Thermal Characteristics Analysis of Aerostatic Direct Drive Rotary Stage

2013 ◽  
Vol 655-657 ◽  
pp. 287-291
Author(s):  
Cong Peng Zhang ◽  
Mei Bo Li ◽  
Xue Ke Luo
Keyword(s):  
Heat Dissipation ◽  
Thermal Structure ◽  
Thermal Characteristics ◽  
Simulation Models ◽  
Structural Deformation ◽  
Transient Temperature ◽  
Direct Drive ◽  
Rotary Stage ◽  
Transient Temperature Field ◽  
Characteristics Analysis

A precision air bearing rotary stage driven by direct-driven motor is proposed. The structural characteristic of the rotary system is introduced, and the mechanism of structural thermal deformation and heat dissipation of aerostatic direct drive rotary stage were analyzed. The simulation models of static and transient temperature field are built, and thermal-structure coupled filed is calculated. The internal steady thermal field diagram and key nodes temperature curve of the rotary stage are obtained. Based on the temperature analysis results, the rotary stage structural deformation is established. The cooling method is provided, and result shows that the cooling way is effective.

scholarly journals Investigations on Temperature Fields during Laser Beam Melting by Means of Process Monitoring and Multiscale Process Modelling

2014 ◽  
Vol 6 ◽  
pp. 217584 ◽  
Author(s):  
J. Schilp ◽  
C. Seidel ◽  
H. Krauss ◽  
J. Weirather
Keyword(s):  
Process Monitoring ◽  
Manufacturing Process ◽  
Computation Time ◽  
Simulation Models ◽  
Process Models ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Transient Temperature Field ◽  
Laser Beam Melting ◽  
Simulation Based

Process monitoring and modelling can contribute to fostering the industrial relevance of additive manufacturing. Process related temperature gradients and thermal inhomogeneities cause residual stresses, and distortions and influence the microstructure. Variations in wall thickness can cause heat accumulations. These occur predominantly in filigree part areas and can be detected by utilizing off-axis thermographic monitoring during the manufacturing process. In addition, numerical simulation models on the scale of whole parts can enable an analysis of temperature fields upstream to the build process. In a microscale domain, modelling of several exposed single hatches allows temperature investigations at a high spatial and temporal resolution. Within this paper, FEM-based micro- and macroscale modelling approaches as well as an experimental setup for thermographic monitoring are introduced. By discussing and comparing experimental data with simulation results in terms of temperature distributions both the potential of numerical approaches and the complexity of determining suitable computation time efficient process models are demonstrated. This paper contributes to the vision of adjusting the transient temperature field during manufacturing in order to improve the resulting part's quality by simulation based process design upstream to the build process and the inline process monitoring.

scholarly journals Direct-Drive Bi-Rotary Milling Head Variable Load Thermal Characteristics Analysis

2012 ◽  
Vol 3 ◽  
pp. 270-276 ◽  
Author(s):  
Shiwei Hu ◽  
Qingdong Yang ◽  
Baoying Peng ◽  
Hongzhi Wang
Keyword(s):  
Thermal Characteristics ◽  
Variable Load ◽  
Direct Drive ◽  
Characteristics Analysis

Study on the Influence of Temperature and Stress Field to PCB’s Modal

2012 ◽  
Vol 271-272 ◽  
pp. 1441-1445
Author(s):  
Qin Luo ◽  
Su Juan Zhang ◽  
Xiao Zhang
Keyword(s):  
Temperature Field ◽  
Stress Field ◽  
Modal Analysis ◽  
Heat Flux Density ◽  
Heat Dissipation ◽  
Transient Temperature ◽  
Electronic Products ◽  
Transient Stress ◽  
Transient Temperature Field ◽  
Pcb Design

With the increasing integration of electronic products, the heat flux density is increasing. Research on the heat dissipation of the PCB attracts more attention. Temperature field of the electronic products always changes a lot, usually leading to a transient stress field in the PCB. Due to the transient temperature field and transient stress field, the PCB’s modal changed. In this paper, the temperature field and the stress field are obtained to explain the reason of the change. The influence on PCB’s modal caused by the temperature field and the stress field are analyzed, on the basis of PCB’s thermal modal analysis, which provide a reference for the PCB design and modal analysis in the future.

