scholarly journals CFD Optimization of the Cooling of Yosemite Open Compute Server

2017 ◽  
Author(s):  
Aditya Gupta ◽  
Ananthavijayan Sridhar ◽  
Dereje Agonafer
Keyword(s):  
Energy Consumption ◽  
Data Centers ◽  
Air Flow ◽  
Flow Characteristics ◽  
Cost Savings ◽  
Cooling Power ◽  
Original Design ◽  
Flow Optimization ◽  
Cooling Performance ◽  
The Impact

Over the past few years, there has been an ever increasing rise in energy consumption by IT equipment in Data Centers. Thus, the need to minimize the environmental impact of Data Centers by optimizing energy consumption and material use is increasing. In 2011, the Open Compute Project was started which was aimed at sharing specifications and best practices with the community for highly energy efficient and economical data centers. The first Open Compute Server was the ‘ Freedom’ Server. It was a vanity free design and was completely custom designed using minimum number of components and was deployed in a data center in Prineville, Oregon. Within the first few months of operation, considerable amount of energy and cost savings were observed. Since then, progressive generations of Open Compute servers have been introduced. Initially, the servers used for compute purposes mainly had a 2 socket architecture. In 2015, the Yosemite Open Compute Server was introduced which was suited for higher compute capacity. Yosemite has a system on a chip architecture having four CPUs per sled providing a significant improvement in performance per watt over the previous generations. This study mainly focuses on air flow optimization in Yosemite platform to improve its overall cooling performance. Commercially available CFD tools have made it possible to do the thermal modeling of these servers and predict their efficiency. A detailed server model is generated using a CFD tool and its optimization has been done to improve the air flow characteristics in the server. Thermal model of the improved design is compared to the existing design to show the impact of air flow optimization on flow rates and flow speeds which in turn affects CPU die temperatures and cooling power consumption and thus, impacting the overall cooling performance of the Yosemite platform. Emphasis is given on effective utilization of fans in the server as compared to the original design and improving air flow characteristics inside the server via improved ducting.

Data Center Cooling Efficiency Improvement Through Localized and Optimized Cooling Resources Delivery

2012 ◽  
Author(s):  
Rongliang Zhou ◽  
Cullen Bash ◽  
Zhikui Wang ◽  
Alan McReynolds ◽  
Thomas Christian ◽  
...  
Keyword(s):  
Steady State ◽  
Data Center ◽  
Data Centers ◽  
Air Flow ◽  
Flow Distribution ◽  
Resource Provisioning ◽  
Cooling Power ◽  
Optimization Approach ◽  
Cooling Efficiency ◽  
Efficiency Improvement

Data centers are large computing facilities that can house tens of thousands of computer servers, storage and networking devices. They can consume megawatts of power and, as a result, reject megawatts of heat. For more than a decade, researchers have been investigating methods to improve the efficiency by which these facilities are cooled. One of the key challenges to maintain highly efficient cooling is to provide on demand cooling resources to each server rack, which may vary with time and rack location within the larger data center. In common practice today, chilled water or refrigerant cooled computer room air conditioning (CRAC) units are used to reject the waste heat outside the data center, and they also work together with the fans in the IT equipment to circulate air within the data center for heat transport. In a raised floor data center, the cool air exiting the multiple CRAC units enters the underfloor plenum before it is distributed through the vent tiles in the cold aisles to the IT equipment. The vent tiles usually have fixed openings and are not adapted to accommodate the flow demand that can vary from cold aisle to cold aisle or rack to rack. In this configuration, CRAC units have the extra responsibilities of cooling resources distribution as well as provisioning. The CRAC unit, however, does not have the fine control granularity to adjust air delivery to individual racks since it normally affects a larger thermal zone, which consists of a multiplicity of racks arranged into rows. To better match cool air demand on a per cold aisle or rack basis, floor-mounted adaptive vent tiles (AVT) can be used to replace CRAC units for air delivery adjustment. In this arrangement, each adaptive vent tile can be remotely commanded from fully open to fully close for finer local air flow regulation. The optimal configuration for a multitude of AVTs in a data center, however, can be far from intuitive because of the air flow complexity. To unleash the full potential of the AVTs for improved air flow distribution and hence higher cooling efficiency, we propose a two-step approach that involves both steady-state and dynamic optimization to optimize the cooling resource provisioning and distribution within raised-floor air cooled data centers with rigid or partial containment. We first perform a model-based steady-state optimization to optimize whole data center air flow distribution. Within each cold aisle, all AVTs are configured to a uniform opening setting, although AVT opening may vary from cold aisle to cold aisle. We then use decentralized dynamic controllers to optimize the settings of each CRAC unit such that the IT equipment thermal requirement is satisfied with the least cooling power. This two-step optimization approach simplifies the large scale dynamic control problem, and its effectiveness in cooling efficiency improvement is demonstrated through experiments in a research data center.

