Aero-optical wavefront measurement technique based on BOS and its applications

Tian, Lanlan; Yi, Shihe; Zhao, Yunfei; He, Lin; Chen, Zhi

doi:10.1007/s11434-011-4583-z

Cited by 19 publications

(4 citation statements)

References 14 publications

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“…Besides the multiple arch-cantilever method requested by the dam design codes, many modern numerical methods and tests are developed to obtain more realistic stresses and displacements for static [93][94][95][96][97][98] and dynamic [99][100][101][102][103][104] analysis of dam. With these methods and tests, the location and area as well as the extent of cracking, crushing and shear failure can be figured out.…”

Section: Safety Analysis Of Local Strength Failurementioning

confidence: 99%

Research advance in failure risk and local strength failure for high arch dams

Ren

Liu

2012

Chin. Sci. Bull.

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To develop national economy and use the water resources and hydropower resources sufficiently, a lot of high arch dams, with the height of more than 200 m, have been and will be built in China. Although arch dams have good mechanical behavior, there is still failure possibility due to the huge water pressure and high stress level in dam, complex topographic and geologic conditions, formidable environment and high intensity earthquake. As one of the three main aspects concerning the safety of high arch dam, the study on global destruction, has been elaborated in the literatures, and research advance in the other two aspects, namely the failure risk and local damage of high arch dams, will be reviewed in this paper. In recent years, the failure risk of high arch dams has been investigated, and the model for identifying dam failure risk factors has been established. It is shown that the foundation deterioration and strong earthquake are the major risk sources for high dam failure. With the fault tree method, the failure mode and failure probability of high arch dams are studied, and the principle for determining failure mode and the method of calculating failure probability are proposed. Meanwhile, the determination principle of acceptable risk standard for high arch dam was proposed, and the acceptable risk rate and the acceptable standard value of various risk losses were given. For the local damage of arch dam, it is pointed out that the local damage belongs to the strength failure at material level. The study on local failure mechanism of arch dam is reviewed, based on the theories that from traditional strength theory to damage mechanics and meso-mechanics theory. Aiming at the cracking, the main pattern of local failure of high concrete dam, the research advances in the analysis methods and cracking criteria for smeared crack model and discrete crack model are summarized, and the research findings of preventive measures for local failure are shown. high arch dam, failure risk, local damage, research advance Citation:Ren Q W, Li Q, Liu S. Research advance in failure risk and local strength failure for high arch dams. Chin Sci Bull, 2012Bull, , 57: 46724682, doi: 10.1007 To develop national economy, to save energy and to reduce emission, exploitation and utilization of water resources and hydropower resources are continued in China. At present, the height of arch dams under construction and to be built are of 300 m high level, such as Jinping arch dam (305 m high), Xiaowan arch dam (294.5 m high), Xiluodu arch dam (285.5 m high), and Baihetan arch dam (289 m high). The construction scale and difficulty of these dams are beyond the current design specifications, and there is hardly successful precedential reference. Moreover most of these high arch dams are located in the western region of China, where the topographic and geologic conditions are quite complex, with harsh environment and high seismic intensity as well as frequent geological disasters. In addition the resistance of dam and foundation may be red...

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Section: Safety Analysis Of Local Strength Failurementioning

confidence: 99%

Research advance in failure risk and local strength failure for high arch dams

Ren

Liu

2012

Chin. Sci. Bull.

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“…面开发了基于纳米粒子的平面激光散射技术(NPLS), [25] 、飞行器绕流、气动光学 [26,27] [29] , 可测得涡结构沿 x 方向的位移(7.4 mm, 8.3 mm 和 8.9 mm). 从下游特征涡结构在参考文献…”

Section: 近年来国防科学技术大学在超声速流场测试方unclassified

超声速半球绕流实验研究

王¹,

赵²,

王³

et al. 2012

Chin. Sci. Bull.

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“…The experimental system (NPLS) has been used in the research of supersonic mixing layer [21][22][23][24], boundary layer [25], flow over aircrafts and the aero-optical [26,27], and the numerous experimental data was obtained and had made some progress in the fields. In this paper, based on the characteristics of high resolution flow visualization of the NPLS system and combined with numerical simulation technology, the fine structures and evolutionary characteristics of supersonic flow over a hemisphere were made a deep study.…”

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confidence: 99%

Experimental investigation of supersonic flow over a hemisphere

et al. 2012

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The experimental investigation of supersonic flow over a hemisphere was conducted using Nanoparticle-based Planar Laser Scattering (NPLS) technique in a supersonic quiet wind tunnel at Ma=2.68. Ahead of the hemisphere, boundary layer separation with the formation of a three-dimensional separated flow was observed, which was resulted from the interaction between the three-dimensional bow shock wave and the boundary layer. The complex flow structures of supersonic flow over the hemisphere were visualized. Based on the time correlation of NPLS images, time-space evolutionary characteristics of supersonic flow over the hemisphere were studied, and the evolutionary characteristics of the spanwise and streamwise large scale vortex structures were obtained, which have the features of periodicity and similar geometry. The protuberance is mounted on the surface or flow channel of the supersonic or hypersonic vehicle and the local structure of the flow field will be changed. Currently, achieving flow control has been becoming a research hotspot of supersonic flow. The study of the supersonic plate boundary layer and its interaction with the hemisphere has broad application background and high scientific value. The mutual interference of the hemisphere and supersonic flow generates complex flow field structures, which contain the three-dimensional detached shock wave, the surface topological structure, the circulating region in the downstream, the reattached shock wave and the wake. The complex flow field structures show the characteristics of the supersonic flow over a protuberance on the surface. Therefore the hemisphere can be used as a typical model to study the mechanism of the supersonic flow over a protuberance on the surface, and is also used to verify some questions that are disputed at present, such as the interaction of the three-dimensional curved shock wave and the boundary layer, the effect of the lateral pressure gradient on the surface flow spectrums and the dynamic characteristics of the supersonic vortical structure. Unfortunately, the influences of strong discontinuity and diffusion factors, such as compressibility, turbulence, large scale structure, shock waves and slip line, make it difficult to get the fine structure of supersonic flow over a hemisphere by means of high resolution numerical simulation and measurement. Hawthorne and Martin [1] studied the flow over a hemisphere on the flat plate by means of calculation method in 1955. Zhang [2] studied the interaction of the shock wave and boundary layer about the external flow and internal flow, and provided the photos of typical flow spectrums of different experimental models, including the photos of supersonic flow over a sphere. Some research institutions have studied the typical flow field structures of the supersonic flow over different models by means of experimental and numerical methods at home and abroad, and the models included the cylinder [3][4][5][6][7][8][9][10][11][12][13], the boss [5,6], the blunt fin [5,12], the wedge-shaped obstacle...

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Aero-optical wavefront measurement technique based on BOS and its applications

Cited by 19 publications

References 14 publications

Research advance in failure risk and local strength failure for high arch dams

Research advance in failure risk and local strength failure for high arch dams

超声速半球绕流实验研究

Experimental investigation of supersonic flow over a hemisphere

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