Thermal Management Solutions for Network File Server Used in Avionics Applications

2014 ◽  
Vol 2014 (1) ◽  
pp. 000419-000427
Author(s):  
Vicentiu Grosu ◽  
Chris Lindgren ◽  
Tamas Vejsz ◽  
Ya-Chi Chen ◽  
Avijit Bhunia
Keyword(s):  
Thermal Management ◽  
Airflow Rate ◽  
Confined Space ◽  
File Server ◽  
Network Systems ◽  
Commercial Aviation ◽  
Design And Optimization ◽  
Critical Components ◽  
Passive Cooling Systems ◽  
Cooling Air

In the modern era of commercial aviation there is an increasing need for establishing on-aircraft networks that interconnect legacy avionics systems for the purpose of data collection, health monitoring, and software management. At the heart of these networks are flightworthy file servers that perform similar functions to servers used in ground-based IT infrastructures. However, the size, weight, and power constraints for airborne servers are significantly more challenging than the constraints placed on groundbased equipment. As a result, the critical goals in the development of aircraft network systems are reducing the size and weight, maximizing the performance and reliability, and reducing cost. One of the main challenges includes dissipating high power in small packages within a confined space. This makes thermal management a critical component of the overall LRU (Line-Replaceable Unit) design. In addition, passive cooling systems are often required in place of internal fans in order to improve long-term reliability of the system. This presents another set of challenges, such as optimizing the airflow provided by the aircraft in the electronics compartment. This paper will present some of the critical elements of thermal management such as heat sinking, component placement, thermal interface materials, thermal vias, thermal links, heat spreader, packaging approaches and cooling strategies. The design and optimization of this system are based on analytical solutions, conjugated heat transfer and experimental results. Thermal management solutions must enable reliable operation under various environmental conditions: ground operation, flight operation, high operating temperature and loss of cooling air. Each environmental condition has different parameters for coolant airflow rate, effect of the surroundings, and ambient and coolant air temperature. Cooling airflow analyses were performed using CFD (Computational Fluid Dynamics). We have identified multiple approaches to remove heat from the critical components through optimization of the components and subsystems. These same approaches also serve to increase the system's performance and reliability.

Thermal Management Solutions for enhanced Digital Flight Data Acquisition Unit in Avionics Applications

2015 ◽  
Vol 2015 (1) ◽  
pp. 000517-000525
Author(s):  
Vicentiu Grosu ◽  
Chris Lindgren ◽  
Tamas Vejsz
Keyword(s):  
Heat Transfer ◽  
Data Acquisition ◽  
Thermal Management ◽  
Airline Industry ◽  
Airflow Rate ◽  
Confined Space ◽  
Flight Data ◽  
Conjugated Heat Transfer ◽  
Data Acquisition Unit ◽  
New Generation

According to the Federal Aviation Administration, the commercial airline industry should expect to see the number of passengers traveling per year to grow from its current level of 750 million to nearly 1 billion by 2030. To meet this demand, airlines are placing orders for thousands of new aircraft over the next decade and beyond. With this increase in airline traffic, newer aircraft systems will generate an ever increasing amount of data per flight, data that allows airlines to further enhance their flight operations, flight safety, and reliability. For commercial avionics, the migration of the data acquisition and reporting functions from the traditional interface environments to newer, faster, and more network-centric architectures is creating a new generation of “smart” aircraft. Teledyne Controls' enhanced Digital Flight Data Acquisition Unit is an integral part of a new generation of aircraft and combines the functions of Mandatory Data Acquisition and Recording with a sophisticated Aircraft Conditioning Monitoring System that the aircraft operator uses to monitor the performance and reliability of each aircraft in its fleet. Some of the critical goals in the development of the Digital Flight Data Acquisition Unit are reducing the size and weight over previous generations, while maximizing performance and reducing cost. All of these opposing requirements make the design and fabrication very challenging. One such challenge includes dissipating high power in a confined space, and this makes thermal management a critical component of the overall LRU (line-replaceable unit) design. In addition, to increase the reliability over the lifespan of the unit, passive cooling systems are often required in place of internal fans. This presents another set of challenges, such as optimizing the airflow provided by the aircraft in the electronics bay compartment. This paper will present some of the critical elements in thermal management such as heat sinks, components placement, thermal interface materials, thermal vias, thermal links, packaging approaches and cooling strategy. The design and optimization of the system are based on analytical solutions, conjugated heat transfer and experimental results. The LRU should safely operate under various environmental conditions: ground operation, flight operation, high operating temperature and loss of cooling air where each environmental condition has different parameters for coolant airflow rate, effect of the surroundings, and ambient and coolant air temperature. Draw-Through and Blow-Through cooling analysis were performed using CFD (Computational Fluid Dynamics). The thermal analysis problems solved are conjugated heat transfer for laminar flow with radiation in steady-state or transient regimes. Multiple approaches were identified to remove heat from the critical components through optimization of the components and subsystems. These same approaches can also be used to increase the system's performance and reliability.

