scholarly journals Non-Uniform Temperature Field of Spatial Grid Structure under Construction Induced by Solar Radiation

2020 ◽  
Vol 10 (7) ◽  
pp. 2445
Author(s):  
Deshen Chen ◽  
Hongliang Qian ◽  
Huajie Wang ◽  
Wucheng Xu ◽  
Jingfang Li
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Test Data ◽  
Maximum Temperature ◽  
Uniform Temperature ◽  
Grid Structure ◽  
Spatial Grid ◽  
Under Construction

The temperature of spatial structures under construction can have a significant non-uniform distribution induced by intense solar radiation. This temperature distribution affects the component assembly and results in closure difficulties, potentially causing safety hazards. A spatial grid structure model was designed and subjected to temperature field test under sunlight to study the temperature distribution of the structure and for comparison with numerical simulation methods. The distribution characteristics and the time-varying laws were analyzed based on the test data. Then, the ray-casting algorithm was introduced to analyze the shadow influence between members, so that the temperature distribution of the model was simulated accurately, which was verified by the test data. The results show that the spatial grid structure had an obvious non-uniform temperature distribution, with a maximum temperature rise of 16 °C when compared with ambient temperature and a maximum temperature difference between members of 11 °C. The variation laws were gained both from the test and the numerical simulation. The numerical simulation method proposed herein can be used to calculate the shadow distribution and the temperature field of the structure effectively. The research methods and conclusions can provide valuable references for thermal design, monitoring, and control of spatial grid structures.

Non-uniform temperature distribution of the main reflector of a large radio telescope under solar radiation

2021 ◽  
Vol 21 (11) ◽  
pp. 293
Author(s):  
Shan-Xiang Wei ◽  
De-Qing Kong ◽  
Qi-Ming Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Radio Telescope ◽  
Thermal Imaging ◽  
Uniform Temperature ◽  
Large Radio Telescope ◽  
Uniform Temperature Distribution ◽  
Uniform Temperature Field ◽  
Main Reflector

Abstract The non-uniform temperature distribution of the main reflector of a large radio telescope may cause serious deformation of the main reflector, which will dramatically reduce the aperture efficiency of a radio telescope. To study the non-uniform temperature field of the main reflector of a large radio telescope, numerical calculations including thermal environment factors, the coefficients on convection and radiation, and the shadow boundary of the main reflector are first discussed. In addition, the shadow coverage and the non-uniform temperature field of the main reflector of a 70-m radio telescope under solar radiation are simulated by finite element analysis. The simulation results show that the temperature distribution of the main reflector under solar radiation is very uneven, and the maximum of the root mean square temperature is 12.3°C. To verify the simulation results, an optical camera and a thermal imaging camera are used to measure the shadow coverage and the non-uniform temperature distribution of the main reflector on a clear day. At the same time, some temperature sensors are used to measure the temperature at some points close to the main reflector on the backup structure. It has been verified that the simulation and measurement results of the shadow coverage on the main reflector are in good agreement, and the cosine similarity between the simulation and the measurement is above 90%. Despite the inevitable thermal imaging errors caused by large viewing angles, the simulated temperature field is similar to the measured temperature distribution of the main reflector to a large extent. The temperature trend measured at the test points on the backup structure close to the main reflector without direct solar radiation is consistent with the simulated temperature trend of the corresponding points on the main reflector with the solar radiation. It is credible to calculate the temperature field of the main reflector through the finite element method. This work can provide valuable references for studying the thermal deformation and the surface accuracy of the main reflector of a large radio telescope.

Numerical Simulation on Temperature Field of CFST Member under Solar Radiation

2011 ◽  
Vol 354-355 ◽  
pp. 1241-1244
Author(s):  
Yan He ◽  
Man Ding ◽  
Qian Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Cross Section ◽  
Temperature Difference ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Nonlinear Temperature ◽  
The Cross

In this paper the temperature field of Concrete Filled Steel Tube (CFST) member under solar radiation is simulated. The results show that temperature distribution caused by solar radiation is nonlinear over the cross-section of CFST member, and it is significantly varied with time and sections, the largest nonlinear temperature difference is over 26.3°C.

Study on Thermal Field of Mass Concrete by Experiment and Numerical Simulation

2010 ◽  
Vol 168-170 ◽  
pp. 1117-1121
Author(s):  
Xiao Yong Li ◽  
Zhi Gang Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Thermal Field ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Ansys Software ◽  
Field Development ◽  
Concrete Temperature ◽  
Age Dependent ◽  
Under Construction

An experimental study is conducted to simulate the thermal field in mass concrete. Accurate prediction of the thermal stress by analysis is quite difficult particularly at early ages, due to uncertain age-dependent properties of concrete. A series of tests was conducted in which the temperature was measured for a large number of observation points. The effect of aging and the amount of measuring points on thermal field development that can occur in realistic structures was evaluated. Numerical simulations of the thermal field setup were also performed using the finite element with ANSYS software to verify and extend the experimental interpretation and to determine the maximum temperature value which would occur under construction process. Mass concrete temperature field and stress field for specific projects were measured and analyzed. Numerical simulation of mass concrete temperature field for the actual project is compared with the measured results. The results show that the temperature field of numerical simulation results and measured curves result are of the same trend. And it is feasible that mass concrete temperature field is simulated based on ANSYS.

