Study on Electromagnetic Heating Process of Wind Power Gear: Temperature Morphology and Evolution

2020 ◽  
Vol 13 (3) ◽  
Author(s):  
Huaiyu Wen ◽  
Yi Han ◽  
Xiaobo Zhang ◽  
Feng Liu ◽  
Hongwang Zhang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Wind Turbine ◽  
Tooth Profile ◽  
Maximum Temperature ◽  
Heating Process ◽  
Central Section ◽  
Maximum Temperature Difference ◽  
Constant Change ◽  
Boltzmann Function

Abstract As a key component of wind turbine, the surface strengthening treatment of wind turbine gear is crucial to enhance its performance and service life. In the process of tooth-by-tooth induction heating, clear temperature distribution and process evolution could realize the lean control of heating effect and quality. In this article, the tooth-by-tooth heating process under the v-shaped inductor was studied to analyze the temperature field morphology and its evolution process. The results show that in the tooth profile region, the boundary morphology of the temperature field near the central section of the heating region conforms to the Boltzmann function, while the far sections conform to the normal distribution. At the end of heating, from the surface to the depth of the heating layer and from the heating center to both sides, both the maximum temperature difference and the distribution temperature are reduced. Meanwhile, the maximum temperature point near the central section is offset during the evolution of the temperature field morphology. The change of physical properties of materials and induced eddy distribution caused by involute structure and the constant change of temperature gradient are the fundamental reasons for the appearance of nonuniform temperature field and temperature excursion. The spatiotemporal variation of the hottest point was found, and the temperature morphology and evolution were revealed, which would provide a theoretical basis for adjusting the temperature distribution of tooth profile according to the requirements of different heating layers.

Simulation and Optimization of Temperature Field of Tank Cover with Super Large Diameter during the Creep Aging Forming Process

2021 ◽  
Vol 315 ◽  
pp. 3-9
Author(s):  
Yuan Gao ◽  
Li Hua Zhan ◽  
Hai Long Liao ◽  
Xue Ying Chen ◽  
Ming Hui Huang
Keyword(s):  
Temperature Field ◽  
Field Distribution ◽  
Temperature Difference ◽  
Single Stage ◽  
Maximum Temperature ◽  
Heating Process ◽  
Temperature Field Distribution ◽  
Two Stage ◽  
Maximum Temperature Difference ◽  
Forming Accuracy

The uniformity of temperature field distribution in creep aging process is very important to the forming accuracy of components. In this paper, the temperature field distribution of 2219 aluminum alloy tank cover during aging forming is simulated by using the finite element software FLUENT, and a two-stage heating process is proposed to reduce the temperature field distribution heterogeneity. The results show that the temperature difference of the tank cover is large in the single-stage heating process, and the maximum temperature difference is above 27°C,which seriously affects the forming accuracy of the tank cover. With two-stage heating process, the temperature difference in the first stage has almost no direct impact on the forming accuracy of the top cover. In the second stage, the temperature difference of the tank cover is controlled within 10°C, compared with the single-stage heating, the maximum temperature difference is reduced by more than 17°C. The two-stage heating effectively reduces the heterogeneity of the temperature field of the top cover. The research provides technical support for the precise thermal mechanical coupling of large-scale creep aging forming components.

scholarly journals Two-channel time-optimal control of induction heating process with maximum temperature constraint

2020 ◽  
Vol 28 (2) ◽  
pp. 41-58
Author(s):  
Natalya A. Il`ina
Keyword(s):  
Optimal Control ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Induction Heating ◽  
Time Optimal Control ◽  
Maximum Temperature ◽  
Heating Process ◽  
Problem Of Time ◽  
Control Actions ◽  
Time Optimal

The formulation and method of solution of the problem of time-optimal control of induction heating process of an unlimited plate with two control actions on the value of internal heat sources with technological constraint in relation to a one-dimensional model of the temperature field are proposed. The problem is solved under the conditions of a given accuracy of uniform approximation of the final temperature distribution over the thickness of the plate to the required. The method of finite integral transformations is used to search for the input-output characteristics of an object with distributed parameters with two control actions. The preliminary parameterization of control actions based on analytical optimality conditions in the form of the Pontryagin maximum principle is used. At the next stage reduction is performed to the problem of semi-infinite optimization, the solution of which is found using the alternance method. The alternance properties of the final resulting temperature state at the end of the optimal process lead to a basic system of relations, which, if there is additional information about the shape of the temperature distribution curve, is reduced to a system of equations that can be solved. An example of solving the problem of time-optimal control of temperature field of an unlimited plate with two offices is carried out in two stages. At first stage the case of induction heating without maximum temperature constraints is considered, at the second stage is carried out on the basis of the results of the first stage to obtain the solution subject to the limitation on the maximum temperature of the heated billet.

