolant f.ows into the mainst.eam with a perpendicular incidence angle and can’t stick to the ***,cooling f.ilure occurs,and the endwall’s thermal load is badly *** f.lm cooling level at the suction-side endwall is improved when applying the mid-passage gap of.a 45surf.ce angle due to the secondary vortex being *** addition,when applying the mid-passage gap of.a 135surf.ce angle,the horseshoe vortex is pushed away,and the coverage area at the pressure-side endwall is enlarged *** best f.lm cooling perf.rmance is achieved when the upstream surf.ce angle is 135and the downstream surf.ce angle is 45due to the adiabatic f.lm cooling ef.ectiveness being increased at both the pressure-and suction-side *** the mass f.ow ratio is 1.5%,the coverage area is enlarged by 43%,and the area-averaged adiabatic f.lm cooling ef.ectiveness is increased by 37%,when compared with those under the traditional mid-passage mode.

关键词： f.lm cooling Heat transf.r Surf.ce angle Mid-passagegap Turbinevane endwall

Temperature f.uctuations and heat transport in partitioned supergravitational thermal turbulence

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Acta Mechanica Sinica 2024年第6期40卷 20-30页

作者： Dongpu Wang Jing Liu Rushi Lai Chao Sun Beijing Key Laboratory of.Space thermal Control Technology Beijing Institute of Spacecraft System EngineeringBeijing100094China Center f.r Combustion Energy Key Laboratory for Thermal Science and Power Engineering of MoEand Department of Energy and Power EngineeringTsinghua UniversityBeijing100084China Department of.Engineering Mechanics School ofAerospace EngineeringTsinghua UniversityBeijing100084China

We report an experimental study of.the local temperature f.uctuationsδT and heat transport in a partitioned supergravitational turbulent convection *** to the dynamics of.zonal f.ow in the normal system without partition walls,the probability density f.nction(PDf.at a position in the mixing zone exhibits a downward bending shape,suggesting that the multi-plume clustering ef.ect plays an important *** partitioned system,zonal f.ow is suppressed and the PDf. indicate that the single-plume ef.ect is ***,statistical analysis shows that the PDf.of.T is sensitive to ***,the thermal spectra f.llow P(f.∼f.(-5) in the normal system,which is relevant to the zonal *** absolute value of.the scaling exponent of.P(f.and the scaling range become small in the partitioned system,which provides another evidence f.r the inf.uence of.zonal f.ow on the energy ***,heat transf.r enhancement is f.und in the partitioned system,which may result f.om zonal f.ow being restricted and then f.cilitating the radial movement of.thermal plumes to the opposite conducting *** work may provide insights into the f.ow and heat transport control of.some engineering and geophysical f.ows.

关键词： Partitioned turbulent convection Supergravity Probability density f.nction Power spectra Heat transf.r

Temperature-Dependent Tearing Behavior of.Rubber Materials:Characterization and Modeling

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Acta Mechanica Solida Sinica 2024年第2期37卷 316-326页

作者： Qinyuan Yao f.ilong Zhang Pan Dong Ziyuan Zhao Yi He Weiguo Li Liming Chen State Key Laboratory of.Coal Mine Disaster dynamics and Control Chongqing UniversityChongqing400044China College of.Aerospace Engineering Chongqing UniversityChongqing400044China

With the increasingly widespread application of.rubber in many f.elds,there is a growing demand f.r quantitative characterization of.temperature-dependent mechanical properties in high-temperature service *** critical tearing energy is an important criterion f.r determining whether rubber materials will experience tearing inst.bility,while tear strength is a key parameter f.r rubber materials to resist *** is necessary to quantitatively characterize their evolution with *** theoretical research mainly relies on f.tting a large amount of.experimental data,which is not convenient f.r engineering ***,in this work,a temperature-dependent critical tearing energy model is f.rstly developed based on the f.rce-heat equivalence energy density *** model considers the equivalent relationship between the critical tearing energy required f.r crack inst.bility propagation and the thermal energy stored in the rubber *** is demonstrated that our model has higher prediction accuracy when compared to other ***,combining with the Grif.ith f.acture theory,temperature-dependent tear strength models applicable to three dif.erent crack modes are separately *** models are validated using experimental data f.r Mode I opening cracks and ModeⅢtearing cracks,and good consistency is ***,a quantitative analysis of.the inf.uence of.elastic modulus on tear strength at dif.erent temperatures is *** work provides a reliable way f.r predicting temperature-dependent tearing inst.bility behavior and of.ers benef.cial suggestions f.r improving the tear strength of.rubber materials at dif.erent temperatures.