scholarly journals The Energy Consumption Aspects in the Vacuum Assisted Moulding Process/ Aspekty Energochłonności W Procesie Formowania Podciśnieniowego

2014 ◽  
Vol 59 (4) ◽  
pp. 1331-1336 ◽  
Author(s):  
K. Smyksy ◽  
M. Brzezinski
Keyword(s):  
Energy Consumption ◽  
Air Flow ◽  
Test Stand ◽  
Original Design ◽  
Compaction Process ◽  
Foundry Sand ◽  
Moulding Process ◽  
Optimal Methods ◽  
Moulding Sand

Abstract In the current manufacturing of foundry sand moulds, various methods of moulding sand compaction are used. Researchers are still looking for the optimal methods of mould manufacturing not only in terms of achieving the best technological effects, but also in terms of energy consumption. The article presents selected results of research of their own variant of the synthetic moulding sand compaction process using a vacuum. The measurements were also designed for evaluation the energy consumption in this method. The results were compared with other air flow moulding methods which are widely used. The study was performed on the original design test stand, which allows the visualization of the compaction process

Comparative Analysis of Different In Row Cooler Management Configurations in a Hybrid Cooling Data Center

2015 ◽  
Author(s):  
Tianyi Gao ◽  
Bahgat G. Sammakia ◽  
James Geer ◽  
Bruce Murray ◽  
Russell Tipton ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Data Center ◽  
Power Plants ◽  
Data Centers ◽  
Electricity Consumption ◽  
Design Guidelines ◽  
Cooling Systems ◽  
Density Data ◽  
Hybrid Cooling ◽  
The Impact

The heat dissipated by electronic equipment inside data centers is increasing at a rapid rate due to the increasing of performance requirement and package density. This ever increasing power leads to critical challenges of thermal management for these high power density data centers. Energy consumption is also a key issue for high density data centers. Roughly 1.5% of all U.S. electricity consumption in the year 2006 was related to data centers, while that number increased to 2% by the year 2010. In 2013, U.S. data centers consumed approximately 91 billion kilowatt-hours of electricity. This amount of the electricity equals the annual output of 34 500-megawatt coal-fired power plants [1]. Cooling systems constitute a significant portion of the energy consumption of data centers, being approximately 25%∼35% of the total energy usage. Therefore, there is a large potential to save energy by optimizing current existing cooling systems and investigating new cooling technologies, and, at the same time, improving the overall cooling capacity and efficiency. This paper describes and investigates a hybrid cooling technology which utilizes in row coolers in existing raised floor air cooled data centers. The in row cooler functions as a liquid-to-air heat exchanger. In addition to the traditional raised floor cold aisle-hot aisle arrangements, the in row cooler is installed between the IT equipment to enable delivering the liquid coolant medium closer to the IT equipment. The in row coolers intake the hot air from the hot aisle, condition it, and supply the chilled air to the cold aisle. Thus, by extracting a large portion of the heat more directly into the cooling liquid through the in row coolers compared with the perimeter CRAH unit, the overall cooling performance and efficiency can potentially be improved. CFD models for an in row cooler and a representative data center room are developed. Experimentally characterized performance data are used to calibrate and validate the models. The models are then used to conduct a detailed computational analysis to assess the effectiveness of different arrangement configurations of in row cooler units in two rows of racks along one cold aisle. The detailed performance of the entire cold aisle is characterized using the rack inlet air temperature and a temperature nonuniformity factor. The impact of CRAH location and room layout are also investigated. This study is based on a practical problem and the corresponding results and analysis provide basic installation and design guidelines for future equipment upgrading in certain parts of the data center.

