scholarly journals Three-dimensional temperature measurement around heating thin wire by background schlieren method

2007 ◽  
Vol 27 (Supplement1) ◽  
pp. 239-240
Author(s):  
Gen SATO ◽  
Nobuyuki FUJISAWA ◽  
Koji NAKASHIMA ◽  
Satoshi AIURA ◽  
Masakazu OKUBO
Keyword(s):  
Temperature Measurement ◽  
Three Dimensional ◽  
Thin Wire ◽  
Schlieren Method

scholarly journals In-Situ Local Temperature Measurement During Three-Dimensional Direct Laser Writing

CLEO: 2013 ◽  
2013 ◽  
Author(s):  
Jonathan Mueller ◽  
Joachim Fischer ◽  
Yatin Jadavji Mange ◽  
Thomas Nann ◽  
Martin Wegener
Keyword(s):  
Temperature Measurement ◽  
Three Dimensional ◽  
Local Temperature ◽  
Direct Laser Writing ◽  
Laser Writing ◽  
Direct Laser

Uncertainty Evaluation of the Rod Withdrawal at Power Accident Analysis Including 3D Neutron Kinetics

2012 ◽  
Author(s):  
Tomislav Bajs ◽  
Alessandro Petruzzi ◽  
Davor Grgić
Keyword(s):  
Temperature Measurement ◽  
Temperature Rise ◽  
Power Level ◽  
Three Dimensional ◽  
Nucleate Boiling ◽  
Coolant Temperature ◽  
System Response ◽  
Safety Margins ◽  
Control Assembly ◽  
System Variables

A continuous uncontrolled Rod Cluster Control Assembly (RCCA) bank withdrawal at power belongs to group of Reactivity Initiated Accidents (RIA). It will cause an increase in core heat flux and a reactor coolant temperature rise. Unless terminated by manual or automatic action, the power mismatch and resultant coolant temperature rise could eventually result in departure from nucleate boiling (DNB) and/or fuel centreline melt. The accident can be DNBR or overpower limiting accident depending on initial power level and rate and amount of reactivity addition. The Rod Withdrawal At Power (RWAP) accident was analyzed for NPP Krško to evaluate possible Resistance Temperature Detectors (RTD) bypass removal and introduction of thermowell for the average temperature measurement. The influence of different coolant temperature measurement delays to related protection system response and limiting system variables was studied first using point kinetics model as implemented in RELAP5 code. The selected scenario (maximum insertion rate with rods in manual mode) has been re-calculated using RELAP5/PARCS coupled code. Core wide departure from nucleate boiling ratio (DNBR) calculation has been performed at the end of the coupled code calculation using COBRA based model to determine minimum DNBR for hot channel. In order to assess available safety margins following such accident CIAU methodology has been applied to evaluate the uncertainty of RELAP5 analysis and modified CIAU/TN methodology to evaluate uncertainty of the three-dimensional neutronics/thermal-hydraulics calculations. Differences between system and coupled code results and uncertainties is discussed.

Reconstruction of the Flow Cross-Section Temperature Based on the Radiation Balance Between Infinitesimal

2011 ◽  
Vol 216 ◽  
pp. 238-243 ◽  
Author(s):  
R. Liu ◽  
X. Wan ◽  
Z.M. Zhang ◽  
W.H. Xiao
Keyword(s):  
Temperature Measurement ◽  
Cross Section ◽  
Three Dimensional ◽  
Emission Spectra ◽  
Test System ◽  
Difficult Problem ◽  
Radiation Balance ◽  
Flow Cross Section ◽  
Reconstructed Temperature ◽  
Flow Cross

The reconstruction of three-dimensional temperature field is a difficult problem. But three-dimensional temperature measurement can be simplified by the reconstruction of the flow cross-section temperature. In this paper, a theory of reconstruction is proposed and a simulation test system is implemented by MATLAB based on emission spectra tomography (EST) and radiation temperature measurement, which also take the emission and absorption characteristics in the processing of radiative transfer under consideration. Finally, by analyzing the difference of the original temperature and reconstructed temperature we can get the accuracy of the reconstruction theory.

Distortion in Thermal Field Around Inserted Thermocouples in Experimental Interfacial Studies, Part 4: End Effect

2000 ◽  
Vol 124 (1) ◽  
pp. 135-145 ◽  
Author(s):  
M. H. Attia ◽  
A. Cameron ◽  
L. Kops
Keyword(s):  
Finite Element ◽  
Measurement Error ◽  
Temperature Measurement ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Solid Material ◽  
Filler Material ◽  
Sensing Element ◽  
Element Analysis ◽  
Parametric Finite Element Analysis

The main objective of this investigation is to develop a model for predicting the systematic temperature measurement error due to the thermal disturbance in the region surrounding the thermocouple hot junction. A parametric finite element analysis has been conducted to model the general case of a three-dimensional thermocouple installation inserted in a blind hole. The variables considered in this study are the level of the heat flux in the measurement zone, as well as the thermal characteristics of the thermocouple wires, the filler material (cement), and the solid material in which the installation is placed. Analysis of the results showed that the pattern of the disturbed temperature field around the thermocouple sensing element is critically dependent on the ratio between the thermal conductivities of the filler material and the solid material. The results also showed that a reduction in the temperature gradient in the undisturbed field results in a considerable increase in the partial heat flow into the thermocouple wires, and consequently a significant systematic temperature measurement error. The effect of the eccentric positioning of the thermocouple on the uncertainty limits of the measurement error was found to be quite significant. A generalized model is presented to estimate the measurement error for any combination of the thermocouple installation attributes. Experimental verification of some aspects of this analysis has been carried out using a well-controlled experiment in which the thermocouple hole is scale-modelled. Comparison of the test results with the finite element predictions confirmed the accuracy and validity of the numerical modelling and results.

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