CFD Modeling of the Distribution of Airborne Particulate Contaminants Inside Data Center Hardware

2020 ◽  
Author(s):  
Satyam Saini ◽  
Kaustubh K. Adsul ◽  
Pardeep Shahi ◽  
Amirreza Niazmand ◽  
Pratik Bansode ◽  
...  
Keyword(s):  
Data Center ◽  
High Performance ◽  
Phase Particle ◽  
Cfd Modeling ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Particle Modeling ◽  
Free Air ◽  
Discrete Phase ◽  
Particulate Contaminants

Abstract Modern-day data center administrators are finding it increasingly difficult to lower the costs incurred in mechanical cooling of their IT equipment. This is especially true for high-performance computing facilities like Artificial Intelligence, Bitcoin Mining, and Deep Learning, etc. Airside Economization or free air cooling has been out there as a technology for a long time now to reduce the mechanical cooling costs. In free air cooling, under favorable ambient conditions of temperature and humidity, outside air can be used for cooling the IT equipment. In doing so, the IT equipment is exposed to sub-micron particulate/gaseous contaminants that might enter the data center facility with the cooling airflow. The present investigation uses a computational approach to model the airflow paths of particulate contaminants entering inside the IT equipment using a commercially available CFD code. A Discrete Phase Particle modeling approach is chosen to calculate trajectories of the dispersed contaminants. Standard RANS approach is used to model the airflow in the airflow and the particles are superimposed on the flow field by the CFD solver using Lagrangian particle tracking. The server geometry was modeled in 2-D with a combination of rectangular and cylindrical obstructions. This was done to comprehend the effect of change in the obstruction type and aspect ratio on particle distribution. Identifying such discrete areas of contaminant proliferation based on concentration fields due to changing geometries will help with the mitigation of particulate contamination related failures in data centers.

Air Flow Pattern and Path Flow Simulation of Airborne Particulate Contaminants in a High-Density Data Center Utilizing Airside Economization

2018 ◽  
Author(s):  
Gautham Thirunavakkarasu ◽  
Satyam Saini ◽  
Jimil Shah ◽  
Dereje Agonafer
Keyword(s):  
Data Center ◽  
Carbon Particle ◽  
High Density ◽  
Submicron Particles ◽  
Air Cooling ◽  
Density Data ◽  
Particulate Contamination ◽  
Free Air ◽  
First Choice ◽  
Particulate Contaminants

The percentage of the energy used by data centers for cooling their equipment has been on the rise. With that, there has been a necessity for exploring new and more efficient methods like airside economization, both from an engineering as well as business point of view, to contain this energy demand. Air cooling especially, free air cooling has always been the first choice for IT companies to cool their equipment. But, it has its downside as well. As per ASHRAE standard (2009b), the air which is entering the data center should be continuously filtered with MERV 11 or preferably MERV 13 filters and the air which is inside the data center should be clean as per ISO class 8. The objective of this study is to design a model data center and simulate the flow path with the help of 6sigma room analysis software. A high-density data center was modelled for both hot aisle and cold aisle containment configurations. The particles taken into consideration for modelling were spherical in shape and of diameters 0.05, 0.1 and 1 micron. The physical properties of the submicron particles have been assumed to be same as that of air. For heavier particles of 1 micron in size, the properties of dense carbon particle are chosen for simulating particulate contamination in a data center. The Computer Room Air Conditioning unit is modelled as the source for the particulate contaminants which represents contaminants entering along with free air through an air-side economizer. The data obtained from this analysis can be helpful in predicting which type of particles will be deposited at what location based on its distance from the source and weight of the particles. This can further help in reinforcing the regions with a potential to fail under particulate contamination.

Simplified and Detailed Analysis of Data Center Particulate Contamination At Server and Room Level Using CFD

2021 ◽  
Author(s):  
Satyam Saini ◽  
Pardeep Shahi ◽  
Pratik V Bansode ◽  
Jimil M. Shah ◽  
Dereje Agonafer
Keyword(s):  
Detailed Analysis ◽  
Data Center ◽  
Particle Concentration ◽  
Heat Sinks ◽  
Cooling Power ◽  
Air Cooling ◽  
Component Reliability ◽  
Particulate Contamination ◽  
Free Air ◽  
Particulate Contaminants

