دانلود فایل بیوگرافی بلازیوس شاگرد پرانتل
در این مقاله دربارۀ بیوگرافی بلازیوس شاگرد پرانتل و کارهای تحقیقاتی وی به اختصار صحبت شده است.
دانلود مقاله بررسی کارایی پدهای سلولزی کولرهای تبخیری Investigating the performance of cellulosic evaporative cooling pads
در این مقاله عملکرد سه نوع پد سلولزی موجود در بازار و مورد استفاده در کولرهای تبخیری در یک تونل باد بصورت تجربی بررسی و با یکدیگر مقایسه شده است.
دانلود مقاله مصرف آب کولرهای تبخیری Evaporative cooler water use
در این مقاله انواع کولرهای تبخیری تشریح و میزان مصرف آب آنها بررسی و مقایسه شده است.
دانلود مقاله توسعه یک دستگاه جدید برای آزمایش خستگی خمشی Development of a New Device for Bending Fatigue Testing
در این مقاله 18 صفحه ای جزئیات مربوط به طراحی و ساخت و تست دستگاه تست خستگی خمشی مواد کامپوزیت و قابلیتهای این دستگاه به اختصار تشریح شده است.
دانلود مقاله دستگاه آزمایشگاهی برای اندازه گیری ضریب هدایت حرارتی مایعاتExperimental Set-Up for The Measurement of The Thermal Conductivity of Liquids
The paper describes an in house made experimental set-up that
measures the thermal conductivity of liquids. The measurement principle is
based on the Transient Hot Wire Method. The theoretical bases of the mea-
surement method are ¯rstly presented, and then our original experimental im-
plementation is described. The hardware as well as the software design reveals
the simple con¯guration of the measurement set-up that contains high perfor-
mance inexpensive components. It is also simple to use and well suited for
research laboratories, data being stored either in text, or in graphical ¯les. Fi-
nally, based on experimental results, the measurement accuracy and sensibility
performances are discussed and compared with other instruments in literature.
دانلود مقاله جریان پتانسیل سیالات لزج: نوشته های تاریخی Potential flow of viscous fluids: Historical notes
In this essay I will attempt to identify the main events in the history of thought about irrotational flow of viscous fluids.
I am of the opinion that when considering irrotational solutions of the Navier–Stokes equations it is never necessary and
typically not useful to put the viscosity to zero. This observation runs counter to the idea frequently expressed that potential
flow is a topic which is useful only for inviscid fluids; many people think that the notion of a viscous potential flow is an
oxymoron. Incorrect statements like ‘‘. . . irrotational flow implies inviscid flow but not the other way around’’ can be
found in popular textbooks.
Though convenient, phrases like ‘‘inviscid potential flow’’ or ‘‘viscous potential flow’’ confuse properties of the flow
(potential or irrotational) with properties of the material (inviscid or viscous); it is better and more accurate to speak
of the irrotational flow of an inviscid or viscous fluid.
Every theorem about potential flow of perfect fluids with conservative body forces applies equally to viscous fluids in
regions of irrotational flow.
دانلود مقاله لایه مرزی لودویگ پرانتل Ludwig Prandtl’s Boundary Layer
این مقاله خلاصه ای دربارۀ اهمیت دستاورد بزرگ قرن یعنی ئظریۀ لایه مرزی پروفسور لودویگ پرانتل و دانشجویانش از زبان دانشمند بزرگ ایرودینامیک پروفسور اندرسون می باشد. اندرسون معتقد است پرانتل می بایست برای این نظریۀ خود در علم فیزیک، جایزۀ نوبل دریافت می نمود.
دانلود مقاله فناوریهای مبدلهای حرارتی فشرده برای کاربردهای کوره های بازیاب گرما (رکوپراتورها )COMPACT HEAT EXCHANGER TECHNOLOGIES FOR THE HTRs RECUPERATOR APPLICATION
Modern HTR nuclear power plants which are now under development (projects GT-MHR, PBMR)
are based on the direct cycle concept. This concept leads to a more important efficiency compared to
the steam cycle but requires the use of high performance components such as an helium/helium heat
exchanger called recuperator to guarantee the cycle efficiency. Using this concept, a net plant
efficiency of around 50% can be achieved in the case of an electricity generating plant. As geometric
constraints are particularly important for such a gas reactor to limit the size of the primary vessels,
compact heat exchangers operating at high pressure and high temperature are attractive potential
solutions for the recuperator application. In this frame, Framatome and CEA have reviewed the
various technologies of compact heat exchangers used in industry. The first part of the paper will give
a short description of the heat exchangers technologies and their rcinges of application. In a second
part, a selection of potential compact heat exchangers technologies are proposed for the recuperator
application. This selection will be based upon their capabilities to cope with the operating conditions
parameters (pressure, temperature, flow rate) and with other parameters such as fouling, corrosion,
compactness, weight, maintenance and reliability.
دانلود مقاله مروری بر فناوریهای پایدار فعلی و آینده توربینهای گازی An overview of current and future sustainable gas turbine technologies
در این مقاله 36 صفحه ای، مروری بر فناوریهای وربینهای گازی در شرایط فعلی و در آینده ارائه شده است. انواع سیکلهای توربینهای گازی و مزایای هریک نیز بیان شده است.
دانلود مقاله مروری بر لوله های گرمایی حلقوی A Review of Concentric Annular Heat Pipes
در این مقاله مروری بر تحقیقات قبلی دربارۀ لوله های گرمایی معمولی و حلقوی وجود دارد. مطالعۀ آن برای دانشجویان علاقمند به فناوری Heat Pipe اکیداً توصیه می شود.
A detailed description of a concentric annular heat pipe (CAHP) operation is presented in low to moderate temperature
ranges (50–200◦C). The steady-state response of a CAHP to various heat fluxes in the evaporator and condenser sections
are discussed. Two-dimensional mathematical modeling of the fluid flow and heat transfer in the annular vapor space and
the wicks are described. The fundamental aspects and limitations of the operation of a CAHP are also discussed. Previously
used numerical and experimental approaches for the analysis of the CAHPs and some related concepts are reviewed. The
Navier-Stokes and similar equations are recommended for the simulation of fluid flow and heat transfer in the annular vapor
space and the wicks. A number of important concepts, such as two-phase flow, heat transfer in the heat pipe wicks, the
vapor–liquid interface conditions, design considerations, testing, and manufacture of a CAHP, are also briefly discussed.
The results of this research have shown that the available numerical and experimental data in the literature are sufficiently
accurate in many applications. However, new mathematical models and experimental works are needed for the better design
and manufacture of various types of CAHPs.