Analysis of the impact of a novel cool roof on cooling performance for a low-rise prefabricated building in China

2020 ◽  
Vol 42 (1) ◽  
pp. 26-44
Author(s):  
Mingquan Ma ◽  
Kai Zhang ◽  
Lufang Chen ◽  
Saihong Tang
Keyword(s):  
Energy Saving ◽  
Cooling Power ◽  
Radiative Cooling ◽  
Climate Zones ◽  
Cooling Performance ◽  
Cool Roof ◽  
Energy Saving Potential ◽  
Good Energy ◽  
The Impact ◽  
Prefabricated Building

The recently proposed scalable-manufactured randomized glass-polymer hybrid metamaterial (i.e. metamaterial film) exhibits good energy-saving potential for building applications. The most convenient way to employ this metamaterial film-based radiative cooling is to integrate it with buildings as cool roofs. However, metamaterial film-based radiative cooling is more suitable for buildings with higher roof area to floor area ratios, as this accounts for its relative lower cooling power of 110 W/m2 on a daily average. The prefabricated buildings in China are commonly less than two floors, which are preferable for the application of this metamaterial film-based radiative cooling. To clearly reveal the cooling performance of the metamaterial film-based cool roof (MFCR), a single-floor prefabricated building is modelled in this study, and the energy-saving potential and economic feasibility of the application of the MFCR on the prefabricated building are discussed in detail. When comparing the model in this study with buildings that have the more commonly used shingle roofs or typical white roofs, the annual cooling electricity consumption is reduced by 28.9%–43.0% and 7.8%–12.9%, respectively, for buildings with MFCRs located in five cities in China, each in a different climate zone. Furthermore, the simple payback period for the buildings with MFCRs located in all five climate zones is less than three years compared to the buildings with shingle roofs. Practical application: A recently proposed metamaterial film exhibits good energy-saving potential for building applications. This paper explores the application of this metamaterial film as a cool roof on a low-rise prefabricated building. The analysis of the cooling performance and economic value of this low-rise prefabricated building located in all five climate zones in China provides guiding significance for the application of MFCR.

Lifetime Exergy Consumption as a Sustainability Metric for Enterprise Servers

2008 ◽  
Author(s):  
Christopher R. Hannemann ◽  
Van P. Carey ◽  
Amip J. Shah ◽  
Chandrakant Patel
Keyword(s):  
Data Centers ◽  
Large Data ◽  
Cooling Power ◽  
Processing Power ◽  
Dynamic Cooling ◽  
Exergy Consumption ◽  
Consumption Model ◽  
Processing And Storage ◽  
The Impact ◽  
And Storage

As the use of information technology becomes more ubiquitous, the need for data processing and storage capabilities increases. This results in the construction and operation of large data centers—facilities that house thousands of servers and serve as the backbone for all types of computational processes. Unfortunately, as processing power and storage capacity increases, so does the corresponding power and cooling requirements of the data centers. Several studies have examined the efficiency of data centers by focusing on server and cooling power inputs, but this fails to capture the data center’s entire impact. To accomplish this, the use of a lifetime exergy (available energy) analysis is proposed. This study first details the development of a lifetime exergy consumption model designed specifically for data center analysis. To create a database of computer components, a disassembly analysis was performed, and the results are detailed. By combining the disassembly analysis of a server with the aggregation of energy and material data, a more rigorous and useful assessment of the server’s overall impact is demonstrated. The operation of the lifetime exergy consumption model is demonstrated by case studies examining the effects of variance in transportation and cooling strategies. The importance of transportation modes and material mass, which are greatly affected by supply chain parameters, is shown. The impact of static and dynamic cooling within data centers is also demonstrated.

scholarly journals Reducing The Energy Consumption By Using Floor Heating With Phase Change Materials In The Toronto Climate

