Heat and Mass Transfer最新文献

{"title":"Thermal enhancement of a constructal PCM cylindrical heat sink used for prosthetic cooling application","authors":"Hind Dhia’a Ridha, Akram W. Ezzat, Hameed B. Mahood","doi":"10.1007/s00231-024-03500-0","DOIUrl":"https://doi.org/10.1007/s00231-024-03500-0","url":null,"abstract":"<p>Amputees often experience high temperatures between the amputated limb and the prosthetic socket, necessitating the use of cooling devices to mitigate this issue. However, challenges arise with the location and size of conventional heat sinks. This research proposes a novel heat sink utilising a phase change material (PCM) to dissipate heat. The leg was chosen as the site for the heat sink, designed in a cylindrical shape. Coolant flow pipes were arranged in a branched configuration inspired by constructal theory, constrained by the dimensions of the artificial leg. The degrees of freedom for the constructal design are branches akin to arterial and venous branching, aiming to minimise pressure drop. Four heat sinks with varying degrees of branching were compared based on temperature reduction, heat dissipation, pressure drop, phase change material melting capacity, and operational efficiency. The cylindrical heat sink measures 50 mm in diameter and 300 mm in length. Ice was employed as the PCM, with water served as the working fluid. The working fluid's temperature and flow rate were maintained at 40 °C and 0.2 L/min, respectively. The experimental work was prepared to validate the theoretical model. The study revealed that the proposed heat sink design, with increased branching, led to a significant temperature reduction, achieving up to 39.62%. Moreover, heat dissipation increased by 236% compared to a single-tube heat sink. The use of branched pipes resulted in a manageable increase in pressure drop, peaking at 39.9 Pa, well within pump specifications, while markedly enhancing heat dissipation. The melting time of the PCM and the melting area increased as the number of branches of the heat sink increased. Ultimately, applying constructal theory in heat sink design for PCM demonstrated its superior performance within spatial constraints, providing a promising solution for prosthetic cooling.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of heat flow from the cylinder sidewalls on thermocapillary droplet flow in a vibrating fluid: 3D study","authors":"Yousuf Alhendal, Sara Touzani","doi":"10.1007/s00231-024-03499-4","DOIUrl":"https://doi.org/10.1007/s00231-024-03499-4","url":null,"abstract":"<p>The thermocapillary motion of droplet in a vibrating fluid in a cylinder heated from the top and sides and cooled from the bottom is studied, using a three-dimensional computational fluid dynamics (CFD) model based on volume of fluid (VOF) created with Ansys-Fluent software. The outcomes support the accuracy of the Marangoni phenomenon and are in line with data published in literature. The behavior of the drop is not only impacted by the temperature difference between the top and bottom, but also by heated side surfaces and mostly by vibration. Different flow patterns are observed which directly impact the droplet’s arrival time. The results proof that the neglected frequency and amplitudes of vibration in the presence of gravity have a significant and evident impact on the behavior of fluids in a zero-gravity environment. The change of vessel height also has a significant influence especially on the host fluid properties.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141746427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CFD and ANN analyses for the evaluation of the heat transfer characteristics of a rectangular microchannel heat sink with various cylindrical pin-fins","authors":"Mahdi Tabatabaei Malazi, Kenan Kaya, Andaç Batur Çolak, Ahmet Selim Dalkılıç","doi":"10.1007/s00231-024-03496-7","DOIUrl":"https://doi.org/10.1007/s00231-024-03496-7","url":null,"abstract":"<p>Electrical equipment extensively uses Microchannels (MCs) for cooling. Due to their complexity, it is challenging to evaluate the features of the fluid flow and heat transfer processes in MC pin-fin heat sinks. Numerical approaches have been frequently employed in MC design to enhance efficiency. Machine learning methods have recently enabled the assessment of flow and heat transfer research in these devices. In this study, numerical calculations have been made to obtain outlet fluid temperature, the average Nusselt number, and pressure drop, using the computational fluid dynamics (CFD) software, ANSYS Fluent. Previous experimental work validates the numerical model by examining the average Nusselt number and the apparent friction factor. Three distinct ratios of fin spacing to fin diameter (<i>l</i>/<i>d</i> = 2, 4, and 6) and five different values of Reynolds number (Re = 50, 75, 100, 125, and 150) are considered. A constant ratio of fin height to channel height (h<i>/H</i> = 0.25) is maintained, and the inlet fluid temperature is set to 291.15, 294.15, 297.15, and 300.15 K. Numerical calculations have been conducted for cases of uniform and non-uniform heating, where bottom wall temperatures of 323.15 K and 317.15 K were considered, respectively, for a fixed fin surface temperature of 323.15 K. Using the results of the numerical simulations, a multi-layer perceptron (MLP)-structured artificial neural network (ANN) is trained. The Levenberg-Marquardt (LM) training method is employed in the hidden layer, using 17 neurons for the training procedure. The results of the numerical simulations show that the average Nusselt number increases linearly with the Reynolds number, except for the non-uniform heating case of Re = 50. The average Nusselt number and pressure drop are inversely proportional to fin spacing for all cases. There is also a linear increase in pressure drop with the Reynolds number, since the flow regime considered in this study is laminar. The ANN model predicts the outlet fluid temperature, the average Nusselt number, and the pressure drop, with variation rates of -0.0027%, -0.075%, and − 0.0004%, respectively.