Electronics Cooling System and Component Design According to the Second Law

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Ruben Gielen ◽  
Martine Baelmans
Keyword(s):  
Cooling System ◽  
Electronics Cooling ◽  
The Other ◽  
System Level ◽  
Second Law ◽  
Minimum Entropy ◽  
Component Level ◽  
Individual Level ◽  
Component Design ◽  
Minimum Entropy Generation

This work focuses on a comparison of second law based component design on one hand and second law based system design on the other within the context of electronics cooling. Typical electronics cooling components such as a heat sink and a heat exchanger are modeled and designed towards minimum entropy generation on individual level and on system level. A comparison of these levels allows us to qualify and quantify the influences among components induced by a system. Simultaneously, this article endeavors to be an illustrated assessment of the usefulness of efficiency criteria on component level. It turns out that the results of this work reveal a substantial influence of system dependencies on the optimal component design. As such a note of caution is raised about second law based component design which does not take into account the system in which a component has to operate.

Second-Law Analysis on Wavy Plate Fin-and-Tube Heat Exchangers

1998 ◽  
Vol 120 (3) ◽  
pp. 797-800 ◽  
Author(s):  
W. W. Lin ◽  
D. J. Lee
Keyword(s):  
Entropy Generation ◽  
Operating Conditions ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Second Law ◽  
Spanwise Direction ◽  
Minimum Entropy ◽  
Tube Heat Exchanger ◽  
Second Law Analysis ◽  
Minimum Entropy Generation

Second-law analysis on the herringbone wavy plate fin-and-tube heat exchanger was conducted on the basis of correlations of Nusselt number and friction factor proposed by Kim et al. (1997), from which the entropy generation rate was evaluated. Optimum Reynolds number and minimum entropy generation rate were found over different operating conditions. At a fixed heat duty, the in-line layout with a large tube spacing along streamwise direction was recommended. Furthermore, within the valid range of Kim et al.’s correlation, effects of the fin spacing and the tube spacing along spanwise direction on the second-law performance are insignificant.

scholarly journals The Second Law Today: Using Maximum-Minimum Entropy Generation

Entropy ◽  
2015 ◽  
Vol 17 (12) ◽  
pp. 7786-7797 ◽  
Author(s):  
Umberto Lucia ◽  
Giuseppe Grazzini
Keyword(s):  
Entropy Generation ◽  
Second Law ◽  
Minimum Entropy ◽  
Minimum Entropy Generation ◽  
Maximum Minimum

Thermal Control Strategies for Reliable and Energy-Efficient Data Centers

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Rehan Khalid ◽  
Aaron P. Wemhoff
Keyword(s):  
Data Center ◽  
Energy Efficient ◽  
Cooling System ◽  
System Level ◽  
Component Level ◽  
Simple Method ◽  
Control Schemes ◽  
Data Center Cooling ◽  
Efficient Data ◽  
The Impact

Two self-developed control schemes, ON/OFF and supervisory control and data acquisition (SCADA), were applied on a hybrid evaporative and direct expansion (DX)-based model data center cooling system to assess the impact of controls on reliability and energy efficiency. These control schemes can be applied independently or collectively, thereby saving the energy spent on mechanical refrigeration by using airside economization and/or evaporative cooling. Various combinations of system-level controls and component-level controls are compared to a baseline no-controls case. The results show that reliability is consistently met by employing only sophisticated component-level controls. However, the recommended conditions are met approximately 50% of the simulated time by employing system-level controls only (i.e., SCADA) but with a reduction in data center cooling system power usage effectiveness (PUE) values from 3.76 to 1.42. Moreover, the recommended conditions are met at all averaged times with an even lower cooling system PUE of 1.13 by combining system-level controls only (SCADA and ON/OFF controls). Thus, the study introduces a simple method to compare control schemes for reliable and energy-efficient data center operation. The work also highlights a potential source of capital expenses and operating expenses savings for data center owners by switching from expensive built-in component-based controls to inexpensive, yet effective, system-based controls that can easily be imbedded into existing data center infrastructure systems management.