关键词： Temperature-dependent Critical tearing energy Tear strength Rubber Theoretical model

Potential application of.radiant f.oor cooling systems f.r residential buildings in dif.erent climate zones

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Building Simulation 2024年第4期17卷 543-560页

作者： Mengying Cui Yang Song Yudong Mao Kaimin Yang Jiying Liu Zhe Tian School of.thermal Engineering Shandong Jianzhu UniversityJinan250101China School of.Environmental Science and Engineering Tianjin UniversityTianjin300072China Key Lab of.Building Environment and Energy of.Tianjin Tianjin UniversityTianjin300072China

A radiant f.oor cooling system(Rf.S)is a high-comf.rt and low energy consumption system suitable f.r residential *** f.oor systems usually work with f.esh air,and their operating perf.rmance is af.ected by climatic *** and outdoor environmental disturbances and the system’s control strategy af.ect the indoor thermal comf.rt and energy ef.iciency of.the ***,a multi-story residential building model was established in this *** system simulation program was used to study the operation dynamics of.three control strategies of.the Rf.S based on the calibrated ***,the perf.rmance of.the control strategies in f.ve climate zones in China were compared using multi-criteria decision-making in *** results show that control strategy has a negligible ef.ect on condensation risk,but the thermal comf.rt and economic perf.rmance dif.er f.r dif.erent control *** adaptability of.dif.erent control strategies varies in dif.erent climate zones based on the consideration of.multiple *** perf.rmance of.the direct-ground cooling source system is better in Hot summer and warm winter *** variable air volume control strategy scores higher in Serve cold and Temperate zones,and the hours exceeding thermal comf.rt account f.r less than 3%of.the total simulation ***,it is suggested to choose the Rf.S control strategy f.r residential buildings according to the climate zone characteristics,to increase the energy *** results provide a reliable ref.rence f.r implementing Rf.Ss in residential buildings.

关键词： control strategy radiant f.oor cooling system residential building energy ef.iciency climate zones

Uncertainty and disturbance estimator-based model predictive control f.r wet f.ue gas desulphurization system

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Chinese Journal of.Chemical Engineering 2024年第3期67卷 182-194页

作者： Shan Liu Wenqi Zhong Li Sun Xi Chen Raf.l Madonski School of.Energy and Environment Key Laboratory of Energy Thermal Conversion and Control of Ministry of EducationSoutheast UniversityNanjing 210096China f.culty of.Automatic Control Electronics and Computer ScienceSilesian University of TechnologyGliwise 44-100Poland

Wet f.ue gas desulphurization technology is widely used in the industrial process f.r its capability of.ef.icient pollution *** desulphurization control system,however,is subjected to complex reaction mechanisms and severe disturbances,which make f.r it dif.icult to achieve certain practically relevant control goals including emission and economic perf.rmances as well as system *** address these challenges,a new robust control scheme based on uncertainty and disturbance estimator(UDE)and model predictive control(MPC)is proposed in this *** UDE is used to estimate and dynamically compensate acting disturbances,whereas MPC is deployed f.r optimal f.edback regulation of.the resultant *** viewing the system nonlinearities and unknown dynamics as disturbances,the proposed control f.amework allows to locally treat the considered nonlinear plant as a linear *** obtained simulation results conf.rm that the utilization of.UDE makes the tracking error negligibly small,even in the presence of.unmodeled *** the conducted comparison study,the introduced control scheme outperf.rms both the standard MPC and PID(proportional-integral-derivative)control strategies in terms of.transient perf.rmance and ***,the results reveal that a lowpass-f.lter time constant has a signif.cant ef.ect on the robustness and the convergence range of.the tracking error.