Numerical Analysis of Transient Temperature Field and Thermal Stress on Coke Drum With 1.25Cr-0.5Mo Steel Based on Iterative Algorithm

2017 ◽  
Author(s):  
Zhibing Lu ◽  
Xuedong Chen ◽  
Zhichao Fan ◽  
Jie Dong ◽  
Jinhua Zhu
Keyword(s):  
Temperature Field ◽  
Thermal Stress ◽  
Iterative Algorithm ◽  
Thermal Structure ◽  
Transient Temperature ◽  
Main Process ◽  
Measured Temperature ◽  
Operating Cycle ◽  
Transient Temperature Field ◽  
Variation Characteristics

Coke drum is typical industrial equipment which experiences complex thermal and mechanical cyclic load during its operation, and the thermal stress which is produced by the drastic change of temperature is the main cause of the cracking failure of coke drum. This paper aims at coke drum with 1.25Cr–0.5Mo steel, and is based on iterative algorithm. Then we simulate the process of liquid medium climbing the inner surface of coke drum in the stages of oil filling and water quenching with dynamic thermal boundary, and carry out the numerical calculation of transient temperature field of coke drum in main process stages for one operating cycle. After the comparison of simulated temperature values with the measured temperature data at several locations on the outer surface of coke drum, the appropriate equivalent coefficients of convective heat transfer will be obtained. The variation rules of transient temperature field for the key parts of coke drum are discussed. Based on the simulation results of temperature field, the thermal-structure coupling analysis of coke drum is carried out, and the variation characteristics of thermal stress on coke drum are studied later.

Thermal Structure Coupling Analysis of Lathe Built-In Electric Spindle under Intermittent Load

2014 ◽  
Vol 989-994 ◽  
pp. 2922-2925
Author(s):  
Ke Wang ◽  
Ji Hang Liu ◽  
Guo Kui Wu ◽  
Xing Wei Sun
Keyword(s):  
Thermal Deformation ◽  
Thermal Structure ◽  
Internal Heat ◽  
Thermal Error ◽  
Internal Heat Source ◽  
Transient Temperature ◽  
Analysis Model ◽  
Time Curve ◽  
Transient Temperature Field ◽  
Thermal Error Compensation

Built-in electric spindle has been the core component of machine tool, whose temperature problem is serious. Internal heat source are greatly influenced by load. Based on which has the function of automatic clipping chuck inversion type vertical lathe built-in electric spindle prototype as the research object, using the theory of thermal stress and finite element, established the intermittent load cases hot - structure coupling numerical analysis model of the electric spindle. After overall analyzing electric spindle within the transient temperature field under the action of the intermittent load, the winding temperature changing with time curve is given. On that basis, electric spindle thermal deformation has been carried on the analysis and calculation, gets the shaft extension end axial thermal deformation, provides theoretical basis for the thermal error compensation.

Modeling and Estimating Thermal Error in Precision Machine Spindles

2010 ◽  
Vol 34-35 ◽  
pp. 507-511 ◽  
Author(s):  
Jian Han ◽  
Li Ping Wang ◽  
Lian Qing Yu
Keyword(s):  
Finite Element ◽  
Thermal Deformation ◽  
Thermal Structure ◽  
Thermal Characteristics ◽  
Thermal Error ◽  
Transient Temperature ◽  
Axial Deformation ◽  
Analysis Model ◽  
Element Analysis ◽  
Spindle System

Thermal induced errors are significant factors that affect machine tool accuracy. The deformation of spindle is the main contributor to thermal error. In this paper, the thermal characteristics of the spindle system are investigated. Taking into account the coupling of elastic deformation and temperature, the heat conduction of the spindle system is modeled. The heat of bearings and heat transfer coefficient, and boundary conditions of the spindle are determined. Based on the numerical results, an iterative model of spindle's temperature and thermal deformation are acquired under the actions of thermal loads using the finite element method. Taking the spindle of precision boring machine with some reasonable assumptions and simplicities as an example, the finite element analysis model of spindle thermal characteristics is analyzed with virtual prototyping, and the static/transient temperature field and thermal-structure field are calculated using ABAQUS software. The characteristics of heat flow and thermal deformation within the spindle are analyzed according to the simulation results. The research results provide a theoretical foundation for reasonable arrangement and optimal design to reduce radial and axial deformation of the spindle head, temperature controlling, and the error compensation to the precision machining tool.

ANSYS Analysis on Thermal Structure of Bionic Brake Discs

2015 ◽  
Vol 789-790 ◽  
pp. 430-435
Author(s):  
Li Xin Wang ◽  
Ya Yan Gao ◽  
Li Qiang Peng ◽  
Li Gang Zhai
Keyword(s):  
Smooth Surface ◽  
Heat Dissipation ◽  
Thermal Structure ◽  
Field Analysis ◽  
Transient Temperature ◽  
Brake Disc ◽  
Brake Discs ◽  
Thermal Wear ◽  
Brake Performance ◽  
Braking Process

The failure of brake performance, which is caused by thermal recession under the emergency brake, results in traffic accident frequently. Based on excellent wear-resisting properties of locust’s non-smooth surface structure, bionic brake disc with special surface micro-structure was designed. According to the thermal analysis theory, transient temperature field analysis of the bionic brake disc during the braking process under different initial velocity was analyzed. The results showed that bionic brake disc has excellent heat dissipation ability, which is beneficial to improve the brake performance. The non-smooth surface can store air and dissipate heat, thus reducing the thermal fatigue and thermal wear caused by temperature rise. This research provides a theoretical basis for designing bionic brake discs with excellent heat dissipation performance.

