Experimental study of three-dimensional separation on a large-scale model

AIAA Journal ◽  
1995 ◽  
Vol 33 (11) ◽  
pp. 2107-2113 ◽  
Author(s):  
D. Barberis ◽  
P. Molton
Keyword(s):  
Experimental Study ◽  
Large Scale ◽  
Three Dimensional ◽  
Scale Model ◽  
Large Scale Model

scholarly journals Stability Improvement Method for Embankment Dam with Respect to Conduit Cracks

2022 ◽  
Vol 12 (2) ◽  
pp. 567
Author(s):  
Young-Hak Lee ◽  
Jung-Hyun Ryu ◽  
Joon Heo ◽  
Jae-Woong Shim ◽  
Dal-Won Lee
Keyword(s):  
Large Scale ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Internal Erosion ◽  
Scale Model ◽  
Seepage Analysis ◽  
Large Scale Model ◽  
Proposed Model ◽  
Improvement Method

In recent years, as the number of reservoir embankments constructed has increased, embankment failures due to cracks in aging conduits have also increased. In this study, a crack in a conduit was modeled based on the current conduit design model, and the risk of internal erosion was analyzed using a large-scale model test and three-dimensional deformation–seepage analysis. The results show that when cracks existed in the conduit, soil erosion and cavitation occurred near the crack area, which made the conduit extremely vulnerable to internal erosion. Herein, a model is proposed that can reduce internal erosion by applying a layer of sand and geotextiles on the upper part of the conduit located close to the downstream slope. In the proposed model, only partial erosion occurred inside the conduit, and no cavitation appeared near the crack in the conduit. The results suggest that internal erosion can be suppressed when the water pressure acting intensively on the crack in the conduit is dispersed by the drainage layer. To validate these results, the pore water pressure, seepage line, and hydraulic gradient were investigated to confirm the erosion phenomenon and reinforcement effect.

scholarly journals Studies on Three-Dimensional (3D) Modeling of UAV Oblique Imagery with the Aid of Loop-Shooting

2018 ◽  
Vol 7 (9) ◽  
pp. 356 ◽  
Author(s):  
Jia Li ◽  
Yongxiang Yao ◽  
Ping Duan ◽  
Yun Chen ◽  
Shuang Li ◽  
...  
Keyword(s):  
3D Modeling ◽  
Large Scale ◽  
3D Model ◽  
Three Dimensional ◽  
Scale Model ◽  
Scene Modeling ◽  
Standard Scale ◽  
Large Scale Model ◽  
City Construction ◽  
Key Steps

Oblique imagery obtained from an Unmanned Aerial Vehicle (UAV) has been widely applied to large-scale three-dimensional (3D) reconstruction; however, the problems of partially missing model details caused by such factors as occlusion, distortion, and airflow, are still not well resolved. In this paper, a loop-shooting-aided technology is used to solve the problem of details loss in the 3D model. The use of loop-shooting technology can effectively compensate for losses caused by occlusion, distortion, or airflow during UAV flight and enhance the 3D model details in large scene- modeling applications. Applying this technology involves two key steps. First, based on the 3D modeling construction process, the missing details of the modeling scene are found. Second, using loop-shooting image sets as the data source, incremental iterative fitting based on aerotriangulation theory is used to compensate for the missing details in the 3D model. The experimental data used in this paper were collected from Yunnan Normal University, Chenggong District, Kunming City, Yunnan Province, China. The experiments demonstrate that loop-shooting significantly improves the aerotriangulation accuracy and effectively compensates for defects during 3D large-scale model reconstruction. In standard-scale distance tests, the average relative accuracy of our modeling algorithm reached 99.87% and achieved good results. Therefore, this technique not only optimizes the model accuracy and ensures model integrity, but also simplifies the process of refining the 3D model. This study can be useful as a reference and as scientific guidance in large-scale stereo measurements, cultural heritage protection, and smart city construction.

