scholarly journals Modeling Boundary Conditions and Thermocouple Response in a Thermal Experiment

2006 ◽  
Author(s):  
Vicente J. Romero ◽  
Joe W. Shelton ◽  
Martin P. Sherman
Keyword(s):  
Heat Flux ◽  
Stainless Steel ◽  
Inverse Analysis ◽  
Element Model ◽  
Test Unit ◽  
Experimental Characterization ◽  
Thought Processes ◽  
Steel Cylinder ◽  
Epoxy Foam ◽  
Series Of Experiments

A series of experiments have been conducted in an effort to support the experimental characterization and modeling of a thermally decomposing foam. The hardware consists of a stainless steel cylinder (slug) embedded in a removable epoxy foam (REF). The slug/foam assembly is pressed into a 20-mil thick 3.5-inch diameter by 3.25-inch tall stainless steel can. In the particular experiment considered in this paper, the can was heated from the top by a bank of quartz heating lamps. In modeling the experiment, several non-trivial difficulties were encountered associated with characterization and modeling of the experimental heating conditions. In the paper we share some thought processes and describe the iterative modeling approach required to model the experiment. Novel features of the effort include modeling of embedded thermocouples in our finite-element model of the test unit, and inverse analysis to solve for the magnitude of incident heat flux from the quartz lamps.

Study on the Deformation of the Oil-Immersed Transformer Tank by FEA

2011 ◽  
Vol 422 ◽  
pp. 51-54 ◽  
Author(s):  
Jian Hua Zhang ◽  
Ling Yu Sun ◽  
Xiao Jun Zhang ◽  
Jia Peng Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Mechanical Strength ◽  
Element Model ◽  
3D Finite Element ◽  
3D Finite Element Model ◽  
Series Of Experiments ◽  
Oil Tank ◽  
Directive Function

The oil-immersed transformer tank is an outside package component of the transformer body. The sealing quality and mechanical strength of the oil tank are affected by the deformation after loading. In this paper, the 3D finite element model of oil-immersed transformer tank is established. The oil-immersed transformer tank deformation is obtained by FEA under the condition of vacuuming. A series of experiments about the deformation of the oil-immersed transformer tank are carried out. Comparing experiment results with FEA results, FEA results are agrees well with the experiments’. It can save the time consumed on designing the oil tank, and has the directive function for the whole design.

The Research on Grind Coefficient of Stainless Steel on Inverse Analysis for Prediction

2014 ◽  
Vol 988 ◽  
pp. 165-168
Author(s):  
Zhan Jun Liu
Keyword(s):  
Stainless Steel ◽  
Optimization Model ◽  
Inverse Analysis ◽  
Goal Function ◽  
Flow Chart ◽  
The Way

The theory and flow chart of inverse analysis arithmetic is based. The way of axile symmetry constringent and ring constringent test is introduced into optimization model and goal function , the goal is attained that inverse analysis of stainless steel is confirmed with grind and flowing vary coefficient, and that grind gene is confirmed with different plastic mock equipment. The result is proved that subdued stress of inverse analysis attained is treated as true subdued stress , the accuracy prediction of grind coefficient of ring constringent test on inverse analysis is obtained.

Experimental Characterization of a Flexible Two-Link Manipulator Arm

1993 ◽  
Author(s):  
Randall L. Mayes ◽  
G. Richard Eisler
Keyword(s):  
Element Model ◽  
Input Voltage ◽  
Analytical Models ◽  
Experimental Characterization ◽  
Frequency Range ◽  
Flexible Links ◽  
Beam Elements ◽  
Output Torque ◽  
Manipulator Arm

Abstract Experiments were performed to verify the analytical models for a robotic manipulator with two flexible links. A finite element model (FEM) employing two-dimensional beam elements was used to model the structure. A proportional model relating input voltage to output torque was used for both hub and elbow joint motors. With some minor adjustments to the link stiffness, the FEM modal frequencies matched the experimentally extracted frequencies within 1.5%. However the voltage-torque relationship for the hub motor was found to exhibit dynamics in the frequency range of interest.

Effects of Parameters on the Two-Phase Flow Instability in a Microchannel

2018 ◽  
Author(s):  
Yefei Liu ◽  
Yang Liu ◽  
Xingtuan Yang ◽  
Liqiang Pan
Keyword(s):  
Heat Flux ◽  
High Speed ◽  
Flow Instability ◽  
Working Fluid ◽  
Two Phase ◽  
Short Period ◽  
Period Oscillation ◽  
Data Acquisition Card ◽  
Series Of Experiments ◽  
Vertical Microchannel

Series of experiments are conducted in a single microchannel, where subcooled water flows upward inside a transparent and vertical microchannel. The cross section of the channel is rectangle with the hydraulic diameter of 2.8mm and the aspect ratio of 20. The working fluid is 3–15K subcooled and surface heat flux on the channel is between 0–3.64 kW/m2, among which two-phase instability at low vapor quantity may occur. By using a novel transparent heating technique and a high-speed camera, visualization results are obtained. The parameters are acquired with a National Instruments Data Acquisition card. In the experiments, long-period oscillation and short-period oscillation are observed as the primary types of instability in a microchannel. Instability characteristics represented from signals correspond well with the flow pattern. Moreover, effects of several parameters are investigated. The results indicate that the oscillating period generally increases with the heat flux density and decreases with inlet subcooling, while the effects of inlet resistance are more complex.

