پایان نامه های دکترا
mohammad layeghi
دانلود پایان نامه انگلیسی تولید قطره در مقیاس نانولیتر تا فمتولیتر Droplet Generation From the Nanoliter to the Femtoliter Range

This thesis provides a general description of micro droplet generation at low and
medium Weber numbers using analytical, numerical and experimental methods in an
engineering manner of contemplation. Based on the presented results guidelines are
deduced to support the designing and operating any type of micro droplet generator.

mohammad layeghi
دانلود پایان نامه انگلیسی دربارۀ ایرودینامیک توربین بادی

This thesis hence aims to improve our understanding of rotor aerodynamics
in yaw using wind tunnel experiments. Its concrete objectives are:
quantify the effects of experimentally observed yaw misalignment on
rotor inflow and blade loads
• identify the aerodynamic mechanisms governing the effects of yaw misalignment
on rotor inflow and blade loads
• assess the validity of semi-empirical submodels, used to patch BEMtheory;
the Glauert momentum equation for yaw, induction non-uniformity
corrections in yaw, airfoil dynamic stall models.

دانلود پایان نامه انگلیسی میدان جریان و انتقال حرارت در دسته میله ها Rod Bundles

Prcsentcd in this study is an investigation of nirbulcnt flow and heat transfcr near
narrow gaps of rod bundlcs. At first. practical crnpirical corrclations for the subchanncl
avcragc and thc gay, local hcat transfer coeficicnts wcrc fincd to cxperimcntal I-csults
availablc in the literaturc. Then. thc thcsis prcsents a new technique. using a pcndulum. for
thc calibration of hot-wirc ancmomctcrs ovcr low vclocity ranges. a signal analysis
procedurc for thrce-sensor hot-wirc probes. and a mcthod for thc cnhancemcnt of the rcsults
of the Variable Interval Timc Average (VITA) conditional sampling technique. al1 used in
the main cxperimcntal snidy.

دانلود پایان نامه انگلیسی آنالیز، تولید و تست یک سیستم میکروپیشرانش بر پایه میکروالکترومکانیکال سیستم ها

Various trends in the spacecraft industry are driving the development of low-thrust propulsion systems.
These may be needed for fine attitude control, or to reduce the mass of the propulsion system through the
use of small lightweight components. The nozzle converts the stored energy in a pressurized gas into kinetic
energy through an expansion. The nozzle efficiency is characterized by the amount of kinetic energy leaving
the nozzle, and is governed by the exit velocity. Because of the increase in viscous losses as scale is reduced,
it was feared that high Mach number supersonic flows could not be generated in microdevices. However, a
scaling analysis indicates that the reduction in throat area can be offset by an increase in operating pressure
to maintain a constant Reynolds number. Therefore, thrust can be decreased by reducing the nozzle scale,
and viscous losses mitigated by running at higher chamber pressures.