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.

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.

Design and Analysis for Thermal Control System of Nanosatellite

2010 ◽  
Author(s):  
Murat Bulut ◽  
Adem Kahriman ◽  
Nedim Sozbir
Keyword(s):  
Thermal Analysis ◽  
Thermal Model ◽  
Thermal Control ◽  
Temperature Data ◽  
Thermal Design ◽  
Analysis Tool ◽  
Control Analysis ◽  
Preliminary Design ◽  
Thermal Control System ◽  
Early Phases

It is desirable to be able to turn-around thermal analysis results in a couple of minutes early phases of a satellite thermal design. Therefore, ThermXL-spreadsheet-based Thermal Analysis Tool is one of the very flexible and easy-to-use tool that is suited to preliminary design of a nanosatellite. This paper focuses on the thermal design and the results of an initial analysis of the nanosatellite by using ThermXL. The goal of this study is to take suitable measures to ensure all the components will operate in their safe range of temperatures and also a proper heat rejection. The nanosatellite such as Cube Satellite (CubeSat) is a miniaturized satellite that has dimensions of 10cm × 10cm × 10cm and weights of 1kg. The thermal model of CubeSat was modelled and the thermal analysis was performed. The thermal control analysis on this CubeSat with passive thermal control has been conducted by the ThermXL program that provided by ITP Engines. Temperature distribution of solutions was computed with ThermXL. Temperature data met the need of the mission. The results of the temperatures show that the thermal design of nanosatellite is feasible.

Three-Dimensional Diffusion in Arbitrary Domain Using Generalized Coordinates for the Boundary Condition of the First Kind: Application in Drying

2012 ◽  
Vol 326-328 ◽  
pp. 120-125 ◽  
Author(s):  
V.S.O. Farias ◽  
Wilton Pereira Silva ◽  
C.M.D.P. Silva e Silva ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Boundary Condition ◽  
Diffusion Equation ◽  
Numerical Solution ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Transient State ◽  
Arbitrary Domain ◽  
Time Step ◽  
Generalized Coordinates ◽  
Computational Code

This work presents a three-dimensional numerical solution for the diffusion equation in transient state, in an arbitrary domain. For this end, the diffusion equation was discretized using the finite volume method with a fully implicit formulation and generalized coordinates, for the equilibrium boundary condition. For each time step, the system of equations obtained for a given structured mesh was solved by the Gauss-Seidel method. The computational code was developed in FORTRAN, using the CFV 6.6.0 Studio, in a Windows platform. The proposed solution was validated using analytical and numerical solutions of the diffusion equation for different geometries (orthogonal and non-orthogonal meshes). The analysis and comparison of the results showed that the proposed solution provides correct results for the cases investigated. The developed computational code was applied in the simulation of the drying of ceramic roof tiles for the following temperature: 55.6 °C. The analysis of the results makes it possible to affirm that the developed numerical solution satisfactorily describes the drying processes in this temperature.

Scalable Thermal Simulation of Powder Bed Fusion

2020 ◽  
Author(s):  
Yaqi Zhang ◽  
Vadim Shapiro ◽  
Paul Witherell
Keyword(s):  
Spatial Data ◽  
Manufacturing Process ◽  
Thermal Field ◽  
Three Dimensional ◽  
Thermal Simulation ◽  
Powder Bed Fusion ◽  
Time Step ◽  
Powder Bed ◽  
Field Evolution ◽  
Scan Path

Abstract Powder bed fusion (PBF) has become a widely used additive manufacturing (AM) technology to produce metallic parts. Since the PBF process is driven by a moving heat source, consistency in part production, particularly when varying geometries, has proven difficult. Thermal field evolution during the manufacturing process determines both geometric and mechanical properties of the fabricated components. Simulations of the thermal field evolution can provide insight into desired process parameter selection for a given material and geometry. Thermal simulation of the PBF process is computationally challenging due to the geometric complexity of the manufacturing process and the inherent computational complexity that requires a numerical solution at every time increment of the process. We propose a new thermal simulation of the PBF process based on the laser scan path. Our approach is unique in that it does not restrict itself to simulations on the part design geometry, but instead simulates the formation of the geometry based on the process plan of a part. The implication of this distinction is that the simulations are in tune with the as-manufactured geometry, meaning that calculations are more aligned with the process than the design, and thus could be argued is a more realistic abstraction of real-world behavior. The discretization is based on the laser scan path, and the thermal model is formulated directly in terms of the manufacturing primitives. An element growth mechanism is introduced to simulate the evolution of a melt pool during the manufacturing process. A spatial data structure, called contact graph, is used to represent the discretized domain and capture all thermal interactions during the simulation. The simulation is localized through exploiting spatial and temporal locality, which is based on known empirical data. This limits the need to update to at most a constant number of elements at each time step. This implies that the proposed simulation not only scales to handle three-dimensional (3D) printed components of arbitrary complexity but also can achieve real-time performance. The simulation is fully implemented and validated against experimental data and other simulation results.

scholarly journals Three-Dimensional Elastodynamic Analysis Employing Partially Discontinuous Boundary Elements

Algorithms ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 129
Author(s):  
Yuan Li ◽  
Ni Zhang ◽  
Yuejiao Gong ◽  
Wentao Mao ◽  
Shiguang Zhang
Keyword(s):  
Side Effect ◽  
Domain Boundary ◽  
Three Dimensional ◽  
Boundary Integral ◽  
Integration Scheme ◽  
Computational Accuracy ◽  
Time Step ◽  
Corner Points ◽  
Discontinuous Elements ◽  
The Time Domain

Compared with continuous elements, discontinuous elements advance in processing the discontinuity of physical variables at corner points and discretized models with complex boundaries. However, the computational accuracy of discontinuous elements is sensitive to the positions of element nodes. To reduce the side effect of the node position on the results, this paper proposes employing partially discontinuous elements to compute the time-domain boundary integral equation of 3D elastodynamics. Using the partially discontinuous element, the nodes located at the corner points will be shrunk into the element, whereas the nodes at the non-corner points remain unchanged. As such, a discrete model that is continuous on surfaces and discontinuous between adjacent surfaces can be generated. First, we present a numerical integration scheme of the partially discontinuous element. For the singular integral, an improved element subdivision method is proposed to reduce the side effect of the time step on the integral accuracy. Then, the effectiveness of the proposed method is verified by two numerical examples. Meanwhile, we study the influence of the positions of the nodes on the stability and accuracy of the computation results by cases. Finally, the recommended value range of the inward shrink ratio of the element nodes is provided.

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