scholarly journals Experimental and Numerical Analysis on TIG Arc Welding of Stainless Steel Using RSM Approach

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1659
Author(s):  
Sasan Sattarpanah Karganroudi ◽  
Mahmoud Moradi ◽  
Milad Aghaee Attar ◽  
Seyed Alireza Rasouli ◽  
Majid Ghoreishi ◽  
...  
Keyword(s):  
Heat Flux ◽  
Stainless Steel ◽  
Welding Speed ◽  
Arc Welding ◽  
Welding Process ◽  
Weld Bead ◽  
Bead Geometry ◽  
Depth Of Penetration ◽  
Weld Bead Geometry ◽  
Bead Width

This study involves the validating of thermal analysis during TIG Arc welding of 1.4418 steel using finite element analyses (FEA) with experimental approaches. 3D heat transfer simulation of 1.4418 stainless steel TIG arc welding is implemented using ABAQUS software (6.14, ABAQUS Inc., Johnston, RI, USA), based on non-uniform Goldak’s Gaussian heat flux distribution, using additional DFLUX subroutine written in the FORTRAN (Formula Translation). The influences of the arc current and welding speed on the heat flux density, weld bead geometry, and temperature distribution at the transverse direction are analyzed by response surface methodology (RSM). Validating numerical simulation with experimental dimensions of weld bead geometry consists of width and depth of penetration with an average of 10% deviation has been performed. Results reveal that the suggested numerical model would be appropriate for the TIG arc welding process. According to the results, as the welding speed increases, the residence time of arc shortens correspondingly, bead width and depth of penetration decrease subsequently, whilst simultaneously, the current has the reverse effect. Finally, multi-objective optimization of the process is applied by Derringer’s desirability technique to achieve the proper weld. The optimum condition is obtained with 2.7 mm/s scanning speed and 120 A current to achieve full penetration weld with minimum fusion zone (FZ) and heat-affected zone (HAZ) width.

A Study of the Strain Response of Stainless Steel 304 to Extreme Uniform Instantaneous Explosion Pressure Loads

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Geraint O. Thomas ◽  
Gwyn L. Oakley
Keyword(s):  
Stainless Steel ◽  
Mechanical Response ◽  
Gaseous Detonation ◽  
Explosion Pressure ◽  
Mechanical Responses ◽  
Physical Measurements ◽  
Linear Relationships ◽  
Stainless Steel 304 ◽  
Series Of Experiments ◽  
Universal Correlation

Abstract The paper describes a new configuration using a gaseous detonation explosive blast source suitable for the studies of the instantaneous uniform pressure loading and mechanical response of materials. The capabilities of the configuration are illustrated by a preliminary series of experiments of the dynamic loading of clamped circular plates of 304 grade stainless steel with thicknesses ranging from 9.5 mm to 0.5 mm. The mechanical responses of the plates were monitored using strain gauges placed across the plate radius together with physical measurements of any permanent residual displacement of the center of the plate. The residual central deformations were analyzed using a well-established correlation involving nondimensional pressure load impulse. No universal correlation for the present data was found, but linear relationships for changes in two experimental parameters were identified, suggesting that the existing correlations have some deficiencies when applied to stainless steel 304.

A disc to air heat flux error and uncertainty analysis applied to a turbomachinery test rig design

2008 ◽  
Vol 223 (3) ◽  
pp. 659-674 ◽  
Author(s):  
A Cooke ◽  
P Childs ◽  
N Sayma ◽  
C A Long
Keyword(s):  
Heat Flux ◽  
Uncertainty Analysis ◽  
Inverse Analysis ◽  
Heat Fluxes ◽  
Bias Error ◽  
Test Rig ◽  
Care Needs ◽  
Disc Surface ◽  
Simulation Based ◽  
Study Heat Transfer

This article describes a Monte Carlo simulation-based error and an uncertainty analysis for values of disc to air heat fluxes as part of the design of an experimental axial turbine test rig. This work is of interest for those who study heat transfer and measurement or the design and use of experimental test rigs. An inverse analysis of theoretical disc surface temperatures was performed for different thermocouple configurations to compare the errors and uncertainties resulting from each to establish whether there was any configuration that would return the lowest magnitudes of error and uncertainty and hence influence the location of the proposed instrumentation. It is shown that great care needs to be taken when using an analysis of this kind together with temperature measurements having realistic and typical uncertainty values. This is because such an analysis is purely analytical, and any small fluctuations in the inputs, such as typical thermocouple uncertainties and noise, result in the process of an inverse analysis becoming unstable. This instability has two effects: (a) the returned values of heat flux have an inbuilt bias error and (b) the magnitudes of uncertainty can exceed>100 per cent.

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