Incorporating the Voice of the Customer in Preliminary Component Design

1999 ◽  
Author(s):  
Kurt A. Beiter ◽  
Kosuke Ishii
Keyword(s):  
System Level ◽  
Parameter Design ◽  
Operational Performance ◽  
Customer Requirements ◽  
Component Level ◽  
Component Design ◽  
Decision Variables ◽  
Independent Decision ◽  
The Voice ◽  
Voice Of The Customer

Abstract This paper describes a procedure for incorporating the voice of the customer into preliminary component design. The procedure begins with establishing the customer requirements, the engineering metrics, and their relation to the top-level subassemblies. Then, the approach establishes the component-level requirements through systematic engineering flow-down from the system level. Component-level manufacturing and operational performance models establish the link between independent decision variables and the component requirements. Thus a link is made between system level customer requirements and component parameter design. The paper uses the redesign of a computer video projector as an example.

scholarly journals Evaluating Model Uncertainty Based on Probabilistic Analysis and Component Output Uncertainty Descriptions

2012 ◽  
Author(s):  
Magnus Carlsson ◽  
Hampus Gavel ◽  
Johan Ölvander
Keyword(s):  
Cooling System ◽  
Measurement Data ◽  
Simulation Models ◽  
System Level ◽  
Upper And Lower Bounds ◽  
Early Model ◽  
Model Uncertainties ◽  
Component Level ◽  
Output Uncertainty ◽  
Model Components

To support early model validation, this paper describes a method utilizing information obtained from the common practice component level validation to assess uncertainties on model top level. Initiated in previous research, a generic output uncertainty description component, intended for power-port based simulation models of physical systems, has been implemented in Modelica. A set of model components has been extended with the generic output uncertainty description, and the concept of using component level output uncertainty to assess model top level uncertainty has been applied on a simulation model of a radar liquid cooling system. The focus of this paper is on investigating the applicability of combining the output uncertainty method with probabilistic techniques, not only to provide upper and lower bounds on model uncertainties but also to accompany the uncertainties with estimated probabilities. It is shown that the method may result in a significant improvement in the conditions for conducting an assessment of model uncertainties. The primary use of the method, in combination with either deterministic or probabilistic techniques, is in the early development phases when system level measurement data are scarce. The method may also be used to point out which model components contribute most to the uncertainty on model top level. Such information can be used to concentrate physical testing activities to areas where it is needed most. In this context, the method supports the concept of Virtual Testing.

Dynamic Infrared System Level Fault Isolation

2003 ◽  
Author(s):  
John A. Naoum ◽  
Johan Rahardjo ◽  
Yitages Taffese ◽  
Marie Chagny ◽  
Jeff Birdsley ◽  
...  
Keyword(s):  
Fault Isolation ◽  
System Level ◽  
System Component ◽  
Component Level ◽  
Ir Imaging ◽  
Non Destructive

Abstract The use of Dynamic Infrared (IR) Imaging is presented as a novel, valuable and non-destructive approach for the analysis and isolation of failures at a system/component level.

scholarly journals System models for resilience in gerontology: application to the COVID-19 pandemic

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Katarzyna Klasa ◽  
Stephanie Galaitsi ◽  
Andrew Wister ◽  
Igor Linkov
Keyword(s):  
The Elderly ◽  
System Level ◽  
Improve Quality ◽  
Care Needs ◽  
Individual Level ◽  
Chronic Stressors ◽  
The World ◽  
Aging Adults ◽  
The Individual

AbstractThe care needs for aging adults are increasing burdens on health systems around the world. Efforts minimizing risk to improve quality of life and aging have proven moderately successful, but acute shocks and chronic stressors to an individual’s systemic physical and cognitive functions may accelerate their inevitable degradations. A framework for resilience to the challenges associated with aging is required to complement on-going risk reduction policies, programs and interventions. Studies measuring resilience among the elderly at the individual level have not produced a standard methodology. Moreover, resilience measurements need to incorporate external structural and system-level factors that determine the resources that adults can access while recovering from aging-related adversities. We use the National Academies of Science conceptualization of resilience for natural disasters to frame resilience for aging adults. This enables development of a generalized theory of resilience for different individual and structural contexts and populations, including a specific application to the COVID-19 pandemic.