A Large-Scale Model Developed for Predicting the Corroding Conditions of a Carrier Pipe in a Casing

2012 ◽  
Author(s):  
Fengmei Song ◽  
Andrew Nordquist
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Scale Model ◽  
Coating Quality ◽  
Metallic Contact ◽  
Internal Surfaces ◽  
Voltage Variation ◽  
Large Scale Model ◽  
Pipe Segment ◽  
Industry Needs

The corroding conditions of a cased carrier pipe segment are difficult to measure in the field. It is hard to know whether or how well the cased pipe segment is cathodically protected. The pipeline industry needs a tool that can predict the in-situ corrosion potential of the carrier pipe in the casing annulus in order to determine the level of cathodic protection (CP). This work reports on a large-scale, three-dimensional computer model developed to make such a prediction. The casing wall may be treated as bare or coated on both or either of the external and internal surfaces. The carrier pipe is coated, and the coating quality inside the annulus may or may not be the same as the outside of the casing segment. The casing annulus is full of electrolytes. The model is used to investigate the effect of several factors on the level of CP imposed on the carrier pipe in the annulus, including the coating quality on the carrier pipe, the casing wall native potentials (both external and internal), the presence of a coating on a casing wall surface, and a metallic contact (between the casing and the carrier pipe) with the contact resistance being a variable. The effect of the voltage variation inside the pipe metal wall is also investigated.

Reconciling Juno and past mission datasets to improve large-scale models of radiation-belt electron and radio emission distributions at Jupiter

2021 ◽  
Author(s):  
Daniel Santos-Costa ◽  
Frederic Allegrini ◽  
Rob Wilson ◽  
Peter Kollmann ◽  
George Clark ◽  
...  
Keyword(s):  
Radio Emission ◽  
Large Scale ◽  
Three Dimensional ◽  
Planck Equation ◽  
Radiation Belts ◽  
Scale Model ◽  
Data Sets ◽  
Electron Radiation ◽  
Large Scale Model ◽  
Electron Distributions

<p>We present our latest model of electron radiation belts developed for a large region of Jupiter's magnetosphere (1-50 Rj). For the region inward of Io, electron distributions are computed from a computational code that solves the governing three-dimensional Fokker-Planck equation. This physics-based model accounts for different mechanisms to discuss the energy and spatial distributions of electrons for L values between 1 and 5. The model for the innermost magnetospheric region is expanded to the middle magnetosphere using an empirical approach. In this paper, we first show how our large-scale model of Jupiter's electron radiation belts agrees with data sets from past missions (Pioneer 10 and 11 GTT, Galileo EPD and EPI measurements). We then focus on our effort to combine Juno (JEDI, JADE Electron Ambient Background Counts) and Galileo EPD (> 1.5, 11.5 MeV) datasets to improve our model for both the region beyond Io and the inner edge of the Jovian electron radiation belts. Finally, simulations of Jupiter's synchrotron emission are presented to gauge the contribution of ultra-energetic electrons trapped beyond L ~ 3 at different latitudes to radio emission observed by Juno MWR.</p>

scholarly journals Experimental study on dynamic interference effect of two closely spaced machine foundations

2016 ◽  
Vol 53 (2) ◽  
pp. 196-209 ◽  
Author(s):  
Abhijeet Swain ◽  
Priyanka Ghosh
Keyword(s):  
Experimental Study ◽  
Large Scale ◽  
Dynamic Condition ◽  
Dynamic Interaction ◽  
Scale Model ◽  
Harmonic Load ◽  
Machine Vibration ◽  
Large Scale Model ◽  
Local Soil ◽  
Wide Range

This paper presents an experimental study on the dynamic interaction effect of closely spaced square foundations under machine vibration. Under a dynamic condition, a number of large-scale model tests were conducted in the field, which includes a wide range of study on the isolated as well as interacting footing response resting on the local soil available at Kanpur, India. The dynamic interaction of different combinations (size) of two-footing assemblies was investigated by inducing vertical harmonic load on one of the footings (active footing), while the other footing (passive footing) was loaded with static weight only. The active footing was excited with different magnitudes of dynamic loading and the response was recorded for both footings, placed at a different clear spacing (S). The results are compiled and shown as the variation of displacement amplitude with frequency. The transmission ratio that predicts the effect of dynamic excitation of the active footing on the passive one is determined for the interacting footings and plotted with respect to frequency ratio.

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