Estimation of heat generation by using echo state network for diagnosing thermal characteristics

This study is motivated by the fact that temperature control is very important for the success of laser assisted milling. A transient three-dimensional thermal model is developed using finite element analysis for laser assisted milling (LAMill) of silicon nitride ceramics, and then validated through a series of experiments of laser assisted face milling. This study aims to explore the thermal characteristics in LAMill of silicon nitride ceramics and thus provide guidelines on parameter selection for future operations. In addition, heat generation associated with machining is considered, and the effects of laser power, feed, and cutting speed on temperature are investigated. Simulation results show that heat generation associated with machining can be neglected. Laser power is one critical parameter for successful operation of LAMill. Moreover, both feed and cutting speed can affect the operating temperatures by varying feed rate; however, once feed rate is fixed, they have a little impact on the operating temperatures.

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Analysis on Electrical and Thermal Characteristics of a No–Insulation HTS Coil Considering Heat Generation in Steady and Transient States

IEEE Transactions on Applied Superconductivity ◽

10.1109/tasc.2019.2898543 ◽

2019 ◽

Vol 29 (5) ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Huu Luong Quach ◽

Ji Hyung Kim ◽

Yoon Seok Chae ◽

Jae Hyung Moon ◽

Jung Hyup Ko ◽

...

Keyword(s):

Heat Generation ◽

Thermal Characteristics ◽

Transient States

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Thermal Management of Electronic Chips in a Channel Using Input Power to Control Flow Velocity

Journal of Electronic Packaging ◽

10.1115/1.3068322 ◽

2009 ◽

Vol 131 (1) ◽

Author(s):

Esam M. Alawadhi

Keyword(s):

Steady State ◽

Pressure Drop ◽

Thermal Management ◽

Heat Generation ◽

Electronic Device ◽

Thermal Characteristics ◽

Input Power ◽

Control Flow ◽

Steady State Condition ◽

Average Temperature

In this research, thermal management of an electronic device using the input power is investigated numerically using the finite element method. The considered geometry consists of a horizontal channel with three volumetrically heated chips mounted on the bottom wall of the channel. The magnitude of the channel’s inlet velocity is varied with the variation of heat generation in the chips. The thermal characteristics of the system are presented, and compared with thermal characteristics of a system at a steady state condition. The effect of the Reynolds number and the oscillating period of the heat generation on the chips’ average temperature and Nusselt number is presented. The pressure drop in the channel is also calculated. The results indicated that the transient operating condition causes temperature to be higher than steady state by more than 45%, and difference between the transient and steady operations is reduced if the frequency is high. However, flow frequency has nearly no effect on the pressure drop in the channel.

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Entropy Analysis and Thermal Characteristics of Reiner Philippoff Hybrid Nanofluidic Flow Via a Parabolic Trough of Solar Aircraft Wings: Keller Box Method

10.21203/rs.3.rs-763495/v1 ◽

2021 ◽

Author(s):

Tanveer Sajid ◽

Wasim Jamshed ◽

Faisal Shahzad ◽

Mohamed R. Eid ◽

Esra Karataş Akgül ◽

...

Keyword(s):

Thermal Conductivity ◽

Heat Generation ◽

Thermal Conductance ◽

Thermal Characteristics ◽

Aircraft Wings ◽

Keller Box Method ◽

Dissipative Flow ◽

The Status ◽

Thermal Radiations ◽

Radiation Heat Generation

Abstract Solar energy is about the study of solar radiations and a method to enhance the efficacy of solar aircrafts with the utilization of solar radiations and nanotechnology. Solar radiations has been considered a heat source. The heat transmission performance of the wings is scrutinized for the situation of various effects like thermal radiations, heat generation, variant thermal conductance, thermal conductivity, and viscidness dissipative flow. Entropy generation analysis has been carried out in the status of Reiner Philippoff nanofluid (RPNF). The performance of the solar aircraft wings (SACW) improves in relations of thermal transmission for the status of amplification in thermal radiation, heat generation, viscidness dissipative flowing, and thermal conductivity parameters.