Model and Imitation of the Cycle Temperature Fields and Deformations of Coke Drum

2011 ◽  
Vol 197-198 ◽  
pp. 1389-1394
Author(s):  
Sun Yi Chen
Keyword(s):  
Temperature Field ◽  
Temperature Difference ◽  
Cooling Water ◽  
Physical Property ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Kinetic Temperature ◽  
Maximum Temperature Difference ◽  
Radial Temperature ◽  
Inside Wall

When the operating process of delay coking is cyclically changing from 25°C to 500°C, it would usually induce the effect of heat treatment on the shell of coke drum. After a special model of the kinetic medium climbing along the inside-wall of the coke drum at a steady rate set up, the resulting two-dimensional kinetic temperature field of shell in radial and axial directions has been calculated and analyzed by FEM. The relation between the material physical property of the shell and its temperature has been considered. The results show that the radial temperature difference or the axial temperature difference caused by the cooling water is more than that caused by the hot oil. The maximum temperature difference between the inside-wall and the outside-wall is 40°C below the medium level, 30mm by the hot oil and 60 °C or 25 mm by the cooling water. The circumferential uneven temperature field, location and concave/convex or incline/bend of body have been surveyed and analyzed. The lat-circle deformation of transverse section has been discussed.

A Study on Storing Process of Thermoforming Using Finite Difference Method

2011 ◽  
Vol 314-316 ◽  
pp. 571-575
Author(s):  
Zhen Zhe Li ◽  
Gui Ying Shen ◽  
Xiao Qian Wang ◽  
Mei Qin Li ◽  
Yun De Shen
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Finite Difference Method ◽  
Initial Temperature ◽  
Thickness Distribution ◽  
Time Dependent ◽  
Maximum Temperature ◽  
Uniform Thickness ◽  
Maximum Temperature Difference

Obtaining a uniform thickness of the final product using thermoforming is difficult, and the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the time-dependent temperature distribution of the total sheets in the storing process was studied because the temperature after the storing process is the initial temperature of the preheating process. An analysis code for simulating the storing process was developed under the condition that the thermal conductivity caused by contact resistance between sheets was assumed as a large value. In this study, the number of sheets in the storing room was adjusted for finding out the effect of it. The analysis results show that maximum temperature difference between sheets was significantly different when adjusting the number of sheets in the storing room. The temperature distribution of the total sheets and the method for analysis in this study will be used to optimize the storing process for higher quality of final products.

Temperature Field Numerical Simulation Analysis of 1000MW Ultra Supercritical Boiler’s Starting Water Separator

2012 ◽  
Vol 482-484 ◽  
pp. 651-654
Author(s):  
Na Li ◽  
Feng Ye
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Simulation Analysis ◽  
Element Model ◽  
Maximum Temperature ◽  
Safe Operation ◽  
Maximum Temperature Difference ◽  
Start Up ◽  
Water Separator ◽  
Distribution Laws

Aiming at the structural feature of starting water separator, a 3-D finite element model of temperature field is proposed. The starting water separator of a Ultra Supercritical Boiler(USB) has been numerically simulated by using of finite element soft ware Ansys. The boundary condition of the separator is determined. All of the working conditions are simulated. The results have the same distribution laws with the monitoring data of power plant. The maximum temperature difference between out wall and inner wall occurs in the temperature-rise period during the cold start-up, but the value between top wall and bottom wall is very lower. The simulation results can not only provide a basis for the thermal stress analysis and the life loss calculation but also provide rationalization proposal for the plant safe operation.

scholarly journals Analysis of Sunshine Temperature Field of Steel Box Girder Based on Monitoring Data

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Hailin Lu ◽  
Jing Hao ◽  
Jiwei Zhong ◽  
Yafei Wang ◽  
Hongyin Yang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Temperature Gradient ◽  
Maximum Temperature ◽  
Temperature Model ◽  
Bridge Site ◽  
Vertical Temperature Gradient ◽  
Vertical Temperature ◽  
Box Girder ◽  
Steel Box Girder

In this study, based on the recorded meteorological data of the bridge site, a spatial-temporal temperature model of a 3-span steel box girder is developed through applying the thermal analysis software TAITHERM. Firstly, the rationality and dependability of the proposed spatial-temporal temperature model are adequately verified by means of implementing the comparison with the measurement data. Then the temperature distribution of the steel box girder is analyzed and discussed in detail. The analytical results show that the time of the bottom of pavement reaching the daily maximum temperature lags behind the top of pavement by 2 or 3 hours due to the thermal insulation effect of pavement, and the maximum vertical temperature gradient of the structure exceeds the existing standards. Moreover, with the help of the analytical model, a parametric study of comprehensively meteorological factors is also performed. The results of the sensitivity analysis indicate that solar radiation is the most significant factor affecting the maximum vertical temperature gradient of the steel box girder, followed by air temperature and wind speed. After that, with the representative values of the extreme meteorological parameters during 100-year return period in Wuhan City in China being considered as the thermal boundary conditions, the temperature distribution of the steel box girder is further studied for investigation purpose. The results demonstrate that the heat conduction process of the steel box girder has distinct “box-room effect,” and it is of great necessity to consider both the actual weather conditions at the bridge site and the “box-room effect” of steel box girder when calculating thermal behaviors of bridge structures. Finally, it is related that the particular method proposed in this paper possesses a satisfactory application prospect for temperature field analysis upon various types of bridges in different regions.

