scholarly journals 3D Temperature Distribution Reconstruction in Furnace Based on Acoustic Tomography

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Qian Kong ◽  
Genshan Jiang ◽  
Yuechao Liu ◽  
Jianhao Sun
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Hot Spot ◽  
Temperature Fields ◽  
Acoustic Tomography ◽  
Reconstruction Method ◽  
Distribution Models ◽  
Reconstructed Temperature ◽  
Value Decomposition ◽  
Radial Basis Function Approximation

3D temperature distribution measurement in a furnace based on acoustic tomography (AT) calculates temperature field through multipath acoustic time-of-flight (TOF) data. In this paper, a new 3D temperature field reconstruction model based on radial basis function approximation with polynomial reproduction (RBF-PR) is proposed for solving the AT inverse problem. In addition, the modified reconstruction method that integrates the advantages of the TSVD and Tikhonov regularization methods is presented to reduce the sensitivity of noise on perturbations with the ill-posed problems and improve the reconstruction quality (RQ). Numerical simulations are implemented to evaluate the effectiveness of the proposed reconstruction method using different 3D temperature distribution models, which include the one-peak symmetry distribution, one-peak asymmetry distribution, and two-peak symmetry distribution. To study the antinoise ability of our method, noises are added to the value of TOF. 3D display of reconstructed temperature fields and reconstruction errors is given. The results indicate that our model can reconstruct the temperature distribution with higher accuracy and better antinoise ability compared with the truncated generalized singular value decomposition (TGSVD). Besides that, the proposed method can determine the hot spot position with higher precision, and the temperature error of the hot spot is lower than the other compared methods.

scholarly journals A Method for Reconstruction of Boiler Combustion Temperature Field Based on Acoustic Tomography

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yuhui Wu ◽  
Xinzhi Zhou ◽  
Li Zhao ◽  
Chenlong Dong ◽  
Hailin Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Optimal Parameter ◽  
Interpolation Method ◽  
Least Square Method ◽  
Reconstruction Algorithm ◽  
Least Square ◽  
Temperature Fields ◽  
Acoustic Tomography ◽  
Measured Temperature

Acoustic tomography (AT), as a noninvasive temperature measurement method, can achieve temperature field measurement in harsh environments. In order to achieve the measurement of the temperature distribution in the furnace and improve the accuracy of AT reconstruction, a temperature field reconstruction algorithm based on the radial basis function (RBF) interpolation method optimized by the evaluation function (EF-RBFI for short) is proposed. Based on a small amount of temperature data obtained by the least square method (LSM), the RBF is used for interpolation. And, the functional relationship between the parameter of RBF and the root-mean-square (RMS) error of the reconstruction results is established in this paper, which serves as the objective function for the effect evaluation, so as to determine the optimal parameter of RBF. The detailed temperature description of the entire measured temperature field is finally established. Through the reconstruction of three different types of temperature fields provided by Dongfang Boiler Works, the results and error analysis show that the EF-RBFI algorithm can describe the temperature distribution information of the measured combustion area globally and is able to reconstruct the temperature field with high precision.

scholarly journals A New Algorithm for Reconstructing Two-Dimensional Temperature Distribution by Ultrasonic Thermometry

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xuehua Shen ◽  
Qingyu Xiong ◽  
Weiren Shi ◽  
Shan Liang ◽  
Xin Shi ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Ultrasound Velocity ◽  
Least Square Method ◽  
Reconstruction Algorithm ◽  
Industrial Applications ◽  
Least Square ◽  
Distribution Models ◽  
Practical Applications ◽  
Reconstruction Performance ◽  
Reconstructed Temperature

Temperature, especially temperature distribution, is one of the most fundamental and vital parameters for theoretical study and control of various industrial applications. In this paper, ultrasonic thermometry to reconstruct temperature distribution is investigated, referring to the dependence of ultrasound velocity on temperature. In practical applications of this ultrasonic technique, reconstruction algorithm based on least square method is commonly used. However, it has a limitation that the amount of divided blocks of measure area cannot exceed the amount of effective travel paths, which eventually leads to its inability to offer sufficient temperature information. To make up for this defect, an improved reconstruction algorithm based on least square method and multiquadric interpolation is presented. And then, its reconstruction performance is validated via numerical studies using four temperature distribution models with different complexity and is compared with that of algorithm based on least square method. Comparison and analysis indicate that the algorithm presented in this paper has more excellent reconstruction performance, as the reconstructed temperature distributions will not lose information near the edge of area while with small errors, and its mean reconstruction time is short enough that can meet the real-time demand.