Numerical Simulation of Temperature Field in the Cyclone

2012 ◽  
Vol 614-615 ◽  
pp. 208-211
Author(s):  
Zhen Wei Zhang ◽  
Ying Yu ◽  
Jie Leng ◽  
Su Juan Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Turbulence Model ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Inlet Tube ◽  
Higher Temperature ◽  
Air Compression

The temperature distribution of the cyclone was analyzed in the presented work, which was imitated by using RSM turbulence model of software FLUENT. Temperature difference in different regions is less than one centigrade degree with the maximum temperature in the cone part and the minimum temperature in inlet tube and cylinder part of the cyclone, what’s more, the temperature is relatively higher near the wall. The air compression can lead the higher temperature in the lower part, so the cone part has the maximum temperature. The higher temperature near the wall is caused by the friction between the wall and flow.

Numerical Simulation of Temperature Field in the Cyclone

2012 ◽  
Vol 479-481 ◽  
pp. 462-466
Author(s):  
Ping Yang Xiao ◽  
Zhen Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Turbulence Model ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Inlet Tube ◽  
Higher Temperature ◽  
Air Compression

This paper mainly focuses on the numerical simulation of temperature field in the cyclone separation. The authors took advantage of RSM turbulence model of software FLUENT to imitate the temperature field. This thesis puts forward the temperature distribution of the cyclone, and figures out that the overall temperature is 373°C. Temperature difference in different region is less than one centigrade degree with the maximum temperature in the cone part and the minimum temperature in inlet tube and cylinder part of the cyclone, what’s more, the temperature is relatively higher near the wall. The air compression can lead the higher temperature in the lower part, so the cone part has the highest temperature. The higher temperature near the wall is caused by the friction between the wall and flow.

Experimental and numerical investigation of the thermomechanical load on a turbine housing in a radial turbocharger

2021 ◽  
pp. 095440702110521
Author(s):  
Shaolin Chen ◽  
Hong Zhang ◽  
Liaoping Hu ◽  
Guangqing He ◽  
Fen Lei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Fatigue Life ◽  
Simulation Analysis ◽  
Simulation Method ◽  
Testing Temperature ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Monitoring Point ◽  
Turbine Housing

The fatigue life of turbine housing is an important index to measure the reliability of a radial turbocharger. The increase in turbine inlet temperatures in the last few years has resulted in a decrease in the fatigue life of turbine housing. A simulation method and experimental verification are required to predict the life of a turbine housing in the early design and development process precisely. The temperature field distribution of the turbine housing is calculated using the steady-state bidirectional coupled conjugate heat transfer method. Next, the temperature field results are considered as the boundary for calculating the turbine housing temperature and thermomechanical strain, and then, the thermomechanical strain of the turbine housing is determined. Infrared and digital image correlations are used to measure the turbine housing surface temperature and total thermomechanical strain. Compared to the numerical solution, the maximum temperature RMS (Root Mean Square) error of the monitoring point in the monitoring area is only 3.5%; the maximum strain RMS error reached 11%. Experimental results of temperature field test and strain measurement test show that the testing temperature and total strain results are approximately equal to the solution of the numerical simulation. Based on the comparison between the numerical calculation and experimental results, the numerical simulation and test results were found to be in good agreement. The experimental and simulation results of this method can be used as the temperature and strain (stress) boundaries for subsequent thermomechanical fatigue (TMF) simulation analysis of the turbine housing.

Temperature distribution simulations during electron beam freeform fabrication process based on the fully threaded tree

2019 ◽  
Vol 25 (6) ◽  
pp. 989-997
Author(s):  
Yajun Yin ◽  
Wei Duan ◽  
Kai Wu ◽  
Yangdong Li ◽  
Jianxin Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Design Methodology ◽  
Content Type ◽  
Freeform Fabrication ◽  
Simulation Based ◽  
Simulation Results

Purpose The purpose of this study is to simulate the temperature distribution during an electron beam freeform fabrication (EBF3) process based on a fully threaded tree (FTT) technique in various scales and to analyze the temperature variation with time in different regions of the part. Design/methodology/approach This study presented a revised model for the temperature simulation in the EBF3 process. The FTT technique was then adopted as an adaptive grid strategy in the simulation. Based on the simulation results, an analysis regarding the temperature distribution of a circular deposit and substrate was performed. Findings The FTT technique was successfully adopted in the simulation of the temperature field during the EBF3 process. The temperature bands and oscillating temperature curves appeared in the deposit and substrate. Originality/value The FTT technique was introduced into the numerical simulation of an additive manufacturing process. The efficiency of the process was improved, and the FTT technique was convenient for the 3D simulations and multi-pass deposits.

Numerical Simulation of Progressive Collapse and Study of Resisting Progressive Collapse of Spatial Grid Structures Based on ANSYS/LS-DYNA

2011 ◽  
Vol 243-249 ◽  
pp. 6202-6205 ◽  
Author(s):  
You Liang Fang ◽  
Zhen Zong Zhao
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Design Method ◽  
Progressive Collapse ◽  
Reference Value ◽  
Grid Structure ◽  
Alternate Path Method ◽  
Spatial Grid

In this paper, different destruction forms of spatial grid structure are analyzed based on LS-DYNA. The key members of structure are studied and the collapsing processes of spatial grid structure caused by different failure members are simulated numerically. By comparing the results of numerical analysis, divisional design method is proposed based on the alternate path method (AP method). The divisional design method can improve resistance to progressive collapse obviously and is of certain reference value for engineering.

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.

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