scholarly journals Models to inform neutralizing antibody therapy strategies during pandemics: the case of SARS-CoV-2

2021 ◽  
Vol 4 (1) ◽  
pp. 60-71
Author(s):  
Donovan Guttieres ◽  
Anthony J Sinskey ◽  
Stacy L Springs
Keyword(s):  
Value Chain ◽  
Neutralizing Antibodies ◽  
Resource Constraints ◽  
Antibody Therapy ◽  
Neutralizing Antibody ◽  
Epidemiological Data ◽  
Production Costs ◽  
Production Scale ◽  
Design And Optimization ◽  
Critical Components

Abstract Background Neutralizing antibodies (nAbs) against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) can play an important role in reducing impacts of the COVID-19 pandemic, complementing ongoing public health efforts such as diagnostics and vaccination. Rapidly designing, manufacturing and distributing nAbs requires significant planning across the product value chain and an understanding of the opportunities, challenges and risks throughout. Methods A systems framework comprised of four critical components is presented to aid in developing effective end-to-end nAbs strategies in the context of a pandemic: (1) product design and optimization, (2) epidemiology, (3) demand and (4) supply. Quantitative models are used to estimate product demand using available epidemiological data, simulate biomanufacturing operations from typical bioprocess parameters and calculate antibody production costs to meet clinical needs under various realistic scenarios. Results In a US-based case study during the 9-month period from March 15 to December 15, 2020, the projected number of SARS-CoV-2 infections was 15.73 million. The estimated product volume needed to meet therapeutic demand for the maximum number of clinically eligible patients ranged between 6.3 and 31.5 tons for 0.5 and 2.5 g dose sizes, respectively. The relative production scale and cost needed to meet demand are calculated for different centralized and distributed manufacturing scenarios. Conclusions Meeting demand for anti-SARS-CoV-2 nAbs requires significant manufacturing capacity and planning for appropriate administration in clinical settings. MIT Center for Biomedical Innovation’s data-driven tools presented can help inform time-critical decisions by providing insight into important operational and policy considerations for making nAbs broadly accessible, while considering time and resource constraints.

Perimeter Cooling Unit and Localized Row-Based Cooling Unit Transient Air Flow Effects Modeling and Characterization in Data Centers

2015 ◽  
Author(s):  
Tianyi Gao ◽  
James Geer ◽  
Bahgat G. Sammakia ◽  
Russell Tipton ◽  
Mark Seymour
Keyword(s):  
Thermal Management ◽  
Data Center ◽  
Data Centers ◽  
Cooling System ◽  
Air Flow ◽  
Cooling Systems ◽  
Dynamic Thermal Management ◽  
Hybrid Cooling ◽  
Cooling Unit ◽  
Cooling Air