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Research on the Digital Twin for Thermal Characteristics of Motorized Spindle

10.21203/rs.3.rs-767803/v1 ◽

2021 ◽

Author(s):

Jianying Xiao ◽

Fan Kai-Guo

Keyword(s):

Thermal Behavior ◽

Data Acquisition ◽

Heat Generation ◽

Prediction Accuracy ◽

Thermal Characteristics ◽

Data Acquisition System ◽

Acquisition System ◽

Motorized Spindle ◽

Digital Twin ◽

Twin System

Abstract With the increase of spindle speed, heat generation becomes the crucial problem of high-speed motorized spindle. In order to obtain the actual thermal behavior of a motorized spindle, a digital twin system for thermal characteristics is developed in this paper. The mechanism of digital twin for thermal characteristics is to simulate the thermal behavior of a machine tool through mapping and correcting the thermal boundary conditions using the data acquisition system and correction models. The proposed digital twin system includes three modules which are the digital twin software, the data acquisition system, and the physical model with embedding sensors. The digital twin software is developed based on the Qt with the C++ programming language and the secondary development of ANSYS. Correction models for thermal boundaries are proposed to correct the heat generation and thermal contact resistance using the temperatures measured by the data acquisition system at thermal key points. To verify the prediction accuracy of the digital twin system, an experiment is carried out on a motorized spindle. The experimental results show that the prediction accuracy of the digital twin system is greater than 95%. It is of great significance to improve the accuracy of thermal characteristics simulation and thermal optimization.

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Diagnosis of Abnormal Heat Generation in the Connection Part in Low Voltage MCCBs for Fire Risk Prediction

Fire science and engineering ◽

10.7731/kifse.2073bb81 ◽

2020 ◽

Vol 34 (5) ◽

pp. 42-49

Author(s):

Yeong-Mo Yeon ◽

Seung-Hee Kim

Keyword(s):

Heat Generation ◽

Low Voltage ◽

Circuit Breaker ◽

Thermal Characteristics ◽

Saturation Temperature ◽

Fire Risk ◽

Industrial Sites ◽

Phase Temperature ◽

Normal Current ◽

Temperature Test

This study is conducted to determine the critical temperature under normal current flow by estimating normal heat generation; the saturation temperature of the connecting part of a circuit breaker is simultaneously measured by sub-dividing the rated current of molded case circuit breaker (MCCB) into 10 steps. Further, a risk analysis was conducted via an investigation of thermal characteristics. To this end, five types of MCCBs were selected while building a temperature test box; further, the heat generation temperature of the three phases on the line and load sides was measured using the sub-divided load current to represent the electrical heat variation and a high-current-generating tester real-time. The results the test, demonstrate that the temperature of the connecting part of the MCCB stably increased; in addition, the standard of the heat generation could be established and the load amount could be predicted by measuring the temperature variation. Meanwhile, the heat generation temperature was different for different types of wirings such as power lines and Busbar. Further among the R, S, and T phases of the MCCB, S phase temperature was slightly higher than those of the others. This study can serve as a theoretical reference for future applied research on the dangers of fire due to the heat generation of the connecting part of the MCCB, wherein the risks of abnormal heat generation need to be analyzed. The results obtained can be applied not only to prevent the carbonization accidents of MCCBs installed inside distribution panels being used at industrial sites, but also to manage the risks of the distribution circuit breaker and prevent the electrical fire.

