Hamza Salih Erden

Hamza Salih Erden
Istanbul Technical University · Informatics Institute

Ph.D.

About

33
Publications
4,383
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
268
Citations
Citations since 2016
19 Research Items
228 Citations
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050
Introduction
Hamza Salih Erden is a faculty member at Istanbul Technical University, where he leads graduate-level teaching track and research program titled “Thermal Systems in Cloud Infrastructure” at the Informatics Institute. His current research is on the thermodynamic modeling and optimization of data center thermal environment and cooling infrastructure.
Additional affiliations
August 2015 - present
Istanbul Technical University
Position
  • Professor (Assistant)
August 2015 - present
Istanbul Technical University
Position
  • Faculty Member
Description
  • Data Center Infrastructure and Energy Efficiency / Introduction to Thermal Systems Engineering / Cooling and Air Conditioning in Data Centers / Multi-Scale Thermal Modeling of Data Centers / Optimization Methods in Informatics
August 2013 - August 2015
Syracuse University
Position
  • PostDoc Position
Education
May 2009 - August 2013
Syracuse University
Field of study
  • Mechanical and Aerospace Engineering
August 2007 - May 2009
Syracuse University
Field of study
  • Mechanical and Aerospeace Engineering
September 2002 - June 2007
Istanbul Technical University
Field of study
  • Mechanical Engineering