Cooling power constitutes a large portion of the total electrical power consumption in data centers. Approximately 25%∼40% of the electricity used within a production data center is consumed by the cooling system. Improving the cooling energy efficiency has attracted a great deal of research attention. Many strategies have been proposed for cutting the data center energy costs. One of the effective strategies for increasing the cooling efficiency is using dynamic thermal management. Another effective strategy is placing cooling devices (heat exchangers) closer to the source of heat. This is the basic design principle of many hybrid cooling systems and liquid cooling systems for data centers. Dynamic thermal management of data centers is a huge challenge, due to the fact that data centers are operated under complex dynamic conditions, even during normal operating conditions. In addition, hybrid cooling systems for data centers introduce additional localized cooling devices, such as in row cooling units and overhead coolers, which significantly increase the complexity of dynamic thermal management. Therefore, it is of paramount importance to characterize the dynamic responses of data centers under variations from different cooling units, such as cooling air flow rate variations. In this study, a detailed computational analysis of an in row cooler based hybrid cooled data center is conducted using a commercially available computational fluid dynamics (CFD) code. A representative CFD model for a raised floor data center with cold aisle-hot aisle arrangement fashion is developed. The hybrid cooling system is designed using perimeter CRAH units and localized in row cooling units. The CRAH unit supplies centralized cooling air to the under floor plenum, and the cooling air enters the cold aisle through perforated tiles. The in row cooling unit is located on the raised floor between the server racks. It supplies the cooling air directly to the cold aisle, and intakes hot air from the back of the racks (hot aisle). Therefore, two different cooling air sources are supplied to the cold aisle, but the ways they are delivered to the cold aisle are different. Several modeling cases are designed to study the transient effects of variations in the flow rates of the two cooling air sources. The server power and the cooling air flow variation combination scenarios are also modeled and studied. The detailed impacts of each modeling case on the rack inlet air temperature and cold aisle air flow distribution are studied. The results presented in this work provide an understanding of the effects of air flow variations on the thermal performance of data centers. The results and corresponding analysis is used for improving the running efficiency of this type of raised floor hybrid data centers using CRAH and IRC units.

Analysis of Thermal Properties of Power Multifinger HEMT Devices

2018 ◽  
Author(s):  
Aleš Chvála ◽  
Robert Szobolovszký ◽  
Jaroslav Kováč ◽  
Martin Florovič ◽  
Juraj Marek ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Thermal Management ◽  
High Electron Mobility Transistor ◽  
Structure Design ◽  
High Electron ◽  
Design And Optimization ◽  
Chip Temperature ◽  
Materials Used ◽  
On Chip ◽  
Measurement Approach

In this paper, several methods suitable for real time on-chip temperature measurements of power AlGaN/GaN based high-electron mobility transistor (HEMT) grown on SiC substrate are presented. The measurement of temperature distribution on HEMT surface using Raman spectroscopy is presented. We have deployed a temperature measurement approach utilizing electrical I-V characteristics of the neighboring Schottky diode under different dissipated power of the transistor heat source. These methods are verified by measurements with micro thermistors. The results show that these methods have a potential for HEMT analysis in thermal management. The features and limitations of the proposed methods are discussed. The thermal parameters of materials used in the device are extracted from temperature distribution in the structure with the support of 3-D device thermal simulation. The thermal analysis of the multifinger power HEMT is performed. The effects of the structure design and fabrication processes from semiconductor layers, metallization, and packaging up to cooling solutions are investigated. The analysis of thermal behavior can help during design and optimization of power HEMT.

Three-Dimensional Single Particle Tracking and Its Applications in Confined Environments

2020 ◽  
Vol 13 (1) ◽  
pp. 381-403
Author(s):  
Yaning Zhong ◽  
Gufeng Wang
Keyword(s):  
Mass Transport ◽  
Particle Tracking ◽  
Single Particle ◽  
Three Dimensional ◽  
Surface Interactions ◽  
Single Particle Tracking ◽  
Confined Space ◽  
Design And Optimization ◽  
Chemical Recognition ◽  
Molecule Surface

Single particle tracking (SPT) has proven to be a powerful technique in studying molecular dynamics in complicated systems. We review its recent development, including three-dimensional (3D) SPT and its applications in probing nanostructures and molecule-surface interactions that are important to analytical chemical processes. Several frequently used 3D SPT techniques are introduced. Especially of interest are those based on point spread function engineering, which are simple in instrumentation and can be easily adapted and used in analytical labs. Corresponding data analysis methods are briefly discussed. We present several important case studies, with a focus on probing mass transport and molecule-surface interactions in confined environments. The presented studies demonstrate the great potential of 3D SPT for understanding fundamental phenomena in confined space, which will enable us to predict basic principles involved in chemical recognition, separation, and analysis, and to optimize mass transport and responses by structural design and optimization.

