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Verification and validation of URANS simulations of the turbulent cavitating flow around the hydrofoil

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Journal of Hydrodynamics 2017年第4期29卷 610-620页

作者：龙云龙新平季斌槐文信钱忠东 State Key laboratory of water Resources and Hydropower Engineering science Wuhan University Hubei Key laboratory of waterjet Theory and New technology School of Power and Mechanical EngineeringWuhan University science and technology on water jet propulsion laboratory

In this paper, we investigate the verification and validation（V＆V） procedures for the URANS simulations of the turbulent cavitating flow around a Clark-Y hydrofoil. The main focus is on the feasibility of various Richardson extrapolation-based uncertainty estimators in the cavitating flow simulation. The unsteady cavitating flow is simulated by a density corrected model（DCM） coupled with the Zwart cavitation model. The estimated uncertainty is used to evaluate the applicability of various uncertainty estimation methods for the cavitating flow simulation. It is shown that the preferred uncertainty estimators include the modified Factor of Safety（FS1）, the Factor of Safety（FS） and the Grid Convergence Index（GCI）. The distribution of the area without achieving the validation at the U v level shows a strong relationship with the cavitation. Further analysis indicates that the predicted velocity distributions, the transient cavitation patterns and the effects of the vortex stretching are highly influenced by the mesh resolution.

关键词： Cavitating flow cavitation verification and validation(V&V) uncertainty

Numerical investigation of unsteady cavitating turbulent flows around twisted hydrofoil from the Lagrangian viewpoint

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Journal of Hydrodynamics 2016年第4期28卷 709-712页

作者：程怀玉龙新平季斌祝叶周加建 Wuhan University Hubei Key laboratory of waterjet Theory and New technology Wuhan University science and technology on water jet propulsion laboratory

Unsteady cavitating turbulent flow around twisted hydrofoil is simulated with Zwart cavitation model combined with the filter-based density correction model（FBDCM）.Numerical results simulated the entire process of the 3-D cavitation shedding including the re-entrant jet and side-entrant jet dynamics and were compared with the available experimental *** distribution of finite-time Lyapunov exponent（FTLE） was used to analyze the 3-D behavior of the re-entrant jet from the Lagrangian viewpoint,which shows that it can significantly influence the particle trackers in the attached *** analysis indicates that the different flow behavior on the suction side with different attack angle can be identified with Lagrangian coherent structures（LCS）.For the area with a large attack angle,the primary shedding modifies the flow pattern on the suction *** the decrease in attack angle,the attached cavity tends to be steady,and LCS A is close to the upper wall.A further decrease in attack angle eliminates LCS A in the boundary *** FTLE distribution also indicates that the decreasing attack angle induces a thinner boundary layer along the foil surface on the suction side.

关键词： viewpoint twisted correction Lagrangian suction unsteady attached coherent exponent turbulent

Spatial and spectral investigation of turbulent kinetic energy in cavitating flow generated by Clark-Y hydrofoil

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Journal of Hydrodynamics 2020年第1期32卷 175-178页

作者： Xiao-rui Bai Huai-yu Cheng Bin Ji Xin-ping Long State Key laboratory of water Resources and Hydropower Engineering science Wuhan UniversityWuhan 430072China science and technology on water jet propulsion laboratory Shanghai 200011China

In the present paper,the turbulent cavitating flow generated by a Clark-Y hydrofoil is investigated by large eddy simulation(LES)combined with Zwart-Gerber-Belamri(ZGB)cavitation *** order to shed light on the influence of cavitation on turbulent energy distribution among scales,energy spectrum obtained from the three-dimensional velocity field is firstly applied to turbulent cavitating *** and spectral distributions of turbulent kinetic energy are studied for both non-cavitating flow and cavitating *** is found to have a significant effect on the original turbulent flow by inducing more large-scale turbulent *** energy spectrum of cloud cavitating flow also experiences a periodic evolution as cavitation develops,and a large amount of turbulent kinetic energy is found to generate as the first shedding,cutoff and second shedding of cavities happen.