Abstract Continuous rise in cloud computing and other web-based services propelled the data center proliferation seen over the past decade. Traditional data centers use vapor-compression-based cooling units that not only reduce energy efficiency but also increase operational and initial investment costs due to involved redundancies. Free air cooling and airside economization can substantially reduce the IT Equipment (ITE) cooling power consumption, which accounts for approximately 40% of energy consumption for a typical air-cooled data center. However, this cooling approach entails an inherent risk of exposing the IT equipment to harmful ultrafine particulate contaminants, thus, potentially reducing the equipment and component reliability. The present investigation attempts to quantify the effects of particulate contamination inside the data center equipment and ITE room using CFD. An analysis of the boundary conditions to be used was done by detailed modeling of IT equipment and the data center white space. Both 2-D and 3-D simulations were done for detailed analysis of particle transport within the server enclosure. An analysis of the effect of the primary pressure loss obstructions like heat sinks and DIMMs inside the server was done to visualize the localized particle concentrations within the server. A room-level simulation was then conducted to identify the most vulnerable locations of particle concentration within the data center space. The results show that parameters such as higher velocities, heat sink cutouts, and higher aspect ratio features within the server tend to increase the particle concentration inside the servers.

Experimental Description of Information Technology Equipment Reliability Exposed to a Data Center Using Airside Economizer Operating in Recommended and Allowable ASHRAE Envelopes in an ANSI/ISA Classified G2 Environment

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Oluwaseun Awe ◽  
Jimil M. Shah ◽  
Dereje Agonafer ◽  
Prabjit Singh ◽  
Naveen Kannan ◽  
...  
Keyword(s):  
Information Technology ◽  
Data Center ◽  
Data Centers ◽  
Operating Cost ◽  
Weather Data ◽  
Air Cooling ◽  
Single Server ◽  
Severity Level ◽  
Equipment Reliability ◽  
Free Air

Abstract Airside economizers lower the operating cost of data centers by reducing or eliminating mechanical cooling. It, however, increases the risk of reliability degradation of information technology (IT) equipment due to contaminants. IT Equipment manufacturers have tested equipment performance and guarantee the reliability of their equipment in environments within ISA 71.04-2013 severity level G1 and the ASHRAE recommended temperature-relative humidity (RH) envelope. IT Equipment manufacturers require data center operators to meet all the specified conditions consistently before fulfilling warranty on equipment failure. To determine the reliability of electronic hardware in higher severity conditions, field data obtained from real data centers are required. In this study, a corrosion classification coupon experiment as per ISA 71.04-2013 was performed to determine the severity level of a research data center (RDC) located in an industrial area of hot and humid Dallas. The temperature-RH excursions were analyzed based on time series and weather data bin analysis using trend data for the duration of operation. After some period, a failure was recorded on two power distribution units (PDUs) located in the hot aisle. The damaged hardware and other hardware were evaluated, and cumulative corrosion damage study was carried out. The hypothetical estimation of the end of life of components is provided to determine free air-cooling hours for the site. There was no failure of even a single server operated with fresh air-cooling shows that using evaporative/free air cooling is not detrimental to IT equipment reliability. This study, however, must be repeated in other geographical locations to determine if the contamination effect is location dependent.

Cfd Modeling of the Distribution of Airborne Particulate Contaminants Inside Data Center Hardware

2021 ◽  
Author(s):  
Kaustubh Adsul ◽  
Satyam Saini ◽  
Pardeep Shahi ◽  
Amirreza Niazmand ◽  
Pratik Bansode ◽  
...  
Keyword(s):  
Data Center ◽  
Cfd Modeling ◽  
Airborne Particulate ◽  
Particulate Contaminants

Energy-Efficient Air Cooling of Data Centers at 2000 W/ft2

2009 ◽  
Author(s):  
Magnus K. Herrlin ◽  
Michael K. Patterson
Keyword(s):  
Energy Efficiency ◽  
Data Center ◽  
Energy Efficient ◽  
Data Centers ◽  
High Heat ◽  
High Density ◽  
Cfd Modeling ◽  
Air Cooling ◽  
Capital Costs ◽  
Design Considerations

