Parametric optimization of H-type finned tube with longitudinal vortex generators by response surface model and genetic algorithm

Tang, Songzhen; Wang, Feilong; He, Ya‐Ling; Yu, Yang

doi:10.1016/j.apenergy.2019.01.122

Cited by 42 publications

(8 citation statements)

References 28 publications

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“…For the optimization The optimization algorithm used is NSGA-II (Non-dominated Sorting Genetic Algorithm II [34]), which is defined for the present work since can avoid stalling and detect global and multiple local extremes [45]. This algorithm is robust and extensive used for similar researches, which was applied for heat transfer augmentation, pressure drop penalty, and LVG applications [26,31,[46][47][48].…”

Section: Optimization Processmentioning

confidence: 99%

Parametric optimization of a stamped longitudinal vortex generator inside a circular tube of a solar water heater at low Reynolds numbers

et al. 2021

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Solar Water Heater (SWH) has low efficiency and the performance of this type of device needs to be improved to provide useful and ecological sources of energy. The passive techniques of augmentation heat transfer are an effective strategy to increase the convective heat transfer coefficient without external equipment. In this way, recent investigations have been done to study the potential applications of different inserts including wire coils, vortex generators, and twisted tapes for several solar thermal applications. However, few researchers have investigated inserts in SWH which is useful in many sectors where the working fluid operates at moderate temperatures. The longitudinal vortex generators (LVG) have been applied to promote heat transfer enhancement with a low/moderate pressure drop penalty. Therefore, the present work investigated optimal geometric parameters of LVG to enhance the heat transfer for a SWH at low Reynolds number and laminar flow, using a 3D periodical numerical simulation based on the Finite Volume Method coupled to the Genetic Algorithm optimization method (NSGA-II). The LVG was stamped over a flat plate inserted inside a smooth tube operating under a typical residential application corresponding to Reynolds numbers of 300, 600, and 900. The geometric parameters of LGV were submitted to the optimization procedure which can find traditional LVG such as rectangular-winglet and delta-winglet or a mix of them. The results showed that the application of LGVs to enhance heat transfer is an effective passive technique. The different optimal shapes of the LVG for all Reynolds numbers evaluated improved more than 50% of heat transfer. The highest augmentation heat transfer of 62% is found for the Reynolds number 900. However, the best thermo-hydraulic efficiency value is found for the Reynolds number of 600 in which the heat transfer intensification represents 55% of the pressure drop penalty.

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Section: Optimization Processmentioning

confidence: 99%

Parametric optimization of a stamped longitudinal vortex generator inside a circular tube of a solar water heater at low Reynolds numbers

et al. 2021

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“…In addition, the People’s Court Daily , a propaganda mouthpiece of the Supreme People’s Court (hereinafter SPC), often describes female judges who work in criminal divisions as “different” in many ways from their male colleagues. For example, Yu Huafen, a criminal division chief in the Xuanwei district court and a role model for female judges, is said to “perfectly handle her femininity in a masculine court environment” ( Tong & Tang, 2015 , p. 5). The People’s Court Daily has asserted that Yu’s achievements, as the judge who settled the highest number of criminal lawsuits in her division over 27 years, can be attributed to her combination of “feminine” characteristics, such as attention to detail, and her “masculine” workaholic lifestyle.…”

Section: Chinese Judiciary and Its Gendered Constructionmentioning

confidence: 99%

Gendered Justice in China: Victim–Offender Mediation as the “Different Voice” of Female Judges

Wei

2020

Int J Offender Ther Comp Criminol

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Attempts to uncover the “different voice” of female judges through testing the statistical significance of judges’ gender in decision making have offered inconsistent results. Meanwhile, a proliferation of research suggests that such “voice” might be detected through qualitative analysis. Existing findings indicate that when female judges have discretionary power regarding case management, they will typically foster a process of settlement. Based on this information, I conducted eight months of fieldwork in China and observed 68 victim–offender mediations in four district courts. I found that the criminal division is widely perceived as a masculine setting, and female judges are accustomed to employing mediation as a preferred dispute resolution method to facilitate reconciliation between the two parties and seek civil compensation for victims. Such judicial behavior is a result of propaganda from the Supreme People’s Court and a reflection of female judges’ life and work experience. By contrast, a neglect of mediation among male judges can be identified in the same workplace. The belief that mediation is feminine and time-consuming contributes to this neglect. In addition, rape lawsuits are an exception for mediation. This explorative research not only represents one of the first efforts to reveal a “different voice” in the Chinese criminal justice system but points out a direction of research for studying the judicial behaviors of female judges worldwide.