关键词： Cavitating flow energy spectrum large eddy simulation(LES) turbulent kinetic energy cloud cavitation

Risk assessment of erosive aggressiveness due to the condensation shock by numerical simulation

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Journal of Hydrodynamics 2022年第2期34卷 200-206页

作者： Wei Zhang Bing Zhu science and technology on water jet propulsion laboratory Marine Design and Research Institute of ChinaShanghai200011China School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai200093China

Cavitation is,for the engineering areas such as fluid machinery and ship propulsion,a known source of *** erosion damage due to cavitation bubble collapse can lead to extreme failure events,implying the replacement of a ship propeller or a turbine in a hydropower plant,all of which are very costly *** dynamics of cavitation hydraulic structure is of great importance for cavitation *** a result,the blade surface endures some extremely high stresses,which lead to the cause of *** major mechanisms,re-entrant jet as well as condensation shock,are known to such transient cavitating *** the present work we study the latter since less has been reported for the erosion caused by such an unsteady cavitating *** adopted an energy transportation equation based method,combined with a collapse event detection strategy,to carry out numerical erosion risk assessment for erosive aggressiveness due to the condensation *** with the paint test,our result shows good agreement in the erosive *** further discussed the hydrodynamics of the related flow structures.

关键词： Condensation shock numerical simulation cavitation erosion

Investigation on Maneuverability of a Twin-Screw Ship Driven by One Screw

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Journal of Shanghai Jiaotong university(science) 2017年第4期22卷 434-439页

作者：刘小健范佘明 National Key laboratory of science and technology on water jet propulsion Marine Design and Research Institute of ChinaShanghai 200011China

It is possible for a twin-screw ship that one screw failure occurs during navigation, and the maneuverability in this case should be noticed by ship designers and operators. It is of great significance to evaluate the related risk. Firstly, a mathematical model for the twin-screw ship maneuvering motion with one failed screw is developed based on the maneuvering model group (MMG) equations, and verified by the model test results. Secondly, the maneuvering motions of a twin-screw liquefied natural gas (LNG) ship with one free rotating failure screw or with one locked failure screw are simulated and compared by using the mathematical model. It is shown that the numerical modeling results are in agreement with the model test results. Compared with those of normal navigation, the port turning ability of the ship with one failed port screw is better, but the starboard turning ability and yaw checking ability become worse. The maneuverability of the ship with locked failure screw is better than that with free failure screw, although the ship speed drops obviously. © 2017, Shanghai Jiaotong University and Springer-Verlag GmbH Germany.

关键词： twin-screw ship screw failure maneuverability maneuvering model group(MMG) equation

Large eddy simulation of turbulent attached cavitating flow with special emphasis on large scale structures of the hydrofoil wake and turbulence-cavita-tion interactions

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Journal of Hydrodynamics 2017年第1期29卷 27-39页

作者：季斌龙云龙新平钱忠东周加建 State Key laboratory of water Resources and Hydropower Engineering science School of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China Hubei Key laboratory of waterjet Theory and New technology Wuhan UniversityWuhan 430072China science and technology on water jet propulsion laboratory Shanghai 200011China

In this paper, the turbulent attached cavitating flow around a Clark-Y hydrofoil is investigated by the large eddy simula- tion （LES） method coupled with a homogeneous cavitation model. The predicted lift coefficient and the cavity volume show a distinctly quasi-periodic process with cavitation shedding and the results agree fairly well with the available experimental data. The present simulation accurately captures the main features of the unsteady cavitation transient behavior including the attached cavity growth, the sheet/cloud cavitation transition and the cloud cavitation collapse. The vortex shedding structure from a hydrofoil cavitating wake is identified by the Q- criterion, which implies that the large scale structures might slide and roll down along the suction side of the hydrofoil while being further developed at the downstream. Further analysis demonstrates that the turbulence level of the flow is clearly related to the cavitation and the turbulence velocity fluctuation is much influenced by the cavity shedding.