System Level Bench Test for Trailing Arm Strength Estimation

2006 ◽  
Author(s):  
Jaychandar Muthu ◽  
Kanak Soundrapandian ◽  
Jyoti Mukherjee
Keyword(s):  
Failure Mode ◽  
Real Life ◽  
Element Model ◽  
Suspension System ◽  
System Level ◽  
Bench Test ◽  
Component Level ◽  
Arm Strength ◽  
Bench Testing ◽  
Nonlinear Finite Element Model

For suspension components, bench testing for strength is mostly accomplished at component level. However, replicating loading and boundary conditions at the component level in order to simulate the suspension system environment may be difficult. Because of this, the component's bench test failure mode may not be similar to its real life failure mode in vehicle environment. A suspension system level bench test eliminates most of the discrepancies between simulated component level and real life vehicle level environments resulting in higher quality bench tests yielding realistic test results. Here, a suspension level bench test to estimate the strength of its trailing arm link is presented. A suspension system level nonlinear finite element model was built and analyzed using ABAQUS software. The strength loading was applied at the wheel end. The analysis results along with the hardware test correlations are presented. The reasons why a system level test is superior to a component level one are also highlighted.

scholarly journals Emergence of cultural intelligence and global mindset capital: a multilevel model

2016 ◽  
Vol 24 (2) ◽  
pp. 106-122 ◽  
Author(s):  
Jase R. Ramsey ◽  
Amine Abi Aad ◽  
Chuandi Jiang ◽  
Livia Barakat ◽  
Virginia Drummond
Keyword(s):  
Multilevel Model ◽  
Cultural Intelligence ◽  
The Other ◽  
Global Mindset ◽  
Firm Level ◽  
Content Type ◽  
Individual Level ◽  
Other Hand ◽  
Underlying Mechanisms ◽  
Conceptual Study

Purpose The purpose of this paper is to establish under which conditions researchers should use the constructs cultural intelligence (CQ) and global mindset (GM). The authors further seek to understand the process through which these constructs emerge to a higher level and link unit-level knowledge, skills and abilities (KSAs) capital to pertinent firm-level outcomes. Design/methodology/approach This paper is a conceptual study with a multilevel model. Findings This paper differentiates two similar lines of research occurring concordantly on the CQ and GM constructs. Next, the authors develop a multilevel model to better understand the process through which CQ and GM emerge at higher levels and their underlying mechanisms. Finally, this paper adds meaning to the firm-level KSAs by linking firm-level KSAs capital to pertinent firm-level outcomes. Research limitations/implications The conclusion implies that researchers should use CQ when the context is focused on interpersonal outcomes and GM when focused on strategic outcomes. The multilevel model is a useful tool for scholars to select which rubric to use in future studies that have international managers as the subjects. The authors argue that if the scholar is interested in an individual’s ability to craft policy and implement strategy, then GM may be more parsimonious than CQ. On the other hand, if the focus is on leadership, human resources or any other relationship dependent outcome, then CQ will provide a more robust measure. Practical implications For practitioners, this study provides a useful tool for managers to improve individual-level commitment by selecting and training individuals high in CQ. On the other hand, if the desired outcome is firm-level sales or performance, the focus should be on targeting individuals high in GM. Originality/value This is the first theoretical paper to examine how CQ and GM emerge to the firm level and describe when to use each measure.

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