关键词： Desulphurization system Disturbance rejection Model predictive control Uncertainty and disturbance estimator Nonlinear system

Heat Recuperation f.r the Self.Condensing CO_(2)Transcritical Power Cycle

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Journal of.thermal Science 2024年第5期33卷 1630-1641页

作者： PAN Lisheng SHI Weixiu SUN Yin SUN Yiwei WEI Xiaolin State Key Laboratory of.High-temperature Gas dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of.Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The supercritical CO_(2)Brayton cycle has potential to be used in electricity generation occasions with its advantages of.high ef.iciency and compact *** on a so-called self.condensing CO_(2)transcritical power cycle,a model was established and f.ur dif.erent layouts of.heat recuperation process were analyzed,a without-recuperation cycle,a post-recuperation cycle,a pre-recuperation cycle and a re-recuperation *** results showed that the internal normal cycle's share of.the whole cycle increases with increasing the cooling pressure and decreasing the f.nal cooled *** load in the supercritical heater decreases with increasing the cooling *** perspective of.perf.rmance,the re-recuperation cycle and the pre-recuperation cycle have similar thermal ef.iciency which is much higher than other two *** thermal ef.iciency and net power output have a maximum value with the cooling pressure,except in the condition with the f.nal cooled temperature of.31℃.Considering both the complexity and the economy,the pre-recuperation cycle is more applicable than the other *** 35℃of.the f.nal cooled temperature,the thermal ef.iciency of.the pre-recuperation cycle reaches the peak 0.34 with the cooling pressure of.8.4 MPa and the maximum net power output is 2355.24 kW at 8.2 MPa of.the cooling pressure.

关键词： CO_(2)transcritical power cycle heat recuperation process self.condensing

Impact of.Clocking on the Aero-Thermodynamics of.a Second Stator tested in a One and a Half.Stage HP Turbine

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Journal of.thermal Science 2008年第2期17卷 97-110页

作者： N.Billiard G.Paniagua R.Dénos turbomachinery and Propulsion Department von Karman inst.tute f.r f.uid dynamics

This paper f.cuses on the experimental investigation of.the time-averaged and time-accurate aero- thermodynamics of.a second stator tested in a 1.5 stage high-pressure turbine. The ef.ect of.clocking on aerodynamic and heat transf.r are investigated. Tests are perf.rmed under engine representative conditions in the VKI compression tube CT3. The test program includes f.ur dif.erent clocking positions, i.e. relative pitch-wise positions between the f.-st and the second stator. Probes located upstream and downstream of.the second stator provide the thermodynamic conditions of.the f.ow f.eld. On the second stator airf.il, measurements are taken around the blade prof.le at 15, 50 and 85% span with pressure sensors and thin-f.lm gauges. Both time-averaged and time-resolved aspects of.the f.ow f.eld are addressed. Regarding the time-averaged results, clocking ef.ects are mainly observed within the leading edge region of.the second stator, the largest ef.ects being observed at 15% span. The surf.ce static pressure distribution is changed locally, hence af.ecting the overall airf.il perf.rmance. f.r one clocking position, the thermal load of.the airf.il is noticeably reduced. Pressure f.uctuations are attributed to the passage of.the up- stream transonic rotor and its associated pressure gradients. The pattern of.these f.uctuations changes noticeably as a f.nction of.docking. The time-resolved variations of.heat f.ux and static pressure are analyzed together showing that the major ef.ect is due to a potential interaction. The time-resolved pressure distribution integrated along the second stator surf.ce yields the unsteady f.rces on the vane. The magnitude of.the unsteady f.rce is very dependent on the clocking position.

关键词： transonic f.ow turbines stator clocking f.rces heat transf.r.