Study on Simulation of Temperature Field and Optimization of Structure to Grounding Resistor

2014 ◽  
Vol 986-987 ◽  
pp. 1864-1868
Author(s):  
Da Jiang He ◽  
Peng Fei Shao ◽  
Hen Ling Yang ◽  
Jing Xiao ◽  
Jun Qu
Keyword(s):  
Temperature Field ◽  
Cost Saving ◽  
Engineering Application ◽  
Structure Optimization ◽  
Simulation Models ◽  
Transient Temperature ◽  
Distribution Characteristics ◽  
Design Efficiency ◽  
Transient Temperature Field ◽  
The Cost

According to the structure of grounding resistor, the flow-current experiments of alloy materials which have different performance and specification have been done in the condition of simulation grounding fault. Based on the experiments, the simulation models of temperature field have been constructed; the distribution characteristics of the transient temperature field and the structure optimization of Grounding Resistor have been studied and discussed by the simulation models. The research results have a great engineering application value on the optimization of performance, the choice of the materials, the cost saving and the improvement of design efficiency to grounding resistor.

Thermal-Structure Coupling Numerical Simulation of a Special-Type Plug Nozzle

2011 ◽  
Vol 217-218 ◽  
pp. 1510-1515
Author(s):  
Bo Yi Zhang ◽  
Wei Qiang Liu
Keyword(s):  
Heat Transfer ◽  
Working Conditions ◽  
Thermal Structure ◽  
Convective Heat Transfer Coefficient ◽  
Transient Temperature ◽  
Transfer Model ◽  
Thermal Distortion ◽  
Regenerative Cooling ◽  
Plug Nozzle ◽  
Transient Temperature Field

Two-dimensional transient heat transfer model of the plug of regenerative cooling plug nozzle is built. Based on the convective heat-transfer coefficient and the radiation heat flux obtained using analytic method and axisymmetric unstructured Delaunay grid applied to mesh the simplified physical model, numerical simulations of transient temperature field and thermal distortion are carried out by finite element method combined with thermal-structure coupling theory. Not only the results of numerical calculation under working conditions with and without regenerative cooling, but the results under low and high working conditions are compared. The results shows that thermal distortion can be reduced effectively when regenerative cooling method is adopted in the throat and combustion chamber that have the most serious thermal condition.

scholarly journals A Machine Learning Solution for Data Center Thermal Characteristics Analysis

2020 ◽  
Author(s):  
marta chinnici ◽  
Anastasiia GRISHIna ◽  
Ah-Lian KOR ◽  
Eric Rondeau ◽  
jean philippe georges
Keyword(s):  
Machine Learning ◽  
Energy Efficiency ◽  
Air Temperature ◽  
Data Center ◽  
Heat Dissipation ◽  
Waste Heat ◽  
Cooling System ◽  
Thermal Characteristics ◽  
Ambient Air ◽  
Characteristics Analysis

Energy efficiency of Data Center (DC) operations heavily relies on IT and cooling systems performance. A reliable and efficient cooling system is necessary to produce a persistent flow of cold air to cool servers that are subjected to constantly increasing computational load due to the advent of IoT- enabled smart systems. Consequently, increased demand for computing power will bring about increased waste heat dissipation in data centers. In order to bring about a DC energy efficiency, it is imperative to explore the thermal characteristics analysis of an IT room (due to waste heat). This work encompasses the employment of an unsupervised machine learning modelling technique for uncovering weaknesses of the DC cooling system based on real DC monitoring thermal data. The findings of the analysis result in the identification of areas for energy efficiency improvement that will feed into DC recommendations. The methodology employed for this research includes statistical analysis of IT room thermal characteristics, and the identification of individual servers that frequently occur in the hotspot zones. A critical analysis has been conducted on available big dataset of ambient air temperature in the hot aisle of ENEA Portici CRESCO6 computing cluster. Clustering techniques have been used for hotspots localization as well as categorization of nodes based on surrounding air temperature ranges. The principles and approaches covered in this work are replicable for energy efficiency evaluation of any DC and thus, foster transferability. This work showcases applicability of best practices and guidelines in the context of a real commercial DC that transcends the set of existing metrics for DC energy efficiency assessment.

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