Search for: straight-microchannels
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    Numerical simulation of heat transfer in mixed electroosmotic pressure-driven flow in straight microchannels

    , Article Journal of Thermal Science and Engineering Applications ; Volume 8, Issue 2 , 2016 ; 19485085 (ISSN) Shamloo, A ; Merdasi, A ; Vatankhah, P ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2016
    This paper investigates two-dimensional, time-independent elecroosmotic pressuredriven flow generated by a direct current electric potential with asymmetrical and symmetrical zeta potential distributions along the microchannel walls. Fluid flow through the horizontal microchannel is simulated using a numerical method. Two different cases are proposed to study the effect of electric potential on the flow field. First, negative electric potential is applied on the microchannel walls. In this case, large segments with negative electric potential are initially placed on the first half of the microchannel walls with two different arrangements. Afterward, smaller segments with negative electric... 

    Parametric study on mixing process in an in-plane spiral micromixer utilizing chaotic advection

    , Article Analytica Chimica Acta ; Volume 1022 , 2018 , Pages 96-105 ; 00032670 (ISSN) Vatankhah, P ; Shamloo, A ; Sharif University of Technology
    Recent advances in the field of microfabrication have made the application of high-throughput microfluidics feasible. Mixing which is an essential part of any miniaturized standalone system remains the key challenge. This paper proposes a geometrically simple micromixer for efficient mixing for high-throughput microfluidic devices. The proposed micromixer utilizes a curved microchannel (spiral microchannel) to induce chaotic advection and enhance the mixing process. It is shown that the spiral microchannel is more efficient in comparison to a straight microchannel, mixing wise. The pressure drop in the spiral microchannel is only slightly higher than that in the straight microchannel. It is... 

    A new non-dimensional parameter to obtain the minimum mixing length in tree-like concentration gradient generators

    , Article Chemical Engineering Science ; Volume 195 , 2019 , Pages 120-126 ; 00092509 (ISSN) Rismanian, M ; Saidi, M. S ; Kashaninejad, N ; Sharif University of Technology
    Elsevier Ltd  2019
    Microfluidic-based concentration gradient generators (CGGs) have a number of applications in chemical, biological and pharmaceutical studies. Thus, precise design of the microfluidic system is crucial to maintaining the desired concentration gradient in microchannels. One of the design considerations is the length of microchannels in the structure of a CGG. A CGG with a short length fails to provide the complete diffusive mixing, while the size of the microchip would unfavorably increase by incorporating a long CGG. Considering a CGG as a tree-like structure consisting of T-shaped micromixers, the mixing process of the species at a straight microchannel has been solved analytically. Herein,... 

    Numerical investigation on the effect of external varying magnetic field on the mixing of ferrofluid with deionized water inside a microchannel for lab-on-chip systems

    , Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; 2020 Saadat, M ; Ghassemi, M ; Shafii, M. B ; Sharif University of Technology
    Taylor and Francis Inc  2020
    Energy-efficient mixing is vital for chemical and fuel processes. To this end, a flow-focusing configuration is proposed to investigate the effect of a uniform magnetic field on the mixing of a water-based ferrofluid with two streams of deionized water. An external and varying magnetic field is imposed on a straight microchannel, and the mixing between the ferrofluid and deionized waters is qualitatively and quantitatively measured. A commercial code based on the finite-element method is used, and the simulations are validated by two experimental studies in the literature. For a magnetic flux density of 10 mT, a signal frequency of 1 Hz, a duty cycle of 0.3, an inlet velocity of 500 µm/s,...