Three-Dimensional Convection in an Inclined Porous Layer Subjected to a Vertical Temperature Gradient

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f.uid dynamics & Materials Processing 2024年第9期20卷 1957-1970页

作者： Ivan Shubenkov Tatyana Lyubimova Evgeny Sadilov Computational f.uid dynamics Laboratory Institute of Continuous Media Mechanics UB RASPerm614068Russia Theoretical Physics Department Perm State UniversityPerm614990Russia

In this paper,we study the onset and development of.three-dimensional convection in a tilted porous layer saturated with a *** layer is subjected to a gravitational f.eld and a strictly vertical temperature ***,problems of.thermal convection in tilted porous media saturated with a liquid are studied by assuming constant dif.erent temperatures at the boundaries of.the layer,which prevent these systems f.om supporting conductive(non-convective)*** boundary conditions considered in the present work allow a conductive state and are representative of.typical geological *** an earlier work,we carried out a linear stability analysis of.the conductive *** was shown that at any layer tilt angles,the most dangerous type of.disturbances are longitudinal ***,a non-zero velocity component exists in *** the present work,threedimensional non-linear convection regimes are *** original three-dimensional problem is reduced to two-dimensional one with an analytical expression f.r the velocity z-component v_(z)=v_(z)(x,y).It is shown that the critical Rayleigh number values obtained through numerical solutions of.the obtained 2D problem by a f.nite dif.erence method f.r dif.erent layer inclination angles,are in a good agreement with those predicted by the linear *** number of.convective rolls realized in nonlinear calculations also f.ts the linear theory predictions f.r a given cavity *** carried out at low supercriticalities show that a direct bif.rcation takes *** increasing supercriticality,no transitions to other convective regimes are *** situation studied in this problem can be observed in oil-bearing rock f.rmations under the inf.uence of.a geothermal temperature gradient,where the ensuing f.uid convection can af.ect the distribution of.oil throughout the layer.

关键词： thermal convection inclined layer porous media vertical temperature gradient

thermal History of.Cambrian Burgess Shale-Type Deposits:New Insights f.om the Early Cambrian Chengjiang and Qingjiang f.ssils of.South China

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Journal of.Earth Science 2024年第4期35卷 1215-1223页

作者： Yuheng Qiao Linhao Cui Guangyuan Xing Dongjing f. Chao Chang Robert Gaines Xingliang Zhang State Key Laboratory of.Continental dynamics Shaanxi Key laboratory of Early Life and EnvironmentsDepartment of GeologyNorthwest UniversityXi’an710069China Department of.Geology Pomona CollegeClaremontCA91711USA

Burgess Shale-type deposits provide a wealth of.inf.rmation on the early evolution of.*** that are central to understanding the exceptional preservation of.these biotas and the paleoenvironments they inhabited may be obscured by the post-depositional alteration due to metamorphism at depth and weathering near the Earth’s *** over 50 Cambrian BST biotas,the Chengjiang and Qingjiang deposits are well known f.r their richness of.sof.-bodied taxa,f.delity of.preservation,and Early Cambrian *** alteration via weathering has been well-investigated,the thermal maturity of.the units bearing the two biotas has not yet been *** we investigate peak metamorphic temperatures of.the two deposits using two independent *** gradient analyses demonstrate that the most f.ssilif.rous sections of.the Chengjiang were buried at a maximum depth of.8500 m in the Early Triassic,corresponding to∼300°C,while the type area of.the Qingjiang biota was buried at a maximum depth of.8700 m in the Early Jurassic,corresponding to∼240°*** geothermometer analyses of.f.ssil carbonaceous material demonstrate that peak temperatures varied across localities with dif.erent burial *** two productive sections of.the Chengjiang biota were thermally altered at a peak temperature of.approximately 300°C,and the main locality of.the Qingjiang biota experienced a peak temperature of.238±22°*** results f.om two independent methods are *** BST deposits f.r which thermal maturity has been documented,the Qingjiang biota is the least thermally mature,and theref.re holds promise f.r enriching our understanding of.BST deposits.

关键词： the Chengjiang Biota the Qingjiang Biota burial history Raman geothermometer thermal history Burgess Shale-type Lagerstätte