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Research on the influencing factors of thermal characteristics of high-speed grease lubricated angular contact ball bearing

Advances in Mechanical Engineering ◽

10.1177/16878140211027398 ◽

2021 ◽

Vol 13 (6) ◽

pp. 168781402110273

Author(s):

Chang Zhang ◽

Dan Guo ◽

Jiyin Tian ◽

Qingbo Niu

Keyword(s):

Thermal Expansion ◽

Heat Generation ◽

High Speed ◽

Ball Bearing ◽

Thermal Characteristics ◽

Generation Model ◽

Analysis Model ◽

Angular Contact Ball Bearing ◽

Bearing Contact ◽

Contact Parameters

The high temperature rise of grease lubricated angular contact ball bearing under high speed operation will affect the working accuracy of the bearing, and even lead to the loss of accuracy. In this paper, a friction heat generation model for high-speed grease lubricated angular contact ball bearing was established. Based on the quasi-static analysis model, the thermal expansion of the bearing components is brought into the quasi-static equilibrium equation, and the modified quasi-static analysis model of high-speed grease lubricated ACBB is obtained. Under grease lubrication conditions, a local bearing heat-generation model was employed to assess power losses in different contact zones, in which bearing contact parameters, external loads, and rotation speeds conditions were fully considered. Moreover, the temperature distribution of grease lubricated high-speed bearing was analyzed by the multi node thermal network method. Through the analysis model of bearing dynamic and thermal characteristics considering the influence of thermal expansion established, bearing contact parameters have significant differences. The calculated values of outer ring temperature of grease lubricated angular contact ball bearing is in good agreement with the experimental values. The model can predict the temperature values of grease lubricated angular contact ball bearing under axial load at high speed.

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Analysis of the Risk of Heat Generation due to Bolt Loosening in Terminal Block Connector Parts

Fire science and engineering ◽

10.7731/kifse.1b692d79 ◽

2020 ◽

Vol 34 (3) ◽

pp. 67-75 ◽

Cited By ~ 1

Author(s):

Yeong-Mo Yeon ◽

Seung-Hee Kim

Keyword(s):

Real Time ◽

Heat Generation ◽

Heating Temperature ◽

Electrical Contact ◽

Thermal Characteristics ◽

Risk Level ◽

Industrial Sites ◽

Temperature Detector ◽

Measurement And Analysis ◽

Terminal Block

In this study, the risk of heat generation due to normal and overload currents that vary with the abnormal loosening angle of wire-connecting bolts were identified. The risks were analyzed based on the thermal characteristics to minimize the carbonization accidents of terminal blocks inside distribution panels typically used in industrial sites. We applied a method for measuring the heating temperature and temperature variations in the terminal blocks in real-time by installing a resistance temperature detector sensor board in the terminal block. The experimental results showed that the terminal block model with a low-rated current exhibited a higher heating temperature, thus, confirming the need to select the terminal block capacity based on load currents. Additionally, the higher the rated current of the terminal block with a high-rated current and the higher the degree of loosening, the faster the carbonization point. Such heating temperature monitoring enabled real-time thermal temperature measurement and a step-by-step risk level setting through thermal analysis. The results of the measurement and analysis of carbonization risks can provide a theoretical basis for further research regarding the risk of fire due to carbonization. Furthermore, the deterioration measurement method using the temperature sensor board developed in this study is widely applicable to prevent fires caused by poor electrical contact as well as risk-level management.

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Study on the Thermal Characteristics of a Motorized Spindle Unit

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.479-481.2546 ◽

2012 ◽

Vol 479-481 ◽

pp. 2546-2550

Author(s):

Teng Qing Wu ◽

Heng Liu ◽

Min Qing Jing ◽

Hong Wei Fan

Keyword(s):

Water Flow ◽

Heat Generation ◽

High Performance ◽

Water Flow Rate ◽

Cooling Water ◽

Thermal Characteristics ◽

Motorized Spindle ◽

Flow Rates ◽

Cooling Water Flow Rate ◽

Spindle Unit

Heat generation and heat transfer of motorized spindle unit are studied in this paper, including heat generation of built-in motor and rolling bearings, heat conduction, convection and radiation between spindle components. By modeling a FEM model of a high performance motorized grinding spindle, thermal characteristics simulation of the spindle unit is completed. The thermal characteristics under different spindle speeds, different cooling water flow rates and different forced air flow rates are simulated. The numerical results show that spindle speed and cooling water flow rate have significant influences on thermal characteristics of motorized spindle unit. These results are useful to guide the design and verification of motorized spindle unit.

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