Experimental Analysis of Orifice Type Thrust Bearing

2006 ◽  
Author(s):  
Charanjeet Kaur Malhi ◽  
Trupti Cherian
Keyword(s):  
Measurement System ◽  
Experimental Analysis ◽  
Thrust Bearing ◽  
Three Dimensional ◽  
Air Bearing ◽  
Frame Design ◽  
Good Repeatability ◽  
Different Diameters ◽  
Good Agreement ◽  
Made In

A single pad thrust bearing with central orifice restrictor, was fabricated and tested with a loading frame design for varying loads and supply pressures. One of the objectives of conducting the test was to obtain load verses air-gap curves for different supply pressures. The air bearing was supplied with different diameters of orifice. Another objective was to measure recess pressure at different supply pressures and loads and obtain a three dimensional plot. The recess pressure in the bearing is measured by the Smart Pressure Device. The testing of the thrust bearing enabled to validate the measurement system used. The results obtained were in good agreement with the investigations made in this field by other investigators. The sensor used also showed good repeatability and linearity, which approves its use for the measurement system.

scholarly journals In-Depth Verification of a Numerical Model for an Axisymmetric RC Dome

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2152
Author(s):  
Przemysław Czumaj ◽  
Sławomir Dudziak ◽  
Zbigniew Kacprzyk
Keyword(s):  
Three Dimensional ◽  
Spatial Models ◽  
Detailed Comparison ◽  
The Finite Element Method ◽  
Robot System ◽  
Engineering Structures ◽  
Computational Analyses ◽  
Computational Systems ◽  
Good Agreement ◽  
Made In

The designers of civil engineering structures often have to face the problem of the reliability of complex computational analyses performed most often with the Finite Element Method (FEM). Any assessment of reliability of such analyses is difficult and can only be approximate. The present paper puts forward a new method of verification and validation of the structural analyses upon an illustrative example of a dome strengthened by circumferential ribs along the upper and lower edges. Four computational systems were used, namely Abaqus, Autodesk Robot, Dlubal RFEM, and FEAS. Different models were also analyzed—two-dimensional (2D) and three-dimensional (3D) ones using continuum, bar, and shell finite elements. The results of the static (with two kinds of load—self-weight and load distributed along the upper ring) and modal analyses are presented. A detailed comparison between the systems’ and models’ predictions was made. In general, the spatial models predicted a less stiff behavior of the analyzed dome than the planar models. The good agreement between different models and systems was obtained for the first natural frequency with axisymmetric eigenmodes (except from the Autodesk Robot system). The presented approach to the verification of complex shell–bar models can be effectively applied by structural designers.

The Experimental Study and Numerical Simulation of Turbulent Flow in Pumping Forebay

2009 ◽  
Author(s):  
Chao Liu ◽  
Jiren Zhou ◽  
Li Cheng
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Turbulent Flow ◽  
Three Dimensional ◽  
Computational Results ◽  
Experiment Study ◽  
Study Results ◽  
Measurement Results ◽  
Good Agreement ◽  
Made In

The experiment study was made to optimize the design of a pumping forebay. The Combined-sills were made in the forebay to eliminate the circulation and vortices of the diffusing flow successfully. The Numerical simulation of three-dimensional turbulent flow is applied on the complicate fore-and-aft flow of sills. The computational results are compared with the measurement results of physical model. The calculated results are in good agreement with the experimental data. The flow pattern is obviously improved. The study results have been applied in the project which gives a uniform approach flow to the pumping sump.

Sphericity Measurement Using Stitching Interferometry

2012 ◽  
Vol 523-524 ◽  
pp. 883-888 ◽  
Author(s):  
Takeshi Hagino ◽  
Yuichiro Yokoyama ◽  
Yutaka Kuriyama ◽  
Han Haitjema
Keyword(s):  
Standard Deviation ◽  
High Precision ◽  
Measurement System ◽  
Three Dimensional ◽  
Measuring Method ◽  
Surface Areas ◽  
Reference Sphere ◽  
Five Axes ◽  
Roundness Measurement ◽  
Good Agreement

A newly developed practical sphericity measurement system by means of stitching interferometry is described in this paper. Spheres are widely used in industry. In particular, spheres with stem are usually used in metrological applications such as reference sphere for Coordinate Measuring Machines. It is common to calibrate form of spheres with tactile roundness measurement, however a comprehensive form measurement is desired for evolving high precision applications. The developed system consists of commercial base Fizeau type interferometer to capture partial surface areas of sphere and five axes stages to handle sphere with stem. Hence the system is very suitable for measurement of such stemmed spheres. This system yields three dimensional form maps of stitched sphere and peak to valley sphericity. Standard deviation of sphericity value yielded using this system is less than 5 nm in 8 times repetition. Finally, an equatorial profile clipped from stitched sphere shows good agreement with a result of tactile roundness measuring method within 10 nm typically.