2021 ◽  
Author(s):  
Lindsay Fialkov
Keyword(s):  
Energy Consumption ◽  
Phase Change ◽  
Phase Change Materials ◽  
Energy Savings ◽  
Cost Savings ◽  
Heating System ◽  
Radiant Floor Heating System ◽  
The Cost ◽  
The Impact ◽  
Floor Heating

This major research project focuses on reducing the energy consumption, by modelling a radiant floor heating system with phase change materials, in the Toronto climate. Computer generated simulations were performed using DesignBuilder software, using an example of a typical condominium in Toronto .Two south facing suites and two north facing suites were investigated. Of those suites, one north facing suite had PCM below the finished floor, as well as one south facing suite. The objective of these simulations was to determine the impact of using PCM in the condo suites. Three different types of PCM were used, in order to determine which type had the biggest energy savings. The PCMs were M91/Q21, M51/Q21 and M27/Q21. The final results showed that the suites with the M27/Q21 PCM had the lowest energy usage. A cost savings comparison was performed based on the rate of energy used and the cost of the energy, provided by the Ontario Energy Board.

scholarly journals Building energy simulations for different building types equipped with a high performance thermochromic smart window

2021 ◽  
Vol 855 (1) ◽  
pp. 012001
Author(s):  
D Mann ◽  
C Yeung ◽  
R Habets ◽  
Z Vroon ◽  
P Buskens
Keyword(s):  
Energy Consumption ◽  
Annual Cost ◽  
High Performance ◽  
Energy Savings ◽  
Cost Savings ◽  
Residential Building ◽  
Building Energy ◽  
Smart Window ◽  
Smart Windows ◽  
The Impact

Abstract With constantly progressing climate change and global warming, we face the challenge to reduce our energy consumption and CO2 emission. To increase the energy-efficiency in buildings, we developed a thermochromic coating for smart windows which is optimized for intermediate climates. Here we present a building energy simulation study for the use of our smart window in the four main residential building types in the Netherlands. In the study we show that for all building types energy savings between 15-30% can be achieved. Hereby the impact of the windows on energy consumption is dependent on the window surface area as well as the total floor space. Furthermore we show that by the use of our new smart window, where the thermochromic coating is combined with a standard low-e coating, annual cost savings for energy between 220-445 € for a single household can be achieved. The thermochromic coating usually accounts for half of these cost savings, that is an addition in cost savings between 6-7.5 €/m2 glass. Due to the low material and processing costs for the thermochromic coating, a return on invest within 7 years should be feasible with these annual cost savings.

scholarly journals Aerodynamic Characteristics of Isolated Loaded Tires with Different Tread Patterns: Experiment and Simulation

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Haichao Zhou ◽  
Zhen Jiang ◽  
Guolin Wang ◽  
Shupei Zhang
Keyword(s):  
Flow Field ◽  
Aerodynamic Drag ◽  
Flow Direction ◽  
Air Flow ◽  
Flow Characteristics ◽  
Aerodynamic Characteristics ◽  
Test Model ◽  
Pressure Coefficients ◽  
Pressure Area ◽  
The Impact

AbstractThe current research of tire aerodynamics mainly focus on the isolated and simplified tread tire. Compared with the real complex pattern tire, the tread pattern structure and deformed profile of a loaded tire has a greatly influence on tire aerodynamic drag. However, the mechanisms of the isolated loaded tires with different tread patterns effects on the aerodynamic drag are subjects worthy of discussion. The purpose of this study is to experimentally and computationally investigate the aerodynamic characteristics of three tires 185/65 R14 with different patterns under loaded. A wind tunnel test model was first established using three-dimensional (3D) printing with a ratio of 1:1, and the pressure coefficients Cp of the three tires with different patterns are measured. The paper then conducted computational fluid dynamics (CFD) simulations for analyzing the pressure and flow characteristics. The accuracy of CFD simulation is verified by comparing the simulation results with the test results of pressure coefficients Cp, and they are of good consistency. While, the general analysis of pressure coefficients Cp results of the three tires indicates high-pressure area on the windward surface, and occurrence of low-pressure area on the leeward surface, the pressure coefficients Cp of all three tires decreased firstly and then increased along in the air flow direction. The authors finally analyzed the effect of tread patterns on the flow field around the tire and revealed the differences between flow characteristics and aerodynamic drag. The results show that, angle of tire lateral groove has great effect on the flow field characteristics such that; the more the angle of lateral groove agrees with the air flow direction, the less the flow separation and flow vortices, and a minimum observable aerodynamic drag. The research provides a guidance for the design of low aerodynamic drag tires, and helps to illustrate the impact of tire aerodynamics on the car body in the future.