Increased Information and Communications Technology (ICT) capability and improved energy-efficiency of today’s server platforms have created opportunities for the data center operator. However, these platforms also test the ability of many data center cooling systems. New design considerations are necessary to effectively cool high-density data centers. Challenges exist in both capital costs and operational costs in the thermal management of ICT equipment. This paper details how air cooling can be used to address both challenges to provide a low Total Cost of Ownership (TCO) and a highly energy-efficient design at high heat densities. We consider trends in heat generation from servers and how the resulting densities can be effectively cooled. A number of key factors are reviewed and appropriate design considerations developed to air cool 2000 W/ft2 (21,500 W/m2). Although there are requirements for greater engineering, such data centers can be built with current technology, hardware, and best practices. The density limitations are shown primarily from an airflow management and cooling system controls perspective. Computational Fluid Dynamics (CFD) modeling is discussed as a key part of the analysis allowing high-density designs to be successfully implemented. Well-engineered airflow management systems and control systems designed to minimize airflow by preventing mixing of cold and hot airflows allow high heat densities. Energy efficiency is gained by treating the whole equipment room as part of the airflow management strategy, making use of the extended environmental ranges now recommended and implementing air-side air economizers.

Energy Efficiency and Air Quality Considerations in Airside Economized Data Centers

2015 ◽  
Author(s):  
Levente J. Klein ◽  
Sergio A. Bermudez ◽  
Fernando J. Marianno ◽  
Hendrik F. Hamann ◽  
Prabjit Singh
Keyword(s):  
Energy Efficiency ◽  
Air Quality ◽  
Data Center ◽  
Data Centers ◽  
High Sensitivity ◽  
Air Cooling ◽  
Improve Energy Efficiency ◽  
Free Air ◽  
Recent Developments ◽  
Contamination Event

Many data center operators are considering the option to convert from mechanical to free air cooling to improve energy efficiency. The main advantage of free air cooling is the elimination of chiller and Air Conditioning Unit operation when outdoor temperature falls below the data center temperature setpoint. Accidental introduction of gaseous pollutants in the data center along the fresh air and potential latency in response of control infrastructure to extreme events are some of the main concerns for adopting outside air cooling in data centers. Recent developments of ultra-high sensitivity corrosion sensors enable the real time monitoring of air quality and thus allow a better understanding of how airflow, relative humidity, and temperature fluctuations affect corrosion rates. Both the sensitivity of sensors and wireless networks ability to detect and react rapidly to any contamination event make them reliable tools to prevent corrosion related failures. A feasibility study is presented for eight legacy data centers that are evaluated to implement free air cooling.

Data Center Housing High Performance Supercomputer Cluster: Above Floor Thermal Measurements Compared To CFD Analysis

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Roger Schmidt ◽  
Madhusudan Iyengar ◽  
Joe Caricari
Keyword(s):  
New York ◽  
Data Center ◽  
High Performance ◽  
Data Centers ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Heat Fluxes ◽  
Cfd Modeling ◽  
Peak Performance ◽  
Cfd Analysis

With the ever increasing heat dissipated by information technology (IT) equipment housed in data centers, it is becoming more important to project the changes that can occur in the data center as the newer higher powered hardware is installed. The computational fluid dynamics (CFD) software that is available has improved over the years. CFD software specific to data center thermal analysis has also been developed. This has improved the time lines of providing some quick analysis of the effects of new hardware into the data center. But it is critically important that this software provide a good report to the user of the effects of adding this new hardware. It is the purpose of this paper to examine a large cluster installation and compare the CFD analysis with environmental measurements obtained from the same site. This paper shows measurements and CFD data for high powered racks as high as 27 kW clustered such that heat fluxes in some regions of the data center exceeded 700 W per square foot. This paper describes the thermal profile of a high performance computing cluster located in an data center and a comparison of that cluster modeled via CFD. The high performance advanced simulation and computing (ASC) cluster had a peak performance of 77.8 TFlop/s, and employed more than 12,000 processors, 50 Tbytes of memory, and 2 Pbytes of globally accessible disk space. The cluster was first tested in the manufacturer’s development laboratory in Poughkeepsie, New York, and then shipped to Lawrence Livermore National Laboratory in Livermore, California, where it was installed to support the national security mission of the U.S. Detailed measurements were taken in both data centers and were previously reported. The Poughkeepsie results will be reported here along with a comparison to CFD modeling results. In some areas of the Poughkeepsie data center, there were regions that did exceed the equipment inlet air temperature specifications by a significant amount. These areas will be highlighted and reasons given on why these areas failed to meet the criteria. The modeling results by region showed trends that compared somewhat favorably but some rack thermal profiles deviated quite significantly from measurements.

