A Three-Dimensional Transient Thermal Model for Machining

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Coskun Islam ◽  
Ismail Lazoglu ◽  
Yusuf Altintas
Keyword(s):  
Mathematical Model ◽  
Thermal Model ◽  
Three Dimensional ◽  
Measurement Data ◽  
Time Discretization ◽  
Temperature Fields ◽  
Implicit Time ◽  
Machining Processes ◽  
Transient Thermal ◽  
Interrupted Turning

This article presents an enhanced mathematical model for transient thermal analysis in machining processes. The proposed mathematical model is able to simulate transient tool, workpiece, and chip temperature fields as a function of time for interrupted processes with time varying chip loads such as milling and continuous machining processes such as turning and drilling. A finite difference technique with implicit time discretization is used for the solution of partial differential equations to simulate the temperature fields on the tool, workpiece, and chip. The model validations are performed with the experimental temperature measurement data available in the literature for the interrupted turning of Ti6Al6V–2Sn, Al2024, gray cast iron and for the milling of Ti6Al4V. The simulation results and experimental measurements agree well. With the newly introduced modeling approach, it is demonstrated that time-dependent dynamic variations of the temperature fields are predicted with maximum 12% difference in the validated cases by the proposed transient thermal model.

scholarly journals Optimizing air velocity for the underfloor forced ventilation to protect a refrigerated warehouse from frost heaving

2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Frost Heave ◽  
Forced Ventilation ◽  
Air Velocity ◽  
Set Up

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.

Dynamic Response Modeling of Fluid-Solid Coupling for Wet Brake Disc

2013 ◽  
Vol 475-476 ◽  
pp. 1397-1401 ◽  
Author(s):  
Xun Jia Zheng ◽  
Tian Hong Luo ◽  
Ce Jia
Keyword(s):  
Mathematical Model ◽  
Dynamic Response ◽  
Three Dimensional ◽  
Brake Disc ◽  
Field Variation ◽  
Thermal Stress Field ◽  
Friction Plate ◽  
Transient Thermal ◽  
Response Modeling ◽  
Surface Temperature Field

Due to the poor conditions of wet brake cooling and the high temperature of the working characteristics, this paper intended to introduce the oil film vadose between the brake linings, considered the variation of volume of grooves on the friction plate, and then proposes the three-dimensional transient dynamic response of fluid-solid coupling mathematical model. By numerical analysis of the disc transient thermal stress field distribution on the friction plate, the friction surface temperature field variation is obtained. Finally, the results shows that the mathematical model is effective and feasible.

Investigation Regarding Transient Compact Thermal Model for Microprocessor Packages

2019 ◽  
Author(s):  
Koji Nishi
Keyword(s):  
Power Efficiency ◽  
Thermal Model ◽  
Three Dimensional ◽  
Transient State ◽  
Thermal Control ◽  
Computing System ◽  
Thermal Simulation ◽  
Thermal Design ◽  
Time Step ◽  
Transient Thermal

Abstract In recent years, not only static thermal design but also realtime thermal control become important for power efficiency on computing systems. Three-dimensional thermal simulation is widely used to design computing system, however, it takes too long time for intelligent power and thermal management validation because it requires transient thermal simulation with very short time step. To enable rapid simulation environment, compact thermal model which can be employed with both three-dimensional transient thermal simulation and transient thermal network is required. Therefore, this research aims to establish transient state compact thermal model for microprocessor package. This paper briefly introduces steady state compact thermal model for microprocessor, which is proposed as previous work, then, points out key point to extend the model to transient state model. Transient thermal spreading resistance is emulated and the effect is checked by comparing with three-dimensional simulation.

scholarly journals Mathematical Modelling of Biomechanical Interactions between Backpack and Bearer during Load Carriage

2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Lei Ren ◽  
David Howard ◽  
Richard K. Jones
Keyword(s):  
Mathematical Model ◽  
Mathematical Modelling ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Measurement Data ◽  
Load Carriage ◽  
Human Gait ◽  
Test Rig ◽  
Interaction Forces ◽  
Suspension Model

This paper proposes a three-dimensional mathematical model of the biomechanical interactions between backpack and bearer during load carriage. The model considers both the coupled pack motions, which follow the torso, and also the longitudinal compliance and damping in the backpack suspension. The pack interaction forces and moments, acting on the bearer, are determined from kinematic relationships, equations of motion, and a dynamic pack suspension model. The parameters of the pack suspension model were identified from test data obtained using a load carriage test rig. Output from the load carriage mathematical model has been compared with measurement data during human gait and conclusions drawn with regard to the validity of the proposed approach.

