Experimental Investigation of a Hydromechanical Scale Model of the Gerbil Cochlea

2008 ◽  
Author(s):  
Shuangqin Liu ◽  
Douglas A. Gauthier ◽  
Ethan Mandelup ◽  
Robert D. White
Keyword(s):  
Experimental Investigation ◽  
Characteristic Frequency ◽  
Basilar Membrane ◽  
Silicone Oil ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Scale Model ◽  
Wkb Method ◽  
Laser Vibrometry ◽  
The Real

In this research, an uncoiled scale gerbil cochlea is designed and fabricated. The cochlea model is an uncoiled, 16 times scale model of the real gerbil cochlea and has only one duct. Both the basilar membrane width and the duct size vary along the length of the device, in analogy to the physiology. The cochlea duct is filled with silicone oil and driven by a modal exciter (shaker) at different frequencies. The movement of the basilar membrane is measured using laser vibrometry at different locations along the basilar membrane. The ratio of the basilar membrane velocity to drive velocity is computed and plotted. The characteristic frequency of the model varies from 7000 Hz at 2 cm from the base of the cochlea to 350 Hz at the 15 cm from the base. Two different viscosities silicone oil, 20 cSt and 500 cSt are used for the basilar membrane movement measurements. A WKB method is applied to the calculation of the basilar membrane movement of the scale cochlea model, in which the fluid motion is fully three dimensional.

Anti-Slosh Effectiveness of Baffles and Braking Performance of a Partly-Filled Tank Truck

2014 ◽  
Vol 541-542 ◽  
pp. 674-683
Author(s):  
Fan Yang ◽  
G. Yan ◽  
S. Rakheja
Keyword(s):  
Fluid Dynamic ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Scale Model ◽  
Fluid Structure Interactions ◽  
Tank Truck ◽  
Plane Model ◽  
Braking Performance ◽  
Straight Line ◽  
Spectral Components

The liquid cargo movement within a partly-filled tank truck affects its braking, roll dynamics and directional performance in an adverse manner. In this study, the braking performance of a partly-filled tank truck equipped with different baffles designs is investigated considering dynamic fluid-structure interactions. The validity of the computational fluid dynamic model is examined through laboratory tests conducted on a scale model tank with and without baffles. The measured responses to harmonic excitations revealed three-dimensional nature of the fluid motion and couplings between the lateral and longitudinal fluid slosh. Several spectral components were observed for the transient slosh forces, which could be associated with the excitation, resonance, and beat frequencies. A dynamic pitch plane model of a Tridem truck incorporating three-dimensional fluid slosh dynamics is subsequently developed to analyze the fluid-vehicle interactions under straight-line braking maneuvers. The results show that the vehicle responses are highly influenced by the slosh-induced force and moment.

Development of Three-Dimensional Seismic Isolation Technology for Next Generation Nuclear Power Plant Applications

2005 ◽  
Author(s):  
K. Takahashi ◽  
K. Inoue ◽  
M. Morishita ◽  
T. Fujita
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Three Dimensional ◽  
Scale Model ◽  
Isolation System ◽  
The Real ◽  
Reactor Building

Seismic isolation technology plays an important role in the area of architect engineering, especially in Japan where earthquake comes so often. This technology also makes the nuclear power plant rationalized. The horizontal base isolation with laminated rubber bearings has already been proven its effectiveness. These days, seismic isolation technology is expected to mitigate even the vertical load, which affects the structural design of primary components. Seismic isolation system has possibility to improve the economical situation for the nuclear power plant. From these points of view, a research project has been proceeded to realize practical three dimensional seismic isolation systems from 2000 to 2005 under the sponsorship of the Ministry of Economy, Trade and Industry of the Japanese government. The isolation system is developed for the supposed “Fast Breeder Reactor (abbreviated FBR)” of the next generation. Two types of seismic isolation systems are developed in the R&D project. One is a three-dimensional base isolation for a reactor building (abbreviated 3D SIS) and the other is a vertical isolation for main components with horizontal base isolation of the reactor building (abbreviated V. +2D SIS). At first step of the R&D, requirements and targets of development for the seismic isolation system were identified. Seismic condition for R&D was discussed based on the real seismic response. Vertical natural frequency and damping ratio required to the system were introduced from the response to the seismic movement. As for 3D SIS, several system concepts were proposed to satisfy the requirements and targets. Through discussions and tests on performance, reliability, applicability, maintainability, “Rolling seal type air spring system with hydraulic anti-rocking devices” was decided to be developed. Verification shaking tests with the 1/7 scale model of the system and analysis for applicability to the real plant are conducted. The result shows that the system is able to support the reactor building, to suppress the rocking motion and to mitigate the vertical seismic load. As for V.+2D SIS, coned disk spring device was selected at the beginning of R&D. Performance tests of the elements, which include common deck movement, were conducted and the system applicability to the plant is confirmed. Verification tests were conducted with 1/8 scale model of the system and the result proves the applicability to the real plant.