scholarly journals Design and Development of Two Manipulators as a Key Element of a Space Robot Testing Facility

2015 ◽  
Vol 62 (3) ◽  
pp. 377-394 ◽  
Author(s):  
Karol Seweryn ◽  
Kamil Grassmann ◽  
Konrad Rutkowski ◽  
Tomasz Rybus ◽  
Roman Wawrzaszek
Keyword(s):  
Control Systems ◽  
Measurement System ◽  
Three Dimensional ◽  
Control Algorithms ◽  
Air Bearing ◽  
Free Base ◽  
Torque Measurement ◽  
Test Bed ◽  
Space Manipulator ◽  
Testing Facility

Abstract The process of designing control systems for devices operating in microgravity, on-orbit environment, requires testing to verify the effectiveness and characteristics of the algorithms. The key issue is to design a relevant environment in terrestrial conditions that affects both the linear and angular three-dimensional motion of a rigid body. This paper contains a description of the mechanical aspects of two test beds used to evaluate control algorithms planned for use in a space manipulator. Two solutions are presented: (i) a planar manipulator with a free base placed on an air-bearing table; and (ii) a test bed with a 7-DOF manipulator fixed through a force-torque measurement system to the base.

A Three-dimensional Camera: Development and Applications of a Three-dimensional Image Measurement System

2011 ◽  
Vol 131 (2) ◽  
pp. 320-328 ◽  
Author(s):  
Cunwei Lu ◽  
Hiroya Kamitomo ◽  
Ke Sun ◽  
Kazuhiro Tsujino ◽  
Genki Cho
Keyword(s):  
Measurement System ◽  
Three Dimensional ◽  
Image Measurement ◽  
Dimensional Image

A Free Energy Perturbation Approach to Estimate the Intrinsic Solubilities of Drug-like Small Molecules

2019 ◽  
Author(s):  
Sayan Mondal ◽  
Gary Tresadern ◽  
Jeremy Greenwood ◽  
Byungchan Kim ◽  
Joe Kaus ◽  
...  
Keyword(s):  
Solid State ◽  
Small Molecules ◽  
Three Dimensional ◽  
Aqueous Solubility ◽  
Computational Approach ◽  
Free Energy Perturbation ◽  
Perturbation Approach ◽  
Energy Perturbation ◽  
State Form ◽  
Good Agreement

<p>Optimizing the solubility of small molecules is important in a wide variety of contexts, including in drug discovery where the optimization of aqueous solubility is often crucial to achieve oral bioavailability. In such a context, solubility optimization cannot be successfully pursued by indiscriminate increases in polarity, which would likely reduce permeability and potency. Moreover, increasing polarity may not even improve solubility itself in many cases, if it stabilizes the solid-state form. Here we present a novel physics-based approach to predict the solubility of small molecules, that takes into account three-dimensional solid-state characteristics in addition to polarity. The calculated solubilities are in good agreement with experimental solubilities taken both from the literature as well as from several active pharmaceutical discovery projects. This computational approach enables strategies to optimize solubility by disrupting the three-dimensional solid-state packing of novel chemical matter, illustrated here for an active medicinal chemistry campaign.</p>

An Experimental Analysis of Hydrostatic Thrust Bearing

2011 ◽  
Vol 81 (1-4) ◽  
pp. 95
Author(s):  
B. B. Roy ◽  
S. Pal ◽  
M. Bhattacharyya
Keyword(s):  
Experimental Analysis ◽  
Thrust Bearing

scholarly journals Simulation of Thermal and Electric Field Distribution in Packaged Sausages Heated in a Stationary Versus a Rotating Microwave Oven

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1622
Author(s):  
Wipawee Tepnatim ◽  
Witchuda Daud ◽  
Pitiya Kamonpatana
Keyword(s):  
Temperature Distribution ◽  
Electric Field ◽  
Three Dimensional ◽  
Development Stage ◽  
Microwave Oven ◽  
Computational Time ◽  
Plastic Package ◽  
Heating Uniformity ◽  
The Cost ◽  
Good Agreement

