Experimental study of subcooled flow boiling heat transfer on micro-pin-finned surfaces in short-term microgravity

Liu, Bin; Zhao, Jun; Deng, Yueping; Wei, Jinjia

doi:10.1016/j.expthermflusci.2018.05.003

Cited by 27 publications

(4 citation statements)

References 59 publications

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“…Part of hydrogen bonds is restructuring in the vicinity of the spherical part of the drop surface and as a result one obtains the dependence between the surface tension δ and the hydrogen bond energy (23)(24)(25):…”

Section: Luck Views the Water Like Consisting Of O-h•••o Groupsmentioning

confidence: 99%

Application of infrared spectral analyses for medicinal plants containing calcium (Ca2+)

Ignatov¹,

Balabanski²,

Angelcheva³

2022

Plant Sci. Today

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A study was performed with the methods of Non-equilibrium energy spectrum (NES), Differential non-equilibrium energy spectrum (DNES), mathematical models and water cluster analysis on the changes of hydrogen bonds energy distribution in aqueous solutions due to calcium ions (Ca2+) from the medicinal plants: Origanum vulgare L., Thymus vulgaris L., Mentha longifolia L., Petroselinum crispum Mill., Sideritis scardica Griseb., Salvia officinalis L. All of them are known to contain more than 1000 mg/100 g of calcium ions. The local maximum at (E = -0.1112 eV) (? = 11.15 ?m) (? = 897 cm-1) in all investigated solutions was associated with the presence of calcium ions by Student’s t-test at P<0,05. In the proposed practical approach, the solutions had similar clustering patterns at E = -0.1387 eV, corresponding to water clusters of 16-20 water molecules. These findings from different plant species further expand the evidence about the specific influence of calcium ions on the -0.1112 eV hydrogen bonds energy level in aqueous solutions.

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Section: Luck Views the Water Like Consisting Of O-h•••o Groupsmentioning

confidence: 99%

Application of infrared spectral analyses for medicinal plants containing calcium (Ca2+)

Ignatov¹,

Balabanski²,

Angelcheva³

2022

Plant Sci. Today

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“…It was observed that fin configuration and pitch have significant impacts on CHF and the boiling heat transfer coefficient. In another experiment they 24,25 used the drop tower facility to analyze nucleate boiling heat transfer experimentally and noticed that the radius of bubble detachment increases with the increase of heat flux. A new model of micro‐pin‐fin structure was established to anticipate the radius of bubble departure on microfin surface under microgravity.…”

Section: Experimental Studiesmentioning

confidence: 99%

Improvement of heat transfer through fins: A brief review of recent developments

Maji¹,

Choubey

2020

Heat Trans

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Fins or extended surfaces are generally used in heat exchangers to enhance heat transfer between the main surface and ambient fluid. Various types of simple-shaped fins, namely, rectangular, square, annular, cylindrical, and tapered, have been used with different geometrical combinations. To satisfy industrial demand, different trials have also been carried out for designing optimized fins. The optimization of fins can be performed either by enhancing heat dissipation at an exact fin weight or by diminishing the weight of the fin by precise heat dissipation. Recently a notable amount of work on some typical fins, like, porous fins and perforated fins, has also been carried out. This paper presents a brief review on heat transfer enhancement using fins of different types considering variable thermophysical and geometric parameters, which will also be useful for future use of geometrical modifications of extended surfaces, based on the cost and availability of space.analytical approach, computational approach, experimental approach, perforated fin, porous fin | INTRODUCTIONAdvanced technologies need high-performance heat transfer equipment. Techniques for enhancing the heat transfer rate are classified into two categories: active and passive methods. In the design point of view, active methods are complex as they require some extraneous power input for necessary flow adjustments and to improve the heat transfer rate and thus applications are limited. On the other hand, passive methods require geometrical or surface adjustments to the flow passage by incorporating additional devices. Additionally, by interrupting or varying the existing flow behavior (except for extended surfaces); higher heat transfer coefficients are promoted through this method, which is also followed by an increase in the corresponding pressure drop. The amount of conduction, convection, and radiation of an object shows the amount of heat it transfers. The heat transfer rate is enhanced by increasing the temperature difference between the object and the environment or by enhancing the coefficient of convective heat transfer or by maximizing the surface area of the body. In some cases, it is not appropriate or cost effective to alter the first two options. Introducing a fin to a body, however, expands the surface area and sometimes this is a cost-effective solution for heat transfer problems. Extended surfaces or fins are illustrations of passive methods that are generally used in different industrial applications for the enhancement of heat transfer between the primary surface (heat sink) and the surrounding fluid. Currently reducing the cost and size of fins is the key target of the fin industry. This demand is generally met by the high-thermal-conductivity and costly metals used to fabricate finned surfaces. Many efforts have been made to construct optimized fins. (a) By changing the size and shape of the solid fin: Instead of a longitudinal rectangular solid fin, if the geometry of fin design is changed, the performance parameters and heat tr...