scholarly journals Impact of Tunnel Temperature Variations on Surrounding Rocks in Cold Regions

2019 ◽  
Author(s):  
Qingyang Yu ◽  
Chao Zhang ◽  
Zhenxue Dai ◽  
Chao Du ◽  
Mohamad Reza Soltanian ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Insulation Layer ◽  
Cold Regions ◽  
Ambient Temperatures ◽  
Temperature Conditions ◽  
Layer Control

Temperature is an important factor in designing and maintaining tunnels, especially in cold regions. We present three-dimensional numerical simulations of tunnel temperature fields at different temperature conditions. We study the tunnel temperature field in two different conditions with relatively low and high ambient temperatures representing winter and summer of northeast China. We specifically study how these temperature conditions affect tunnel temperature and its migration to surrounding rocks. We show how placing an insulation layer could affect the temperature distribution within and around tunnels. Our results show that the temperature field without using an insulation layer is closer to the air temperature in the tunnel, and that the insulation layer has shielding effects and could plays an important role in preventing temperature migration to surrounding rocks. We further analyzed how thermal conductivity and thickness of insulation layer control the temperature distribution. The thermal conductivity and thickness of insulation layer only affect the temperature of the surrounding rocks which are located at distances below ~20 m from the lining.

Analysis of Plastic Strain Localization on the Basis of Strain and Temperature Fields / Analiza Lokalizacji Odkształcenia Plastycznego Na Podstawie Pola Odkształceń I Pola Temperatury

2012 ◽  
Vol 57 (4) ◽  
pp. 1111-1116 ◽  
Author(s):  
M. Maj ◽  
W. Oliferuk
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Plastic Strain ◽  
Strain Localization ◽  
Field Analysis ◽  
Temperature Fields ◽  
Uniform Temperature ◽  
Experimental Conditions ◽  
Plastic Strain Localization ◽  
Uniform Temperature Distribution

In the present paper the onset of plastic strain localization was determined using two independent methods based on strain and temperature field analysis. The strain field was obtained from markers displacement recorded using visible light camera. In the same time, on the other side of the specimen, the temperature field was determined by means of infrared camera. The objective of this work was to specify the conditions when the non-uniform temperature distribution can be properly used as the indicator of plastic strain localization. In order to attain the objective an analysis of strain and temperature fields for different deformation rates were performed. It has been shown, that for given experimental conditions, the displacement rate 2000 mm/min is a threshold, above which the non-uniform temperature distribution can be used as the indicator of plastic strain localization.

Research of the Temperature Field Distribution Based on FVM for Oil-Immersed Transformer

2014 ◽  
Vol 1079-1080 ◽  
pp. 510-514
Author(s):  
Yong Qiang Wang ◽  
Jie He ◽  
Lun Ma ◽  
Liu Wang ◽  
Ying Ying Sun ◽  
...  
Keyword(s):  
Temperature Field ◽  
High Temperature ◽  
Temperature Distribution ◽  
Field Distribution ◽  
Hot Spot ◽  
Load Capacity ◽  
Normal Operation ◽  
Internal Temperature ◽  
Temperature Field Distribution ◽  
Spot Temperature

Thehottest spot temperature (HST) of windings of oil-immersed transformer is animportant factor that affects load capacity and operation life of transformer,and is closely related to the transformer load, top oil and environmenttemperature. HST, when operating at high temperature and overload, may lead totransformer failure which will affect the normal operation of the power system.In order to calculate the transformer hot spot temperature accurately, we takea 33MVA-500KV transformer as an example, and establish a three dimensionalmodel, get its internal temperature distribution based on Fluent simulationsoftware. At last, we comparative and analysis the accuracy of FVM calculation andIEEE guidelines recommend model combined with online monitored values. Theresults show that the FVM method with higher accuracy relative to the IEEEguidelines model, proved that using the FVM can accurately calculate the HST ofoil-immersed transformer.

scholarly journals Study on Correlation Characteristics of Static and Dynamic Explosion Temperature Fields

2019 ◽  
Vol 2 (4) ◽  
pp. 6
Author(s):  
Liangquan Wang ◽  
Fei Shang ◽  
Deren Kong
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Functional Relationship ◽  
Temperature Fields ◽  
Temperature Correlation ◽  
Temperature Decay ◽  
Tnt Equivalent ◽  
Fitting Method ◽  
Field Temperature ◽  
The Relationship

