Sharif Digital Repository

Size and number of high-performance data centers are fast growing all over the world in recent years. The growth in the leakage power consumption of servers along with its exponential dependency on the ever increasing process variation in nanometer technologies have made it inevitable to move toward variation-aware power reduction strategies. In this thesis, we simultaneously apply thermal- and variation-aware server placement and chassis consolidation methods to reduce total power consumption of data centers. We introduce two server placement heuristics as well as an Integer Linear Programming (ILP)-based server placement method based on power consumption of each server and the data center... 

This thesis tries to suggest a simple solution to reduce the amplitude of occurred fluctuations in mixing tees. Temperature fluctuations can induce cyclical thermal stress and thermal fatigue. In order to estimate the lifetime of pipeline material and reduce the frequency and amplitude of these fluctuations, an accurate diagnosis of these fluctuations must be conducted. For this aim, a comparison between Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) models was carried out to show the ability of LES model in prediction of temperature fluctuations. The effect of Peclet number on the amplitude was discussed. The effect of placing simple pipe segments and orifices to... 

Gas turbine discs must be tested before they are installed in an engine for their mechanical properties and resistance to crack growth. Such test is usually done in a device called Spin Tester in which high rotational speed and temperature fluctuations can be applied to a disc. In this project a plug-in software is developed by which life of gas turbine discs under sever fluctuations of rotating speed and temperature can be assessed. The tests performed in the software are; stress analysis, fatigue analysis, crack initiation point, and finally 3-D fatigue crack growth path. The software is written using Python programming in ABAQUS. The software adds a sub-menu in ABAQUS Plugins as "Engine... 

Integrated silicon photonic networks have attracted a lot of attention in the recent decade due to their potential for low-power and high-bandwidth communications. However, despite high bandwidth and low-loss data communication capability, optical NoCs are susceptible to on-chip temperature variations. In these promising networks, packets’ erroneous routing due to thermally-induced resonant wavelength shift of microring resonators are common temporary faults unless heat control mechanism is adopted. In other words, thermal drifts may paralyze wavelength-based operation of these networks. On the other hand, employing a heat control mechanism in an ONoC necessitates developing thermal fault...