The microwave oven has become a standard appliance to reheat or cook meals in households and convenience stores. However, the main problem of microwave heating is the non-uniform temperature distribution, which may affect food quality and health safety. A three-dimensional mathematical model was developed to simulate the temperature distribution of four ready-to-eat sausages in a plastic package in a stationary versus a rotating microwave oven, and the model was validated experimentally. COMSOL software was applied to predict sausage temperatures at different orientations for the stationary microwave model, whereas COMSOL and COMSOL in combination with MATLAB software were used for a rotating microwave model. A sausage orientation at 135° with the waveguide was similar to that using the rotating microwave model regarding uniform thermal and electric field distributions. Both rotating models provided good agreement between the predicted and actual values and had greater precision than the stationary model. In addition, the computational time using COMSOL in combination with MATLAB was reduced by 60% compared to COMSOL alone. Consequently, the models could assist food producers and associations in designing packaging materials to prevent leakage of the packaging compound, developing new products and applications to improve product heating uniformity, and reducing the cost and time of the research and development stage.

scholarly journals 3D-Volume Rendering of the Pelvis with Emphasis on Paraurethral Structures Based on MRI Scans and Comparisons between 3D Slicer and OsiriX®

2021 ◽  
Vol 45 (3) ◽  
Author(s):  
C. M. Durnea ◽  
S. Siddiqi ◽  
D. Nazarian ◽  
G. Munneke ◽  
P. M. Sedgwick ◽  
...  
Keyword(s):  
Image Processing ◽  
Secondary Analysis ◽  
Three Dimensional ◽  
3D Models ◽  
Clinical Role ◽  
Cross Sectional ◽  
3D Slicer ◽  
Mri Scans ◽  
3D Volume ◽  
Good Agreement

AbstractThe feasibility of rendering three dimensional (3D) pelvic models of vaginal, urethral and paraurethral lesions from 2D MRI has been demonstrated previously. To quantitatively compare 3D models using two different image processing applications: 3D Slicer and OsiriX. Secondary analysis and processing of five MRI scan based image sets from female patients aged 29–43 years old with vaginal or paraurethral lesions. Cross sectional image sets were used to create 3D models of the pelvic structures with 3D Slicer and OsiriX image processing applications. The linear dimensions of the models created using the two different methods were compared using Bland-Altman plots. The comparisons demonstrated good agreement between measurements from the two applications. The two data sets obtained from different image processing methods demonstrated good agreement. Both 3D Slicer and OsiriX can be used interchangeably and produce almost similar results. The clinical role of this investigation modality remains to be further evaluated.

scholarly journals Experimental and Numerical Investigation about Small Clearance Journal Bearings under Static Load Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Carlo Alberto Niccolini Marmont Du Haut Champ ◽  
Fabrizio Stefani ◽  
Paolo Silvestri
Keyword(s):  
Three Dimensional ◽  
Journal Bearings ◽  
Radial Clearance ◽  
Small Scale ◽  
Test Rig ◽  
Small Clearance ◽  
Dimensional Simulation ◽  
Dynamic Loading Conditions ◽  
Static And Dynamic Loading ◽  
Good Agreement

The aim of the present research is to characterize both experimentally and numerically journal bearings with low radial clearances for rotors in small-scale applications (e.g., microgas turbines); their diameter is in the order of ten millimetres, leading to very small dimensional clearances when the typical relative ones (order of 1/1000) are employed; investigating this particular class of journal bearings under static and dynamic loading conditions represents something unexplored. To this goal, a suitable test rig was designed and the performance of its bearings was investigated under steady load. For the sake of comparison, numerical simulations of the lubrication were also performed by means of a simplified model. The original test rig adopted is a commercial rotor kit (RK), but substantial modifications were carried out in order to allow significant measurements. Indeed, the relative radial clearance of RK4 RK bearings is about 2/100, while it is around 1/1000 in industrial bearings. Therefore, the same original RK bearings are employed in this new test rig, but a new shaft was designed to reduce their original clearance. The new custom shaft allows to study bearing behaviour for different clearances, since it is equipped with interchangeable journals. Experimental data obtained by this test rig are then compared with further results of more sophisticated simulations. They were carried out by means of an in-house developed finite element (FEM) code, suitable for thermoelasto-hydrodynamic (TEHD) analysis of journal bearings both in static and dynamic conditions. In this paper, bearing static performances are studied to assess the reliability of the experimental journal location predictions by comparing them with the ones coming from already validated numerical codes. Such comparisons are presented both for large and small clearance bearings of original and modified RKs, respectively. Good agreement is found only for the modified RK equipped with small clearance bearings (relative radial clearance 8/1000), as expected. In comparison with two-dimensional lubrication analysis, three-dimensional simulation improves prediction of journal location and correlation with experimental results.

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