Fabrication of a Cell Culture Plate With a Three-Dimensional Printed Mold and Thermal Analysis of PDMS-Based Casting Process

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
Myo Min Zaw ◽  
William D. Hedrich ◽  
Timothy Munuhe ◽  
Mohamad Hossein Banazadeh ◽  
Hongbing Wang ◽  
...  
Keyword(s):  
Cell Culture ◽  
Temperature Distribution ◽  
Fused Deposition Modeling ◽  
Thermal Damage ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Curing Temperature ◽  
Maximum Temperature ◽  
Maximum Temperature Difference ◽  
Fused Deposition

Abstract Polydimethylsiloxane (PDMS)-based casting method was used to fabricate PDMS cell culture platforms with molds printed by a fused deposition modeling (FDM) printer. Cell viability study indicated that the produced plates have the suitable biocompatibility, surface properties, and transparency for cell culture purposes. The molds printed from acrylonitrile-butadiene-syrene (ABS) were reusable after curing at 65 °C, but were damaged at 75 °C. To understand thermal damage to the mold at elevated temperatures, the temperature distribution in an ABS mold during the curing process was predicted using a model that considers conduction, convection, and radiation in the oven. The simulated temperature distribution was consistent with the observed mold deformation. As the maximum temperature difference in the mold did not change appreciably with the curing temperature, we consider that the thermal damage is due to the porous structure that increases the thermal expansion coefficient of the printed material. Our study demonstrated that FDM, an affordable and accessible three-dimensional (3D) printer, has great potential for rapid prototyping of custom-designed cell culture devices for biomedical research.

Numerical Simulation of Turbulent Heat Transfer on a Rotating Disk With an Impinging Jet

2010 ◽  
Author(s):  
M. H. Saidi ◽  
H. Karrabi ◽  
H. B. Avval ◽  
A. Asgarshamsi
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Rotating Disk ◽  
Turbulent Heat Transfer ◽  
Maximum Temperature ◽  
Turbulent Heat ◽  
Cooling Process ◽  
Maximum Temperature Difference

A numerical study has been earned out to investigate the fluid flow structure and convective heat transfer due to a circular jet impinging on a rotating disk. The temperature distribution and convection heat transfer coefficient on the disk are calculated. Flow is considered to be steady, incompressible and turbulent. k-ε RNG model is used to model the turbulent flow. Two new criteria are introduced and used to evaluate the performance of cooling process which are maximum temperature difference on the disk and the average temperature of the disk. The first parameter shows the uniformity of temperature distribution in the disk and the second shows the effect of both thermo physical properties of the disk material and cooling process. In order to verify the numerical approach, results have been compared with the experimental data which shows a good agreement.

Real Time Temperature Simulation on Caohe River Aqueduct in South to North Water Transfer Project During Construction Period

2011 ◽  
Vol 255-260 ◽  
pp. 1270-1274 ◽  
Author(s):  
Ping Zhang ◽  
Bin Tian
Keyword(s):  
Temperature Field ◽  
Water Transfer ◽  
Maximum Temperature ◽  
Long Distance ◽  
Maximum Temperature Difference ◽  
Construction Period ◽  
Cracking Control ◽  
Temperature Filed ◽  
North Water ◽  
Emergency Water Supply

The cracking control standard of water delivery structure is quite strict especially for middle-route of south-to-north water transfer project with long distance water transfer, large discharge, the crack prevention standard is extraordinary strict and must be reached. Early crack during construction period will affect safe operation of aqueduct, and diurnal variation of air temperature has significant effect on temperature field of thin-walled structure. Construction process simulation and temperature filed calculation during construction period about Caohe river landing rectangle aqueduct of Beijing-Shijiazhuang emergency water supply engineering of middle-route of south-to-north water transfer project are carried out by FEM , and compared with the monitoring temperature. The comparison result shows that temperature field during construction can be accurately simulated by calculation, which is helpful for guiding construction and choosing construction scheme, and worthy to popularize to other similar projects. From the calculation and monitoring, the maximum temperature difference is less than the standard, so there will be no serous cracks during construction in Caohe river aqueduct.

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.

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