The warheads such as missiles and artillery shells have a certain speed of motion during the explosion. Therefore, it is more practical to study the explosion damage of ammunition under motion. The different speeds of the projectiles have a certain influence on the temperature field generated by the explosion. In this paper, AUTODYN is used to simulate the process of projectile dynamic explosion. In the experiment, the TNT spherical bare charges with the TNT equivalent of 9.53kg and the projectile attack speed of 0,421,675,1020m/s were simulated in the infinite air domain. The temperature field temperature peaks and temperature decay laws at different charge rates and the multi-function regression fitting method were used to quantitatively study the functional relationship between the temperature and peak temperature correlation calculations of static and dynamic explosion temperature fields. The results show that the temperature distribution of the dynamic explosion temperature field is affected by the velocity of the charge, and the temperature distribution of the temperature field is different with the change of the charge velocity. Through the analysis and fitting of the simulation data, the temperature calculation formula of the static and dynamic explosion temperature field is obtained, which can better establish the relationship between the temperature peak of the static and dynamic explosion temperature field and various influencing factors, and use this function. Relational calculations can yield better results and meet the accuracy requirements of actual tests.

scholarly journals Temperature Distribution Monitoring Using Ultrasonic Thermometry Based on Markov Radial Basis Function Approximation and Singular Values Decomposition

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Xuehua Shen ◽  
Qingyu Xiong ◽  
Weiren Shi ◽  
Kai Wang ◽  
Guoqiang Lai
Keyword(s):  
Temperature Distribution ◽  
Radial Basis Function ◽  
Basis Function ◽  
Function Approximation ◽  
Singular Values ◽  
Ideal Gas ◽  
Distribution Models ◽  
Simulation Experiments ◽  
Radial Basis ◽  
Radial Basis Function Approximation

Information about temperature distribution is complex but of critical importance for the control of various microwave applications. In this paper, an innovative way of temperature distribution monitoring using ultrasonic thermometry in microwave field is investigated. The principle of ultrasonic thermometry in the situation of ideal gas is elaborated, and reconstruction algorithm based on Markov radial basis function approximation and singular values decomposition is presented and described in detail. In order to validate the performance of temperature distribution reconstruction of our presented algorithm, four two-dimensional temperature distribution models with different complexities are utilized in simulation experiments. Especially, simulation experiments taking error of measurement into account are studied to verify the robustness. Figure profiles show remarkable correspondence between the reconstructed ones and their models, while quantitative analysis, including the overall temperature error analysis and the hotspot positioning analysis, shows that different kinds of errors calculated are all within the limit ranges. In addition, the time analysis of simulation experiments also demonstrates its well real-time capability.

scholarly journals Dynamic thermal camouflage via a liquid-crystal-based radiative metasurface

Nanophotonics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 855-863 ◽  
Author(s):  
Yida Liu ◽  
Jinlin Song ◽  
Weixian Zhao ◽  
Xuecheng Ren ◽  
Qiang Cheng ◽  
...  
Keyword(s):  
Temperature Field ◽  
Liquid Crystal ◽  
Hot Spot ◽  
Orientation Angle ◽  
Infrared Camera ◽  
Electric Circuit ◽  
Temperature Fields ◽  
Angle Distribution ◽  
Stimuli Responsive ◽  
Rigorous Coupled Wave

AbstractThermal camouflage, which is used to conceal objects in the infrared vision for confrontation with infrared detection in civilian or military applications, has garnered increasing attraction and interest recently. Compared with conductive thermal camouflage, that is to tune heat conduction to achieve equivalent temperature fields, radiative thermal camouflage, based on emissivity engineering, is more promising and shows much superiority in the pursuit of dynamic camouflage technology when resorting to stimuli-responsive materials. In this paper, we demonstrate the emissivity-engineered radiative metasurface to realize dynamic thermal camouflage functionality via a flying laser heat source on the metal-liquid-crystal-metal (MLCM) platform. We employ a rigorous coupled-wave algorithm to calculate the surface emissivity of Au/LC/Au microstructures, where the LC-orientation angle distribution is quantified by minimizing the emitted thermal energy standard deviation throughout the whole plate. Emissivity engineering on the MCLM platform is attributed to multiple magnetic polariton resonance, and agrees well with the equivalent electric circuit analysis. Through this electrical modulation strategy, the moving hot spot in the original temperature field is erased and a uniform temperature field is observed in the infrared camera instead, demonstrating the very good dynamic thermal camouflage functionality. The present MLCM-based radiative metasurface may open avenues for high-resolution emissivity engineering to realize novel thermal functionality and develop new applications for thermal metamaterials and meta-devices.

Sign in / Sign up

Export Citation Format

Share Document