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141610708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat transfer characteristics of cascade phase change energy storage composite pipeline","authors":"Ying Xu, Chenguang Wei, Qiong Wang, Chuan Ma, YuQi Zhang, XiaoYan Liu","doi":"10.1007/s00231-024-03497-6","DOIUrl":"https://doi.org/10.1007/s00231-024-03497-6","url":null,"abstract":"<p>In the context of dual-carbon strategy, the insulation performance of the gathering and transportation pipeline affects the safety gathering and energy saving management in the oilfield production process. PCM has the characteristics of phase change energy storage and heat release, combining it with the gathering and transmission pipeline not only improves the insulation performance of collecting and transporting pipes, but also extends the safe shut time during the shutdown. Proposed a thermal model of a PCM-based composite energy storage pipeline combining the character of phase transformation between PCM and crude oil has been established. The heat preservation performance of the combined energy storage pipeline was evaluated by numerical simulation.This paper analyses the heat transfer performance of complex energy storage pipes, and considers the influence of natural convection and variable temperature zone on insulation performance.On this basis, the structure design of cascade phase transition was proposed, the optimized cascading composite pipe was presented, and the performance of different insulation structures was compared.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141588620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel investigation on single-loop pulsating heat pipe filling with hybrid nanofluids: numerical and experimental","authors":"Prem shanker yadav, Jitendra sharma, Mohd Hussain, Imran ahmed Khan, Kartik Goyal, Samer Fikry Ahmed","doi":"10.1007/s00231-024-03495-8","DOIUrl":"https://doi.org/10.1007/s00231-024-03495-8","url":null,"abstract":"<p>Pulsating heat pipes (PHPs) employ to multiphase heat transfer between condensers and evaporators. The efficacy of PHP is predominantly contingent upon the thermos-physical property exhibited by its working fluid. The exergy analysis of evaporator, adiabatic and condenser system were performed to evaluate the efficiency and sustainability of energy conversion processes, it was also seen that exergy loss of condenser was 1.01% higher than evaporator. Further, 2-D numerical simulation of a cryogenic pulsating heat pipe (CPHP) was conducted and also numerical and experimental simulation was conducted, where simulation results agreed with experimental results with 10% similarity. The simulation employs the volume of fluid (VOF) model to capture the dynamics of two-phase liquid–vapor flow within the CPHP employing liquid acetone – Al₂O₃ as the working fluid. The diameter of the single turn is systematically varied, ranging from 1 mm to 2.5 mm, while maintaining the filling ratio (FR) within the range of 25% to 75%. The evaporator temperature is adjusted within the span of 85 K to 115 K. The PHP exhibited best thermal performance at inner diameter of 2 mm among (1, 1.5, 2, 2.5 mm) and filling ratio of 55% among (25%, 45%, 55%, 65% and 75%).</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of a method to decrease water consumption and enhance productivity in wet cooling towers using dynamic time-related modeling for industrial experimental applications","authors":"Leila Seidabadi, Hossein Ghadamian, Mohammad Jafari, Masoud Mardani, Seyed M. K. Sadr","doi":"10.1007/s00231-024-03494-9","DOIUrl":"https://doi.org/10.1007/s00231-024-03494-9","url":null,"abstract":"<p>This research examines the water and energy performance in wet cooling towers and identifies methods for enhancing efficiency and minimizing water and energy consumption by exploring methods to enhance system performance. A three-dimensional transient model, developed using MATLAB's open-source code software, was utilized to simulate the cooling tower's behaviour under various operating conditions. This research focuses on precise simulation of cooling tower behavior and demand modeling aided by regression. The model's accuracy was validated through experimental measurements in diverse environmental conditions. The key parameter and performance that is investigated in this paper is the temperature profile of the cooling tower, in which the performance algorithm and proposed methodologies are anchored in the operational temperature. The experimental results led to operational solutions for enhancing cooling tower performance. For winter conditions, the recommended action involves closing the upper part of the cooling tower and activating the two side fans. Specific approaches are suggested for mid-season and summer scenarios, focusing on make-up water consumption and ambient air temperature control, respectively. In addition, results indicated a close alignment between the model and the actual system, with discrepancies of less than 2% in energy consumption and 5% in water consumption. Analysis of proposed productivity enhancements and changes in supply policies indicated significant potential for energy and water conservation in wet cooling towers. Implementing these solutions could lead to an estimated annual reduction of 44% in water consumption and 4.2% in energy consumption.