Finite Element Modeling for Analyzing Material Removal Rate in ECDM Process

2020 ◽  
Vol 19 (04) ◽  
pp. 815-835 ◽  
Author(s):  
Viveksheel Rajput ◽  
Mudimallana Goud ◽  
Narendra Mohan Suri
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Material Removal Rate ◽  
Thermal Model ◽  
Material Removal ◽  
Removal Rate ◽  
Experimental Results ◽  
Temperature Fields ◽  
Work Material ◽  
Transient Thermal

Electrochemical discharge machining (ECDM) has been developed as a hybrid and robust technology for machining non-conductive work material at a preferable removal rate. ECDM exhibits various applications in the micro-machining of these materials like nuclear, automotive, medical industries, etc. Due to some peculiar properties of nonconductive materials, for example, glass transparency, their utilization in MEMS applications are also very numerous. In the ECDM process, removal of material takes place primarily due to high-temperature thermal erosion and secondarily due to electrolyte chemical etching action. Many rigorous experimental studies have reported in the empirical estimation of the material removal rate (MRR) in the ECDM process. However, very few studies have reported in the modeling of the ECDM process for predicting material removal rate through single spark simulation. The present paper attempts to develop a transient thermal model based upon finite element modeling (FEM) to simulate a single spark in the ECDM process for obtaining temperature fields in the work material. The obtained temperature fields are further post-processed to predict the material removal rate. FEM results are compared with the previous simulated and experimental results to confirm the approach. Moreover, an experimental study is also performed to validate the developed thermal model and it was found to be in an acceptable range of the experimental results. Further, a parametric study revealed that MRR increases with the increase in applied voltage and electrolyte concentration during soda-lime glass machining with ECDM. The developed FEM-based transient thermal model can be successfully utilized for predicting the removal rate of nonconductive work material.

Numerical Simulation of Laser Soldering about Electronic Connectors

2013 ◽  
Vol 668 ◽  
pp. 534-537 ◽  
Author(s):  
Yi Liu ◽  
Xun Bo Li ◽  
Zhi Zeng ◽  
Tao Liu
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Thermal Model ◽  
Temperature Fields ◽  
Ansys Software ◽  
3D Finite Element ◽  
Maximum Deformation ◽  
Laser Soldering ◽  
3D Finite Element Method ◽  
Transient Thermal

A transient thermal model for Micro USB V2.0 electronic connector was created based on 3D finite element method. Then get the laser soldering spots on the temperature and stress the distribution of simulation by ANSYS software. Temperature fields at different time, residual stress in different locations and deformations were analyzed. The result shown that the maximum deformation of metal-pin reached 1.4mm, achieved the process standard.

scholarly journals Multilinear POD-DEIM model reduction for 2D and 3D semilinear systems of differential equations

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Gerhard Kirsten
Keyword(s):  
Differential Equations ◽  
Differential Operators ◽  
Interpolation Method ◽  
Three Dimensional ◽  
Order Reduction ◽  
Time Discretization ◽  
Three Dimensions ◽  
Implicit Time ◽  
Benchmark Problems ◽  
Tensor Form

<p style='text-indent:20px;'>We are interested in the numerical solution of coupled semilinear partial differential equations (PDEs) in two and three dimensions. Under certain assumptions on the domain, we take advantage of the Kronecker structure arising in standard space discretizations of the differential operators and illustrate how the resulting system of ordinary differential equations (ODEs) can be treated directly in matrix or tensor form. Moreover, in the framework of the proper orthogonal decomposition (POD) and the discrete empirical interpolation method (DEIM) we derive a two- and three-sided model order reduction strategy that is applied directly to the ODE system in matrix and tensor form respectively. We discuss how to integrate the reduced order model and, in particular, how to solve the tensor-valued linear system arising at each timestep of a semi-implicit time discretization scheme. We illustrate the efficiency of the proposed method through a comparison to existing techniques on classical benchmark problems such as the two- and three-dimensional Burgers equation.</p>

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