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“…Bunun için kanal yüzeylerine pinfin, bölme ilavesi, bükülmüş bantlar, kanatçıklar ve girdap üreteçleri gibi uygulamalarla ısıl performansın artırılması hedeflenmiştir. Türbülatör etkisi gösteren bu uygulamaların, akış karışımını iyileştirerek ısı transferini artırdığı bildirilmektedir Bu nedenle, pasif yöntemler, ısı değiştiricileri, buharlaştırıcılar, kondansatörler, gaz türbini kanadı soğutma kanalları, nükleer reaktörler, güneş hava ısıtıcıları gibi pek çok mühendislik uygulamalarında tercih edilmektedir [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Sriromreun vd.…”

Section: Introductionunclassified

Investigation of Effects of Baffle Heights on Flow and Heat Transfer in a Trapezoidal Channel with Vertical Baffles

Akçay

2022

Bitlis Eren Üniversitesi Fen Bilimleri Dergisi

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Bu çalışmada, üst duvarında dik bölmeler bulunan, alt duvarı trapez şeklinde dalgalandırılmış bir kanalda farklı bölme yüksekliğinin akış ve ısı transferine etkileri nanoakışkan ve taban akışkan akışı için sayısal olarak incelenmiştir. Nanoakışkan olarak TiO2 nanopartiküllerin su içerisinde süspansiyonu kullanılmış ve nanopartikül hacim oranı, φ=%1 sabit tutulmuştur. Sayısal çalışma, Hesaplamalı Akışkanlar Dinamiği (HAD) tabanlı FLUENT 15.0 programı ile iki boyutlu gerçekleştirilmiştir. Kanalın bölmeler içeren üst yüzeyinin adyabatik olduğu kabul edilmiş ve alt trapez yüzeyi Tw=360K sabit sıcaklıkta korunmuştur. İki farklı bölme yüksekliği (t=H/2 ve t=2H/3) kullanılarak farklı Reynolds sayıları (200≤Re≤1200) için nanoakışkanın ve taban akışkanın Nusselt sayısı (Nu), sürtünme faktörü (f) ve termo-hidrolik performansı (THP) hesaplanmıştır, ayrıca çalışma bölmelerin olmadığı kanal akışı ile de karşılaştırılmıştır. Kanal içerisinde farklı parametrelerde hız ve sıcaklık görüntüleri elde edilmiştir. Sayısal sonuçlar, trapez bir kanalda bölmelerin yüksekliğine ve nanoakışkana bağlı olarak ısı transferinin önemli ölçüde iyileştiğini, ancak sürtünmenin de bir miktar arttığını göstermiştir. En yüksek termo-hidrolik performans, bölmesiz kanalda taban akışkana göre, TiO2-su nanoakışkan akışında Re=400 ve t=2H/3 bölme yüksekliğinde 1,95 olarak elde edilmiştir.

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Parametric optimization of H-type finned tube with longitudinal vortex generators by response surface model and genetic algorithm

Cited by 42 publications

References 28 publications

Parametric optimization of a stamped longitudinal vortex generator inside a circular tube of a solar water heater at low Reynolds numbers

Parametric optimization of a stamped longitudinal vortex generator inside a circular tube of a solar water heater at low Reynolds numbers

Gendered Justice in China: Victim–Offender Mediation as the “Different Voice” of Female Judges

Investigation of Effects of Baffle Heights on Flow and Heat Transfer in a Trapezoidal Channel with Vertical Baffles

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