Search for: microgrooves
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    Optimization of microgrooves for water–solid drag reduction using genetic algorithm

    , Article Journal of Ocean Engineering and Marine Energy ; Volume 6, Issue 3 , 2020 , Pages 221-242 Abdollahzadeh, M. J ; Moosavi, A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2020
    The friction on the water–solid interfaces continues to be the most important factor for the energy loss in many marine and submarine applications. Therefore, different techniques have been developed and are available to reduce friction and, as a result, the overall cost. In the past decades, the use of structured surfaces has been given considerable attention because of their specific characteristics such as their abilities in pressure drop reduction. However, an appropriate optimization method is required to find the best surface structure. In the present study, we consider a microgrooved substrate and examine the performance of three shapes including rectangular, elliptical, and... 

    Combined effects of electric stimulation and microgrooves in cardiac tissue-on-a-chip for drug screening

    , Article Small Methods ; Volume 4, Issue 10 , 2020 Ren, L ; Zhou, X ; Nasiri, R ; Fang, J ; Jiang, X ; Wang, C ; Qu, M ; Ling, H ; Chen, Y ; Xue, Y ; Hartel, M.C ; Tebon, P ; Zhang, S ; Kim, H.-J ; Yuan, X ; Shamloo, A ; Dokmeci, M. R ; Li, S ; Khademhosseini, A ; Ahadian, S ; Sun, W ; Sharif University of Technology
    John Wiley and Sons Inc  2020
    Animal models and traditional cell cultures are essential tools for drug development. However, these platforms can show striking discrepancies in efficacy and side effects when compared to human trials. These differences can lengthen the drug development process and even lead to drug withdrawal from the market. The establishment of preclinical drug screening platforms that have higher relevancy to physiological conditions is desirable to facilitate drug development. Here, a heart-on-a-chip platform, incorporating microgrooves and electrical pulse stimulations to recapitulate the well-aligned structure and synchronous beating of cardiomyocytes (CMs) for drug screening, is reported. Each chip... 

    Heat transfer of power-law fluids under electrowetting actuation in structured microchannels

    , Article International Communications in Heat and Mass Transfer ; Volume 130 , 2022 ; 07351933 (ISSN) Izadi, R ; Merdasi, A ; Moosavi, A ; Sharif University of Technology
    Elsevier Ltd  2022
    The dynamics and heat transfer performance of droplets play an important role in electrowetting systems. Contrary to the growing trend towards non-Newtonian fluids in electrotechnical systems, most researchers have focused on Newtonian fluids. In the current study, the interface is tracked by the phase-field method and afterwards, the numerical model is confirmed by comparing the results obtained from previous experimental and theoretical works. Several parameters such as power-law index and contact angle are analyzed. Furthermore, the dynamics and heat transfer of the droplets on chemically or topographically structured substrates in the presence of electrowetting are examined. It has been... 

    Numerical simulation of drag reduction in microgrooved substrates using lattice-boltzmann method

    , Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 141, Issue 7 , 2019 ; 00982202 (ISSN) Asadzadeh, H ; Moosavi, A ; Etemadi, A ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2019
    We study drag reduction of a uniform flow over a flat surface due to a series of rectangular microgrooves created on the surface. The results reveal that making grooves on the surface usually leads to the generation of secondary vortices inside the grooves that, in turn, decreases the friction drag force and increases the pressure drag force. By increasing the thickness of the grooves to the thickness of the obstacle, the pressure drag increases due to the enhancement of the generated vortices and the occurrence of separation phenomenon and the friction drag reduces due to a decrease of the velocity gradient on the surface. In addition, by increasing the grooves depth ratio, the pressure... 

    Pressure drop reduction of power-law fluids in hydrophobic microgrooved channels

    , Article Physics of Fluids ; Volume 31, Issue 7 , 2019 ; 10706631 (ISSN) Javaherchian, J ; Moosavi, A ; Sharif University of Technology
    American Institute of Physics Inc  2019
    Using hydrophobic surfaces is one of the efficient methods to preserve energy in fluid transfer systems. However, the studies have been concentrated on Newtonian fluids despite the wide applications of non-Newtonian fluids in daily life and many industries such as the biological, foodstuff, chemical, petroleum, cosmetic, and lab on a chip fields. In this study, we consider power-law fluids as a typical example of non-Newtonian fluids and investigate the effect of hydrophobic microgrooves on the pressure drop in channels by utilizing the phase field method. We demonstrate that the optimum size of the rectangular microgrooves in which the maximum pressure drop reduction (PDR) happens for both...