Three-dimensional Reconstruction of Microscopic Image Based on Multi-ST Algorithm

2020 ◽  
Vol 64 (2) ◽  
pp. 20506-1-20506-7
Author(s):  
Min Zhu ◽  
Rongfu Zhang ◽  
Pei Ma ◽  
Xuedian Zhang ◽  
Qi Guo
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Scale Model ◽  
Microscopic Image ◽  
Multi Scale ◽  
Gaussian Pyramid ◽  
Cost Aggregation ◽  
Dimensional Reconstruction ◽  
Image Pairs ◽  
Accurate Matching

Abstract Three-dimensional (3D) reconstruction is extensively used in microscopic applications. Reducing excessive error points and achieving accurate matching of weak texture regions have been the classical challenges for 3D microscopic vision. A Multi-ST algorithm was proposed to improve matching accuracy. The process is performed in two main stages: scaled microscopic images and regularized cost aggregation. First, microscopic image pairs with different scales were extracted according to the Gaussian pyramid criterion. Second, a novel cost aggregation approach based on the regularized multi-scale model was implemented into all scales to obtain the final cost. To evaluate the performances of the proposed Multi-ST algorithm and compare different algorithms, seven groups of images from the Middlebury dataset and four groups of experimental images obtained by a binocular microscopic system were analyzed. Disparity maps and reconstruction maps generated by the proposed approach contained more information and fewer outliers or artifacts. Furthermore, 3D reconstruction of the plug gauges using the Multi-ST algorithm showed that the error was less than 0.025 mm.

Modeling and Assessment of the Produced Water Discharges from Offshore Petroleum Platforms

2007 ◽  
Vol 42 (4) ◽  
pp. 303-310 ◽  
Author(s):  
Zhi Chen ◽  
Lin Zhao ◽  
Kenneth Lee ◽  
Charles Hannath
Keyword(s):  
Random Walk ◽  
Produced Water ◽  
Model Development ◽  
Three Dimensional ◽  
Monitoring Program ◽  
Ecological Monitoring ◽  
Numerical Approach ◽  
Ocean Model ◽  
Scale Model ◽  
Water Stream

Abstract There has been a growing interest in assessing the risks to the marine environment from produced water discharges. This study describes the development of a numerical approach, POM-RW, based on an integration of the Princeton Ocean Model (POM) and a Random Walk (RW) simulation of pollutant transport. Specifically, the POM is employed to simulate local ocean currents. It provides three-dimensional hydrodynamic input to a Random Walk model focused on the dispersion of toxic components within the produced water stream on a regional spatial scale. Model development and field validation of the predicted current field and pollutant concentrations were conducted in conjunction with a water quality and ecological monitoring program for an offshore facility located on the Grand Banks of Canada. Results indicate that the POM-RW approach is useful to address environmental risks associated with the produced water discharges.

Numerical Study of the Mean and Filtered Characteristics of Turbulent Jets Impinging on Convex and Flat Surfaces Using LES

2012 ◽  
Author(s):  
Adra Benhacine ◽  
Zoubir Nemouchi ◽  
Lyes Khezzar ◽  
Nabil Kharoua
Keyword(s):  
Convex Surface ◽  
Numerical Study ◽  
Three Dimensional ◽  
Turbulent Jets ◽  
Scale Model ◽  
Wall Jet ◽  
Potential Core ◽  
Flat Surfaces ◽  
Free Jet ◽  
Eddy Simulation

A numerical study of a turbulent plane jet impinging on a convex surface and on a flat surface is presented, using the large eddy simulation approach and the Smagorinski-Lilly sub-grid-scale model. The effects of the wall curvature on the unsteady filtered, and the steady mean, parameters characterizing the dynamics of the wall jet are addressed in particular. In the free jet upstream of the impingement region, significant and fairly ordered velocity fluctuations, that are not turbulent in nature, are observed inside the potential core. Kelvin-Helmholtz instabilities in the shear layer between the jet and the surrounding air are detected in the form of wavy sheets of vorticity. Rolled up vortices are detached from these sheets in a more or less periodic manner, evolving into distorted three dimensional structures. Along the wall jet the Coanda effect causes a marked suction along the convex surface compared with the flat one. As a result, relatively important tangential velocities and a stretching of sporadic streamwise vortices are observed, leading to friction coefficient values on the curved wall higher than those on the flat wall.

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