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In present paper, a numerical study is performed for analysis of effects of geometrical and operational parameters of viscous micropump with the approach to Entropy Generation Minimization by Lattice Boltzmann Method. In study of effect of change in the geometric parameter L and operational parameters ∆P*, it was found that in all ∆P*s, two range of L=1.2 - 1.6 and L=4.4 - 4.8 at EGM viewpoint and two range of L=1.1 - 1.6 and L=4.4 - 4.9 at the minimum power of rotors viewpoint are introduced as optimum ranges. Due to the full overlap of optimum ranges at the EGM viewpoint with the minimum power of rotors viewpoint, the same range mentioned in the EGM viewpoint is selected as the optimal range. Results of the effect of change in the geometric parameter L and operational parameters Re showed that in all Res, two range of L=1.1 - 1.5 and L=4.5 - 4.9 at the EGM viewpoint and two range of L=1.2 - 1.6 and L=4.4 - 4.8 at the minimum power of rotors viewpoint are introduced as optimum ranges. Therefore, the common range of these viewpoint namely L=1.2 - 1.5 and L=4.5 - 4.8 can be selected as the most optimal range. Regarding the effect of change in the geometric parameter ε and operational parameters Re and ∆P* is determined in all Res and ∆P*s, the range of ε = 0.1 – 0.5 is selected as optimum range in the EGM viewpoint and the minimum power of rotors viewpoint.

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In the present paper, a numerical study is performed for analysis of 3D effects of geometrical parameters namely microchannel depth, eccentricity and sizes of rotors and operational parameter namely pressure difference on flow flux and efficiency by LBM. In investigation of simultaneously variation effect of geometrical parameters namely rotors eccentricity and microchannel depth is observed in all depths, increasing the eccentricity, both flow flux and efficiency increased. Also, in a constant eccentricity both flow flux and efficiency increased. In the next investigation that simultaneously effect of geometrical parameters namely rotors sizes and microchannel depth is discussed determined that in all depths, decreasing the rotors sizes, flow flux decreased. But for efficiency, it became less in the lower depths and increasing depth the efficiency increased. In final, the effects of operational parameter of pressure difference and geometrical parameter of microchannel depth on flow flux and efficiency has been studied. As the results show, increasing the pressure difference, flow flux linearly decreased so that it became zero at the certain pressure. Moreover, efficiency variations vs. pressure difference parabolically is observed.