Genetic algorithm based cooling energy optimization of data centers

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jayati Athavale ◽  
Minami Yoda ◽  
Yogendra Joshi
Keyword(s):  
Genetic Algorithm ◽  
Energy Consumption ◽  
Power Consumption ◽  
Data Center ◽  
Load Distribution ◽  
Data Centers ◽  
Cooling Power ◽  
Temperature Prediction ◽  
Content Type ◽  
Optimization Framework

Purpose This study aims to present development of genetic algorithm (GA)-based framework aimed at minimizing data center cooling energy consumption by optimizing the cooling set-points while ensuring that thermal management criteria are satisfied. Design/methodology/approach Three key components of the developed framework include an artificial neural network-based model for rapid temperature prediction (Athavale et al., 2018a, 2019), a thermodynamic model for cooling energy estimation and GA-based optimization process. The static optimization framework informs the IT load distribution and cooling set-points in the data center room to simultaneously minimize cooling power consumption while maximizing IT load. The dynamic framework aims to minimize cooling power consumption in the data center during operation by determining most energy-efficient set-points for the cooling infrastructure while preventing temperature overshoots. Findings Results from static optimization framework indicate that among the three levels (room, rack and row) of IT load distribution granularity, Rack-level distribution consumes the least cooling power. A test case of 7.5 h implementing dynamic optimization demonstrated a reduction in cooling energy consumption between 21%–50% depending on current operation of data center. Research limitations/implications The temperature prediction model used being data-driven, is specific to the lab configuration considered in this study and cannot be directly applied to other scenarios. However, the overall framework can be generalized. Practical implications The developed framework can be implemented in data centers to optimize operation of cooling infrastructure and reduce energy consumption. Originality/value This paper presents a holistic framework for improving energy efficiency of data centers which is of critical value given the high (and increasing) energy consumption by these facilities.

Employing Thermal Zones for Energy Optimization in Data Centers

2011 ◽  
Author(s):  
Srinivas Yarlanki ◽  
Rajarshi Das ◽  
Hendrik Hamann ◽  
Vanessa Lopez ◽  
Andrew Stepanchuk
Keyword(s):  
Energy Consumption ◽  
Data Centers ◽  
Heat Dissipation ◽  
Energy Savings ◽  
Local Level ◽  
Supply And Demand ◽  
Critical Issue ◽  
Cooling Power ◽  
Joint Management

Energy consumption has become a critical issue for data centers, triggered by the rise in energy costs, volatility in the supply and demand of energy and the wide spread proliferation of power-hungry information technology (IT) equipment. Since nearly half the energy consumed in a data center (DC) goes towards cooling, much of the efforts in minimizing energy consumption in DCs have focused on improving the efficiency of cooling strategies by optimally provisioning the cooling power to match the heat dissipation in the entire DC. However, at a more granular level within the DC, the large range of heat densities of today’s IT equipment makes this task of provisioning cooling power at the level of individual computer room air conditioning (CRAC) units much more challenging. In this work, we employ utility functions to present a principled and flexible method for determining the optimal settings of CRACs for joint management of power and temperature objectives at a more granular level within a DC. Such provisioning of cooling power to match the heat generated at a local level requires the knowledge of thermal zones — the region of DC space cooled by a specific CRAC. We show how thermal zones can be constructed for arbitrary settings of CRACs using the potential flow theory. As a case study, we apply our methodology in a 10,000 sq. ft commercial DC using actual measured conditions and evaluate the usefulness of the method by quantifying possible energy savings in this DC.

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