Improved Cooling of Electromagnetics by Directed Airflow

2013 ◽  
Author(s):  
Scott Downing ◽  
Adam Fain ◽  
Pradip Majumdar
Keyword(s):  
High Performance ◽  
Experimental Testing ◽  
Hot Spot ◽  
Test Methods ◽  
Cfd Modeling ◽  
Air Cooling ◽  
Low Velocity ◽  
Article Surface ◽  
Two Phases ◽  
Geometrical Dimensions

The transformers in aircraft power conversion are often very heavy and represent a significant fuel or range penalty. Being thermally sized, improved cooling methods would allow downsizing and thereby reduced weight. Since the conductive paths in these metal “dense” devices are good, the controlling thermal resistance is typically the convective coefficient. The goal of this study was to optimize the convective air cooling across transformers by parametrically testing candidate shroud geometries to minimize average and hot spot surface temperatures with minimal fan power. Experimental results from a low velocity wind tunnel were well correlated by CFD modeling, providing confidence in continued shroud development with only CFD or experimentally. A simple cubic test block was selected as surrogate to generalize and simplify both test methods and results. A new “goodness” parameter was developed that included both the heat transfer performance and pressure penalty for a comparative index of shroud designs. The work was divided into two phases. Phase-A used numerical modeling to study a variety of different shapes to select the best for experimental testing. Phase-B included the testing and further parametric evaluation with CFD studies. A parameter was developed that quantified the effect of conductive spreading on the test article surface. Presented here are the results of these studies, where several general shroud shapes emerged as high performance in comparative evaluation. Following the down select, specific geometrical dimensions relative to the duct and mock transformer sizes were further optimized.

Data Center Housing the World’s 3rd Fastest Supercomputer: Above Floor Thermal Measurements Compared to CFD Analysis

2007 ◽  
Author(s):  
Roger Schmidt ◽  
Madhusudan Iyengar ◽  
Joe Caricari
Keyword(s):  
Data Center ◽  
High Performance ◽  
Data Centers ◽  
Floor Tile ◽  
Heat Fluxes ◽  
Electronic Equipment ◽  
Cfd Modeling ◽  
Peak Performance ◽  
Cfd Analysis ◽  
Air Temperatures

With the ever increasing heat dissipated by IT equipment housed in data centers it is becoming more important to project the changes that can occur in the data center as the newer higher powered hardware is installed. The computational fluid dynamics (CFD) software that is available has improved over the years and some CFD software specific to data center thermal analysis has been developed. This has improved the timeliness of providing some quick analysis of the effects of new hardware into the data center. But it is critically important that this software provide a good report to the user of the effects of adding this new hardware. And it is the purpose of this paper to examine a large cluster installation and compare the CFD analysis with environmental measurements obtained from the same site. This paper shows measurements and CFD analysis of high powered racks as high as 27 kW clustered such that heat fluxes in some regions of the data center exceeded 700 Watts/ft2 (7535 W/m2). This paper describes the thermal profile of a high performance computing cluster located in an IBM data center and a comparison of that cluster modeled with CFD software. The high performance Advanced Simulation and Computing (ASC) cluster, developed and manufactured by IBM, is code named ASC Purple. It is the World’s 3rd fastest supercomputer [1], operating at a peak performance of 77.8 TFlop/s. ASC Purple, which employs IBM pSeries p575, Model 9118, contains more than 12,000 processors, 50 terabytes of memory, and 2 petabytes of globally accessible disk space. The cluster was first tested in the IBM development lab in Poughkeepsie, NY and then shipped to Lawrence Livermore National Labs in Livermore, California where it was installed to support our national security mission. Detailed measurements were taken in both data centers of electronic equipment power usage, perforated floor tile airflow, cable cutout airflow, computer room air conditioning (CRAC) airflow, and electronic equipment inlet air temperatures and were report in Schmidt [2], but only the IBM Poughkeepsie results will be reported here along with a comparison to CFD modeling results. In some areas of the Poughkeepsie data center there were regions that did exceed the equipment inlet air temperature specifications by a significant amount. These areas will be highlighted and reasons given on why these areas failed to meet the criteria. The modeling results by region showed trends that compared somewhat favorably but some rack thermal profiles deviated quite significantly from measurements.

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