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“…7219 veri noktası kullanarak geliştirdikleri model, tüm veri tabanı üzerinden %23.4 ortalama mutlak hata ile verilerin %72'sini tahmin edebilmiştir. [9] çalışmasında FC-72'nin mikro pim tipi kanatçıklı bir ısı alıcıdaki aşırı soğuk kaynamalı akış incelenmiştir. Düşük ve orta düzeyli ısı akısı değerlerinde yer çekiminin kaynamalı akışta ısı transferi üzerinde kabarcıkların yüzeyden ayrılması açısından bir etkisinin olmadığını, yüksek ısı akılı bölgede ısıl performansın düştüğünü ve kanal içindeki kabarcık birikiminin kritik ısı akısına yol açtığını ifade etmişlerdir.…”

Section: Gi̇ri̇ş (Introduction)unclassified

Mi̇kro Pi̇m Ti̇pi̇ Kanatçikli Ve Mi̇kro Oyuklu Isi Alicida Doymuş Kaynamali Akişin Deneysel İncelenmesi̇

Markal

Kul

2023

Konya Journal of Engineering Sciences

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Mikrokanallarda kaynamalı akış, hava araçlarındaki yüksek kapasiteli elektronik sistemler, bilgisayar işlemcileri ve elektrikli araç bataryaları gibi yüksek yoğunluklu atık ısının açığa çıktığı sistemlerde, sürdürülebilirlik ve güvenli çalışma koşulları için gerekli olan soğutma çözümlerini sunma potansiyeline sahip popüler bir ısıl kontrol tekniğidir. Bu makalede, farklı kütle (136 ve 250 kg m-2 s-1) ve ısı akısı (132 – 272 kW m-2) değerlerinde deiyonize suyun kademeli olarak genişleyen akış kesitine ve yapay kabarcıklaşma oyuklarına sahip mikro pim tipi kanatçıklı ısı alıcıda (modifiye edilmiş ısı alıcı, MIA) doymuş kaynamalı akışı deneysel olarak incelenmiştir. Sonuçlar düz duvarlı paralel mikro kanallı ısı alıcı (konvansiyonel ısı alıcı, KIA) üzerinden karşılaştırmalı olarak sunulmuştur. İş akışkanının giriş sıcaklığı yaklaşık 75ºC’da sabit tutulmuştur. Yüksek hızlı kamera ile akış görüntüleri alınmış (1000 fps) ve fiziksel mekanizma görüntülerle desteklenerek irdelenmiştir. MIA’da, KIA’ya kıyasla, iki fazlı ısı transfer katsayısında %827.2’ye kadar artış sağlanmış ve kaynama kararsızlıkları etkin bir şekilde bastırılabilmiştir. Isı transferindeki iyileşmeye karşı, basınç düşümünde %50.5’e kadar artış olmuştur. Genel karakter olarak, her iki ısı alıcısında da kütle akısının basınç düşümü üzerindeki etkisi görece ihmal edilebilir düzeyde olup, artan kütle akısı ile ısı transfer katsayıları azalmaktadır. MIA’ya ait sonuçlar, KIA’ya kıyasla, kütle akısındaki değişimden görece daha çok etkilenmektedir.

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Experimental study of subcooled flow boiling heat transfer on micro-pin-finned surfaces in short-term microgravity

Cited by 27 publications

References 59 publications

Application of infrared spectral analyses for medicinal plants containing calcium (Ca2+)

Application of infrared spectral analyses for medicinal plants containing calcium (Ca2+)

Improvement of heat transfer through fins: A brief review of recent developments

Mi̇kro Pi̇m Ti̇pi̇ Kanatçikli Ve Mi̇kro Oyuklu Isi Alicida Doymuş Kaynamali Akişin Deneysel İncelenmesi̇

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