Publications

Publications (33)
Article
Full-text available
High density data centers consume mega watts of electricity for both computing and cooling. Because of the fast paced growth of data center energy demand, effective energy conservation measures must be implemented. The use of on-site combined power generation and cooling systems for data centers that are located on campuses is discussed and compare...
Article
Full-text available
Transient thermal events in air-cooled data centers may lead to undesirable operating conditions such as the formation of hot spots and associated degradation of equipment reliability. These transients may be caused by cooling equipment failures, server load changes, or other time-dependent scenarios in data center operations. This paper introduces...
Article
Computer room air handling (CRAH) bypass (BP) method is an application that reduces the total fan power in air-cooled data centers by lowering CRAH fan speed. BP fans supply the complementary fraction of server airflow from warmer room air through lower-resistance floor openings into the plenum. Hence, chillers need to operate at lower temperatures...
Article
The share of equipment and power use in smaller data centers (DCs) is comparable with that of more massive counterparts. However, they grabbed less attention in the literature despite being less energy-efficient. This study highlights the challenges of setting up a computational fluid dynamics (CFD) model of a 180-m2 small-size high-performance com...
Article
Full-text available
Mechanical cooling is responsible for a significant fraction of the energy consumption of data centers (DCs). Free cooling systems take advantage of ambient conditions to reduce the need for compressor-based cooling. This study utilizes thermodynamic models of major free cooling systems such as the direct air-side economizer (ASE), indirect air-sid...
Article
The computer room air handling (CRAH) bypass (BP) method is a method to reduce the fan energy consumption in data centers. To provide a fraction of the server airflow, CRAH BP fans typically operate across an order of magnitude lower pressure drop across floor tiles compared to that across CRAH units. However, at a higher fraction of BP airflow, CR...
Article
Today, selling electricity to the grid has lost its former profitability with reduced feed-in tariff (FiT) rates. This makes it crucial for prosumers to increase self-consumption and size their photovoltaic (PV) and battery energy storage system (BESS) units accordingly. Self-consumption can be increased through demand-side management (DSM) and an...
Preprint
Full-text available
The recent spike in the demand for high-performance computing (HPC) server systems has created many challenges in data centers (DCs) including thermal management, system reliability sustenance and server failure minimalization. Lately, deep neural networks applied to infrared thermography (IRT) images have been successfully used for fault diagnosis...
Conference Paper
Full-text available
As cloud computing applications have witnessed an exponential growth in recent years, the maintenance of server uptime has never been more important. A fault in a server due to overload, attack, or a misconfiguration of a cooling system can be of imponderable economic and financial loss to the echelons of global institutions. The advent of thermal...
Article
Smart thermostats and home energy management systems (HEMSs) are generally studied separately. However, their joint use can provide a greater benefit. Therefore, this study primarily aims to combine a smart thermostat with a HEMS. The mixed-integer linear programming (MILP)-based HEMS performs day-ahead load scheduling for cost-minimization and pro...
Conference Paper
This study highlights experimental challenges of setting up a computational fluid dynamics (CFD) model of a 180-m2 small-size high-performance computing (HPC) data center (DC) in a university campus and the validation procedure leading to a reasonably accurate CFD model for the investigation of the thermal environment. Experimental results based on...
Article
Aisle containment systems reduce temperature nonuniformities in traditional air-cooled data centers and pave the way for higher cooling air temperature and more efficient operation of the cooling system and wider application of economizers. However, enclosing the aisle does not guarantee the lowest possible cooling infrastructure power. Enclosed ai...
Article
Aisle containment separates hot and cold aisles in air-cooled data centers to prevent hot air recirculation into cold aisle and decrease temperature nonuniformity among the servers. Uniform server inlet temperatures allow the cooling system to operate more efficiently at a higher evaporator temperature. Lower cooling power consumption can be achiev...
Conference Paper
Two time-dependent mathematical and numerical models with different levels of complexity and fidelity were developed to investigate the melting of a phase change material (PCM) configured as a number of aluminum-encased, PCM-filled slabs with embedded micro-channel aluminum tubes, and with parallel air-flow passages interposed between the slabs. Me...
Conference Paper
Aisle containments in data centers help provide uniform server inlet air temperatures. This allows the cooling system to run at a higher evaporator temperature and more efficiently. On the other hand, CRAH units run at higher speeds to ascertain that racks receive sufficient air flow. Since CRAH fan power already constitutes an important component...
Conference Paper
Temperature non-uniformities in traditional data centers can be eliminated or at least reduced by utilizing containment systems. As all servers receive the same inlet air temperature in a contained configuration, the cooling system can be operated more efficiently at a higher temperature, which also increases the potential for free cooling through...
Conference Paper
Lumped capacitance models have been introduced to study transient thermal response of data centers. Chilled water interruption of a Computer Room Air Handling (CRAH) unit is one of several failure scenarios of data center cooling infrastructures. In such a scenario, predicting the transient thermal response of the CRAH unit depends requires the det...
Article
Full-text available
Accurate prediction of data center temperatures and airflow following a transient event, such as the loss of cooling or variation in server load, requires that all sources of thermal mass in the data center be modeled with sufficient accuracy. One of the most important and simultaneously difficult-tomodel types of thermal mass in the data center is...
Conference Paper
The transient behavior of IT equipment can be represented by a lumped thermal capacitance for use in data center level transient thermal simulations. Previous work has proposed a mathematical methodology to extract the necessary lumped capacitance parameters, the server's time constant and heat transfer effectiveness, via air temperature measuremen...
Conference Paper
Current trends in data center cooling infrastructure design drive toward raising the coolant temperature to as high a level as equipment reliability allows in order to reduce the energy consumed by the cooling infrastructure and, consequently, improve (i.e., decrease) the power utilization effectiveness (PUE). However, as currently applied, PUE wou...
Article
Computer servers can be represented by lumped thermal capacitances for the purpose of simulating server and data center transient thermal response to changes in operating conditions or equipment failures. Two parameters are needed to characterize the transient behavior of a lumped-capacitance server: its thermal capacitance and its thermal conducta...
Thesis
Full-text available
This work investigates the transient response of the thermal environment in air cooled data centers through experiments, analytical and computational tools. The key thermal characteristics of the various data center components were extracted from a set of experiments. This includes the development of practical experimental procedures for the therma...
Conference Paper
The Syracuse/IBM Green Data Center utilizes micro turbines in combination with exhaust fired heat exchangers and absorption chillers to produce electrical power, cooling and heating for the data center and surrounding infrastructure. The overall efficiency of cogeneration systems depend greatly on the utilization of turbine exhaust heat. This makes...
Conference Paper
Transient CFD analysis of data centers requires appropriate representations of the transient thermal characteristics of servers. Thermal conductance and thermal capacitance are two determining characteristics for the response of servers under unsteady conditions. Previous studies proposed tests that require detailed temperature and thermal capacita...
Conference Paper
Servers have time constants on the order of several minutes, which is significantly longer than many other time constants observed in data centers. When server thermal masses are not negligible, transient scenarios cannot be modeled appropriately with the steady state boundary conditions. By using the time constant and thermal masses of the servers...
Conference Paper
Conducting experiments on real high-density computer servers can be an expensive and risky task due to the risks associated with unintended inlet temperatures that exceed the server’s red-line temperature limit. Presented herein is the development of the simulated chassis that mimic real computer servers. Briefly, twelve high-power simulated chassi...

Network

Cited By

Projects

Projects (3)
Project
The computer room air handling (CRAH) bypass (BP) method reduces the fan energy consumption in data centers. To provide a fraction of the server airflow, CRAH BP fans typically operate across an order of magnitude lower pressure drop across floor tiles compared to that across CRAH units. However, at a higher fraction of BP airflow, CRAH units are subject to low-temperature operation, which poses an optimization problem. This project contains research findings of multiple relevant projects funded by IBM, Syracuse Center of Excellence, NYSERDA and TÜBİTAK.
Project
The project aims at leveraging the availability of powerful image processing, machine learning and deep learning algorithms to improve the detection and diagnosis accuracy of faults in data centers using thermography.