Modeling Thermal Behavior of System-in-Package with Dynamic Compact Model

Integrating more functionality into smaller size increases the heat dissipation density and emphasizes the need for thermal simulations and accurate thermal models. With a compact thermal model (CTM) the dynamic and steady state thermal behavior of a package with several heat dissipating dice can be modeled. The optimization of the model's parameters requires a properly defined cost function. In this paper a two-phase optimization routine was used to find simultaneously good capacitance and resistance values. The accuracy of the model was improved when effective surface areas defined the convections of a CTM. Parameter optimization in time domain, for variable thermal load and nonlinear system, was tested and found accurate, but time consuming.

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Long-Term Evolution of SCD-1 Satellite Temperatures Based on Comparative Analysis of Telemetric Data Measured in Orbit

Journal of Heat Transfer ◽

10.1115/1.4033084 ◽

2016 ◽

Vol 138 (7) ◽

Author(s):

Andreia F. S. Genaro ◽

Ezio C. Garcia ◽

Issamu Muraoka ◽

Kevin E. de Conde

Keyword(s):

Mathematical Model ◽

Thermal Behavior ◽

Heat Dissipation ◽

Solar Spectrum ◽

Temperature Sensitive ◽

Term Evolution ◽

Optimization Routine ◽

Experimental Values ◽

The Mathematical Model

This paper presents results of the research investigation regarding the causes for temperature variation of the SCD-1 (data-collection satellite) by analyzing its thermal behavior evolution throughout 13 years in orbit. SCD-1, the first satellite designed and built in Brazil, was launched in 1993 and is still in operation. A mathematical model has been developed to simulate thermal behavior of SCD-1 in orbit, which was used as a working tool during project design phase, and is presented here. Temperatures of SCD-1 in orbit have been monitored and recorded in the Control and Tracking Center (São José dos Campos, SP, Brazil) since its launch. An analysis carried out at the mission’s beginning showed that all the temperatures were within the ranges predicted in model. Over the years, the battery, which is the most temperature-sensitive equipment in the satellite, had an increase in temperature approaching upper limit. A method has been developed to investigate the causes of this upswing in which an optimization routine linked to the mathematical model corrects a selected set of parameters in order to adjust the theoretical temperature values to the experimental values. By means of this methodology, data from SCD-1 were analyzed from 1995 to 2005 period and it was concluded that the rise in temperature was caused by an increase in internal battery heat dissipation and absorptivity in solar spectrum of some of the external satellite shielding, both consequences of a long-term degradation.

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Thermal Analysis of a Parallel-Configured Battery Pack (1S18P) Using 21700 Cells for a Battery-Powered Train

Electronics ◽

10.3390/electronics9030447 ◽

2020 ◽

Vol 9 (3) ◽

pp. 447

Author(s):

Taewoo Kang ◽

Seongyun Park ◽

Pyeong-Yeon Lee ◽

In-Ho Cho ◽

Kisoo Yoo ◽

...

Keyword(s):

Thermal Behavior ◽

Thermal Model ◽

Heat Dissipation ◽

State Of Charge ◽

Battery Pack ◽

Power Demand ◽

Equivalent Resistance ◽

Simulation And Experiment ◽

Characterization Test ◽

Demand Profile

In this study, the thermal behavior of a 1S18P battery pack is examined based on the power demand during train propulsion between two stations. The proposed thermal prediction model is classified into Joules heating with equivalent resistance, reversible heat, and heat dissipation. The equivalent resistances are determined by 5% of the state of charge intervals using the hybrid pulse power characterization test. The power demand profile during train propulsion between two stations is provided by the Korea Railroad Research Institute. An experiment is conducted to examine the 1S18P battery pack thermal behavior during the propulsion between two stations. A comparison of the simulation and experiment results validated the proposed thermal model.

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Effects of Varying Geometrical Parameters on Boiling From Microfabricated Enhanced Structures

Journal of Heat Transfer ◽

10.1115/1.1513575 ◽

2003 ◽

Vol 125 (1) ◽

pp. 103-109 ◽

Cited By ~ 52

Author(s):

C. Ramaswamy ◽

Y. Joshi ◽

W. Nakayama ◽

W. B. Johnson

Keyword(s):

Heat Dissipation ◽

Layer Structure ◽

Single Layer ◽

Nucleate Boiling ◽

Heat Fluxes ◽

Working Fluid ◽

Geometrical Parameters ◽

Small Range ◽

Two Phase ◽

Wall Superheat

The current study involves two-phase cooling from enhanced structures whose dimensions have been changed systematically using microfabrication techniques. The aim is to optimize the dimensions to maximize the heat transfer. The enhanced structure used in this study consists of a stacked network of interconnecting channels making it highly porous. The effect of varying the pore size, pitch and height on the boiling performance was studied, with fluorocarbon FC-72 as the working fluid. While most of the previous studies on the mechanism of enhanced nucleate boiling have focused on a small range of wall superheats (0–4 K), the present study covers a wider range (as high as 30 K). A larger pore and smaller pitch resulted in higher heat dissipation at all heat fluxes. The effect of stacking multiple layers showed a proportional increase in heat dissipation (with additional layers) in a certain range of wall superheat values only. In the wall superheat range 8–13 K, no appreciable difference was observed between a single layer structure and a three layer structure. A fin effect combined with change in the boiling phenomenon within the sub-surface layers is proposed to explain this effect.