关键词： Cavitation large eddy simulation (LES) vortex structure turbulence-cavitation interactions

URANS simulations of the tip-leakage cavitating flow with verification and validation procedures

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Journal of Hydrodynamics 2018年第3期30卷 531-534页

作者： Huai-yu Cheng Xin-ping Long Yun-zhi Liang Yun Long Bin Ji State Key laboratory of water Resources and Hydropower Engineering science School of Power and Mechanical EngineeringWuhan UniversityWuhan 430072China Hubei Key laboratory of waterjet Theory and New technology Wuhan UniversityWuhan 430072China science and technology on water jet propulsion laboratory Shanghai 200011China

In the present paper, the Vortex Identified Zwart-Gerber-Belamri（VIZGB） cavitation model coupled with the SST-CC turbulence model is used to investigate the unsteady tip-leakage cavitating flow induced by a NACA0009 hydrofoil. A qualitative comparison between the numerical and experimental results is made. In order to quantitatively evaluate the reliability of the numerical data, the verification and validation（V＆V） procedures are used in the present paper. Errors of numerical results are estimated with seven error estimators based on the Richardson extrapolation method. It is shown that though a strict validation cannot be achieved, a reasonable prediction of the gross characteristics of the tip-leakage cavitating flow can be obtained. Based on the numerical results, the influence of the cavitation on the tip-leakage vortex（TLV） is discussed, which indicates that the cavitation accelerates the fusion of the TLV and the tip-separation vortex（TSV）. Moreover, the trajectory of the TLV, when the cavitation occurs, is close to the side wall.

关键词： Cavitation computational fluid dynamics(CFD) tip-leakage vortex(TLV) verification and validation(V&V)

Numerical simulation on a film-cooled rotating model with 30° injection holes

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航空动力学报 2010年第7期25卷 1443-1453页

作者： YANG Bin XU Guo-qiang TAO Zhi DING Shui-ting WU Hong-wei National Key laboratory of science and technology on Aero-Engines School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

The flow and heat transfer characteristics were numerically investigated on a film cooling model under different rotating operating *** computational model was originated from the mid-span section of a typical turbine rotor with two rows of 14 staggered injection holes angled 30° both on the suction surface and pressure surface,and the flow through the coolant plenum and all the hole-pipes were resolved as a part of the computational domain by specifying the coolant mass flux in the *** computations primarily focus on under-standing the rotational effect on film cooling performance in mechanism research *** the present study,the Reynolds number(Re) based on mainstream velocity and injection hole diameter varied from 1835.5 to 5507.4,and the averaged blowing ratio(M) ranges of 0.5 to *** show that the coolant will move on to the high-radius locations near the suction and pressure surfaces due to the strong centrifugal effect,which leads to the decrease in adiabatic effectiveness *** discharge coefficients(Cd),on the pressure surface,are much higher than that on the suction surface under a given operating *** addition,the critical values of angular speed which represent the equilibrium of centrifugal force and Coriolis force near the pressure surface are also presented.

关键词： film cooling rotating adiabatic effectiveness heat transfer discharge coefficient

Review of the applications of Multiangle Imaging SpectroRadiometer to air quality research

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science China Earth sciences 2009年第1期52卷 132-144页

作者： Ralph A.KAHN jet propulsion laboratory California Institute of TechnologyPasadenaCA 91109USA

The Multiangle Imaging SpectroRadiometer(MISR) launched by NASA in late 1999 has a unique mul-tiangle design,which points nine cameras at fixed angles along the satellite flight track and collects reflected solar radiation *** design allows the retrieval of a rich dataset of particle abundance,shape and composition over both land and *** of its capabilities have not been seen by any currently operating satellite aerosol *** MISR is sensitive to fine particles,it provides a new data source to study the spatial and temporal characteristics of air quality over large geographical *** first briefly introduce the MISR instrument,the retrieval and structure of MISR aerosol data,and then review the applications of MISR aerosol data in various aspects of air quality research since its *** include the spatial distributions of particle pollution events such as dust storms,wild fires,and urban *** of the high quality of MISR aerosol data,they can be used as quantitative indicators of particle pollution *** review the current modeling studies of surface level particle ***,we introduce research results using MISR's advanced data such as the plume heights,and particle microphysical *** the discussion,we compare MISR research with current MODIS research to the best of our ability as MODIS data have been more extensively explored by the Chinese scientific ***,we summarize the advantages and disadvantages of MISR data related to its applications to the air quality *** the highly quantitative measurements and comprehensive aerosol information MISR can provide,we believe that it will provide great values to advance our understanding of the particle air pollution in China.

关键词： aerosol remote sensing MISR multiangle imaging aerosol optical thickness particulate matters PM2.5 PM10 air pollution