Heat Transfer Analysis in a Modern DLN Combustor

2000 ◽  
Author(s):  
Giovanni Ferrara ◽  
Luca Innocenti ◽  
Giacomo Migliorini ◽  
Bruno Facchini ◽  
Anthony J. Dean
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Film Cooling ◽  
Thermal Flux ◽  
Calculation Model ◽  
Heat Transfer Analysis ◽  
Turbine Blade Cooling ◽  
Air Flows ◽  
Critical Components ◽  
Cooling Air

The increasingly stringent emissions standards in recent years have mandated low gas turbine emissions and thus changed the approach to combustion chamber design. In particular, lean burners based on highly premixed fuel-air flows have become more important. These combustors, termed Dry Low NOx (DLN), can now achieve emissions of 25 ppm and below in commercial operation. This development together with the inlet turbine temperature increase has resulted in less cooling air for combustion chambers and turbine blade cooling systems. The designer now needs to optimise cooling air flows that control the wall temperature of the components that confine the hot gases. Moreover, much of the air coming from the compressor is used to premix the fuel and only a smaller fraction is now available for cooling processes. In annular combustor configurations the air available for cooling the combustion chamber walls sometimes also has to cool the first stage nozzle. So the pressure loss along the combustor cooling passages has to be limited in order to assure a suitable supply pressure for these downstream cooling passages. We analysed the cooling air flow around the liner of an annular combustion chamber and we investigated the thermal flux and friction losses. In this paper we show the development of a calculation model that allows the critical components heat transfer analysis of a typical annular combustion chamber. The code developed is based on the generalised 1–D flow treatment. We have used experimental correlations for convection, film cooling and impingement borrowed from works found in literature. The code is provided with a graphical interface that helps the user during the calculation. This code was used in practical application to optimize the PGT5B combustion chamber cooling.

Air Flow Velocity Field Validation and Turbulence Studies on a Single Rack Model in Data Centers

2018 ◽  
Author(s):  
Long Phan ◽  
Beichao Hu ◽  
Cheng-Xian Lin
Keyword(s):  
Thermal Management ◽  
Large Scale ◽  
Data Centers ◽  
Turbulence Models ◽  
Airflow Rate ◽  
Cold Air ◽  
Large Scale Data ◽  
Air Supply ◽  
Equipment Failures ◽  
Air Flow Velocity

Due to the rapid growth in IT demands over the past few decades, the market for data centers also increases dramatically. However, thermal management remains a big issue in the design of large-scale data centers. Although best practices are deployed to utilize perforated tiles together with the hot and cold aisles configuration to improve the thermal management, thermal hotspots are inevitable in IT racks, which causes equipment failures and signal interruptions. Thermal hotspots in air-cooled data centers are due to many factors such as insufficient cold air supply from the raised-floor plenum, air recirculation from hot aisle into cold aisle, airflow non-uniformity at the perforated tiles, etc. One of the ways to mitigate such issues is to uniformly distribute the cold air by properly controlling the airflow rate through perforated tiles. In this study, a validation study of the tile airflow and the rack airflow rate ratio of 20% is carried out using an adopted tile model. Also, several turbulence models are thoroughly investigated, and recommendations are provided for the most accurate and less time-consuming turbulence model when applying to a single rack model.

scholarly journals Experimental Investigation on a Thermoelectric Cooler for Thermal Management of a Lithium-Ion Battery Module

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Xinxi Li ◽  
Zhaoda Zhong ◽  
Jinghai Luo ◽  
Ziyuan Wang ◽  
Weizhong Yuan ◽  
...  
Keyword(s):  
Thermal Management ◽  
Cooling System ◽  
Discharge Rate ◽  
Lithium Ion ◽  
Design And Optimization ◽  
System A ◽  
Battery Thermal Management ◽  
Thermal Management System ◽  
Battery Thermal Management System ◽  
Battery Module

Electric vehicles (EVs) powered by lithium batteries, which are a promising type of green transportation, have attracted much attention in recent years. In this study, a thermoelectric generator (TEG) coupled with forced convection (F-C) was designed as an effective and feasible cooling system for a battery thermal management system. A comparison of natural convection cooling, F-C cooling, and TEG cooling reveals that the TEG is the best cooling system. Specifically, this system can decrease the temperature by 16.44% at the discharge rate of 3C. The coupled TEG and F-C cooling system can significantly control temperature at a relatively high discharge rate. This system not only can decrease the temperature of the battery module promptly but also can reduce the energy consumption compared with the two other TEG-based cooling systems. These results are expected to supply an effective basis of the design and optimization of battery thermal management systems to improve the reliability and safety performance of EVs.

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