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Numerical Study of a Cooling System Using Phase Change of a Refrigerant in a Thermosyphon

Energies ◽

10.3390/en14123634 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3634

Author(s):

Grzegorz Czerwiński ◽

Jerzy Wołoszyn

Keyword(s):

Mass Transfer ◽

Phase Change ◽

Heat Dissipation ◽

Cooling System ◽

Numerical Study ◽

Relaxation Parameter ◽

Phase Changes ◽

Transfer Time ◽

Two Phase ◽

Time Relaxation

With the increasing trend toward the miniaturization of electronic devices, the issue of heat dissipation becomes essential. The use of phase changes in a two-phase closed thermosyphon (TPCT) enables a significant reduction in the heat generated even at high temperatures. In this paper, we propose a modification of the evaporation–condensation model implemented in ANSYS Fluent. The modification was to manipulate the value of the mass transfer time relaxation parameter for evaporation and condensation. The developed model in the form of a UDF script allowed the introduction of additional source equations, and the obtained solution is compared with the results available in the literature. The variable value of the mass transfer time relaxation parameter during condensation rc depending on the density of the liquid and vapour phase was taken into account in the calculations. However, compared to previous numerical studies, more accurate modelling of the phase change phenomenon of the medium in the thermosyphon was possible by adopting a mass transfer time relaxation parameter during evaporation re = 1. The assumption of ten-fold higher values resulted in overestimated temperature values in all sections of the thermosyphon. Hence, the coefficient re should be selected individually depending on the case under study. A too large value may cause difficulties in obtaining the convergence of solutions, which, in the case of numerical grids with many elements (especially three-dimensional), significantly increases the computation time.

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Dependency of Machine Efficiency on the Thermal Behavior of Induction Machines

Machines ◽

10.3390/machines8010009 ◽

2020 ◽

Vol 8 (1) ◽

pp. 9

Author(s):

Svenja Kalt ◽

Karl Ludwig Stolle ◽

Philipp Neuhaus ◽

Thomas Herrmann ◽

Alexander Koch ◽

...

Keyword(s):

Thermal Behavior ◽

Electric Vehicles ◽

Thermal Load ◽

Load Capacity ◽

Maximum Load ◽

Induction Machines ◽

Electric Machines ◽

Model Parameters ◽

Dynamic Operating ◽

The Impact

The consideration of the thermal behavior of electric machines is becoming increasingly important in the machine design for electric vehicles due to the adaptation to more dynamic operating points compared to stationary applications. Whereas, the dependency of machine efficiency on thermal behavior is caused due to the impact of temperature on the resulting loss types. This leads to a shift of efficiency areas in the efficiency diagram of electric machines and has a significant impact on the maximum load capability and an impact on the cycle efficiency during operation, resulting in a reduction in the overall range of the electric vehicle. Therefore, this article aims at analyzing the thermal load limits of induction machines in regard to actual operation using measured driving data of battery electric vehicles. For this, a thermal model is implemented using MATLAB® and investigations to the sensitivity of model parameters as well as analysis of the continuous load capacity, thermal load and efficiency in driving cycles under changing boundary conditions are conducted.

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The Molecular Dynamics Study of Atomic Management and Thermal Behavior of Al-Water Nanofluid: A Two Phase Unsteady Simulation

Journal of Molecular Liquids ◽

10.1016/j.molliq.2021.117286 ◽

2021 ◽

pp. 117286

Author(s):

Yunhong Shi ◽

Seyedmahmoodreza allahyari ◽

S. Mohammad Sajadi ◽

Mashhour A. Alazwari ◽

Payam Firouzi ◽

...

Keyword(s):

Molecular Dynamics ◽

Thermal Behavior ◽

Two Phase ◽

Unsteady Simulation

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Boiling Enhanced Lidded Server Packages for Two-Phase Immersion Cooling Using 3D Metal Printing and Metal Injection Molding Technologies

Journal of Electronic Packaging ◽

10.1115/1.4052711 ◽

2021 ◽

Author(s):

Jimmy Chuang ◽

Jin Yang ◽

David Shia ◽

Y L Li

Keyword(s):

Injection Molding ◽

High Performance ◽

Heat Dissipation ◽

Thermal Design ◽

Metal Injection Molding ◽

Electronic Packages ◽

Two Phase ◽

Immersion Cooling ◽

Metal Printing ◽

3D Metal Printing

Abstract In order to meet increasing performance demand from high-performance computing (HPC) and edge computing, thermal design power (TDP) of CPU and GPU needs to increase. This creates thermal challenge to corresponding electronic packages with respect to heat dissipation. In order to address this challenge, two-phase immersion cooling is gaining attention as its primary mode of heat of removal is via liquid-to-vapor phase change, which can occur at relatively low and constant temperatures. In this paper, integrated heat spreader (IHS) with boiling enhancement features is proposed. 3D metal printing and metal injection molding (MIM) are the two approaches used to manufacture the new IHS. The resultant IHS with enhancement features are used to build test vehicles (TV) by following standard electronic package assembly process. Experimental results demonstrated that boiling enhanced TVs improved two-phase immersion cooling capability by over 50% as compared to baseline TV without boiling enhanced features.

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