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation of air jet impingement cooling in car radiator with hollow cone nozzle plate spacing using nanofluids","authors":"P. Venkataramana, V. Mani Kumar, N. Raghu ram, Siva Sankara Babu Chinka","doi":"10.1007/s00231-024-03493-w","DOIUrl":"https://doi.org/10.1007/s00231-024-03493-w","url":null,"abstract":"<p>Water is an emerging heat transfer fluid with great promise for thermal engineering because of its heat transfer coefficients. However, much more must be done with the fluid that transmits heat to make the system more effective in handling heat. Nanoparticle cooling fluid speeds up the movement of heat through the car radiator and makes it possible to make it smaller altogether. In the present study, to examine heat transfer characteristics of nanofluids of Deionized (DI) water and Ethylene glycol (60:40). Four different concentrations of nanofluids were prepared by mixing 0.05 to 0.3 Vol. % of nanofluids with a mixture of DI water and Ethylene glycol (EG). The studies were carried out by varying coolant from 3 to 15 LPM while keeping the airspeed at a mean of 5 m/s. The airflow velocity towards the radiator is continually maintained at a median of 5 m/s. The k-type thermocouple monitors the cooling outlet’s temperature and a comparative study of the thermal conductivity of experimental results with machine learning. The results show that the DI water had a lower thermal conductivity of 0.891 W/m K than the EG nanofluid, which had a thermal conductivity of 0.946 W/m K. The EG nanofluid showed a more significant heat transfer coefficient of 36384.41 W/m² K than the DI water. The viscosity of the nanofluid increases as the concentration of nanofluid in the DI water increases and decreases as the temperature rises.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental assessment of thermohydraulic performance on counter flow impinging air solar heater integrated with arc shaped roughness","authors":"P. Michael Joseph Stalin, Murugesan Palaniappan, S. Karthikeyan, R. Ramkumar, B. Prabu, Gaddam Kalyani","doi":"10.1007/s00231-024-03492-x","DOIUrl":"https://doi.org/10.1007/s00231-024-03492-x","url":null,"abstract":"<p>The aim of this research is to conduct an experiment that will evaluate the effect of combining of counter flow air-impinging arrangement and an arc-shaped turbulators over the absorber plate of solar heater. This combination is intended to improve the thermohydraulic performance of the solar air heater. The parameters such as energy transfer and frictional factor are studied at flow Reynolds number varies from 18,000 to 3600, and the influence of a hole jet bore ratio from 0.0430 to 0.109 is considered. At the optimal hole jet bore ratio of 0.0650, the thermo-hydraulic achievement parameter has a value of 1.75, which is the greatest possible value can be attained. When compared to multi-pass V and multiple V roughened solar air heaters based on the THAP, the current work is improved the performance by 55.3 and 32.9%, respectively. Such comparisons clearly demonstrate the superiority of the present work. Furthermore, a relationship is shown between the jet hole bore ratio and the thermohydraulic performance measure, with a maximum divergence of 10%.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hygroscopic study of Moroccan Apricot varieties under isothermal conditions for a better conservation","authors":"Mohamed Rida Jeddi, Bouchaib Jamal, Younes Bahammou, Ali Idlimam, Mohammed Boukendil, Lahcen El Moutaouakil","doi":"10.1007/s00231-024-03488-7","DOIUrl":"https://doi.org/10.1007/s00231-024-03488-7","url":null,"abstract":"<p>Apricots offer diverse health benefits, making them a valuable component of an attractive diet. In addition to ensuring the physicochemical and microbiological stability during storage and the year-round availability of this nutrient-dense fruit, apricot preservation, especially through sorption isotherm processes, also considers economic, nutritional, and environmental factors. In the same context, this study explores the analysis of two common apricot cultivars in Morocco. The primary objective is to determine the optimal conditions for storing and conserving the investigated products using the standard gravimetric static method at 30 °C, 40 °C, and 50 °C—six one-liter glass jars with insulated lids made up the experimental set-up. A fourth of the glass jar was filled with a saturated salt solution. Weighing 0.100 g (±0.001) g for adsorption and 0.200 g (±0.001) g for desorption, duplicate samples were precisely weighed and put into the glass jars. The outcomes revealed that the adsorption-desorption isotherms for all samples conformed to the characteristic Type II sigmoid pattern. The ideal water activity values to preserve “Aurora” and “Carmen” are 0.36 and 0.38, respectively. It was determined that the best model to describe the sorption curves of “Aurora” and “Carmen” was LESPAM. Analysis of the adsorption-desorption data aimed to determine the moisture content of the monolayer (ranging from 3.4 to 9.7%) and examine the properties of sorbed water within their porous structures and surfaces.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applications of pulsating heat pipe (PHP) as an efficient heat transfer device: a review of recent developments","authors":"Mantri Sandeep Kumar, Satyanand Abraham","doi":"10.1007/s00231-024-03491-y","DOIUrl":"https://doi.org/10.1007/s00231-024-03491-y","url":null,"abstract":"","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141359190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}