دانلود مقاله مروری بر مطالعه پارامتری انتقال حرارت در جوشش استخری نانوسیالها برای افزایش شار حرارتی بحرانی Parametric study of pool boiling heat transfer with nanofluids for the enhancement of critical heat flux: A review
Over the last decade, numerous investigations have been carried out using engineered colloidal fluids
called nanofluids in pool boiling for the enhancement of critical heat flux (CHF) which is otherwise
limited by the use of base fluids. Though there are contradicting results in CHF enhancement, almost all
the researchers identified that there is an enhancement in CHF by the addition of nanoparticles (1
e100 nm size) with base fluid. The deposition of nanoparticles on the heater surface during boiling of
nanofluids is the major factor for the enhancement of CHF. In fact, the CHF enhancement results are
influenced by the various parameters such as size of nanoparticles, method of preparation of nanofluids,
and its concentration. This article reviews in detail the various factors for the enhancement of CHF and
provides further research direction which helps the readers to understand the pool boiling heat transfer
in a better way. Also, the mechanisms of CHF enhancement by exploring various boiling heat transfer
theories have been addressed.
دانلود مقاله مروری بر افزایش انتقال حرارت جوششی نانوسیالها و پوششهای نانو A review of enhancement of boiling heat transfer through nanofluids and nanoparticle coatings
This review traces the development of nanofluid pool boiling from its beginning (1984) to the
present through a sampling of studies that have interested the authors and which have led to the
latest findings at the University of Texas at Arlington (UTA). The studies of thermophysical
properties of nanofluids are briefly covered. Several works in the last 7 years are highlighted to
illustrate the modes of nanofluid pool boiling testing, the variability of nanofluid boiling heat
transfer (BHT), and the postulations of causes of this behavior. Starting in 2006, the wettability
increase in the nanoparticle coating, generated during the nanofluid pool boiling, is recognized as
the source of critical heat flux (CHF) enhancement through its effect on the dynamics of hot spots
and departing bubbles. The reasons for the observed contradictory BHT behavior are not yet fully
clear, but recently at UTA, nanofluid boiling heat transfer has shown to be transient due to the
dynamic nature of the formation of the nanoparticle coating. Also at UTA, the mechanism of
nanoparticle deposition on the heated surface has been further confirmed. Thus, nanofluid boiling
has led back to heat transfer enhancement through surface modification in nanoscale. These
developments from 2006 are covered in more detail.
دانلود مقاله مروری بر انتقال حرارت جوششی نانو سیال ها A review of flow boiling heat transfer of nanofluids
The flow boiling heat transfer of nanofluids is an important research area which provides many
opportunities to explore new frontiers but also poses great challenges. This paper presents a
comprehensive review on the flow boiling heat transfer of nanofluids, with an emphasis on the heat
transfer coefficient (HTC), critical heat flux (CHF), pressure drop, nanofluid stability, flow and heat
transfer mechanism, and flow pattern and bubble dynamics. Most of the available articles have been
related to the first four topics. Studies related to the last two topics are rare, which are reviewed
because of their importance. The important achievements, inconsistence, and contradictions of the
existing research results are identified, and several topics worthy of attention for future investigations
are identified.