On the use of viscous micropumps for the transport of thixotropic fluids

M. Pourjafar-Chelikdani1, M. Y. Heidari2, A. Vakili2, A. Abdollahi2, A. Mahdavi Nejad3, K. Sadeghy2
1Caspian Faculty of Engineering, College of Engineering, University of Tehran, Rezvanshahr, Iran
2School of Mechanical Engineering, Center of Excellence in Design and Optimization of Energy Systems (CEDOES), College of Engineering, University of Tehran, Tehran, Iran
3School of Engineering, Wentworth Institute of Technology, Boston, USA

Tóm tắt

A cylinder rotating in an off-center position across a microchannel is known to generate a net flow for highly viscous Newtonian fluids. The mechanism is also known to be a viable option for the transport of viscoelastic or viscoplastic fluids albeit with a slight drop in performance. In the present work, the applicability of this mechanism is numerically investigated for the transport of (inelastic) time-dependent fluids obeying the structural-based Quemada model. By numerically solving the equations of motion, it is predicted that viscous micropumps can be used for the transport of thixotropic fluids although the obtained numerical results suggest that there exists a critical thixotropy number (a dimensionless number related to the fluid’s natural time) at which the flow rate is at its lowest value. It is shown that the critical thixotropy number can be avoided from the response of the fluid by properly choosing the geometrical parameters of the device. The general conclusion is that viscous micropumps can be deemed as an efficient mechanism for the transport of thixotropic fluids in microfluidic systems provided that the thixotropy number is sufficiently small, i.e., the fluid is strongly thixotropic. The device is predicted to be more suitable for anti-thixotropic fluids.

Tài liệu tham khảo

Yang J, Wolgemuth CW, Huber G (2013) Force and torque on a cylinder rotating in a narrow gap at low Reynolds number: scaling and lubrication analyses. Phys Fluids 25:051901 Bataineh KM, Al-Nimr MA (2009) 2D Navier–Stokes simulations of microscale viscous pump with slip flow. J Fluids Eng 131:51105–51107 Sen M, Wajerski D, Gad-el-Hak M (1996) A novel pump for MEMS applications. J Fluids Eng 118:624 DeCourtye D, Sen M, Gad-el-Hak M (1998) Analysis of viscous micropumps and microturbines. Int J Comput Fluid Dynam 10:13 Yokota K, Sato K, Itoh M (2006) Model experiment, numerical simulation and theoretical analysis on the characteristics of a viscous micropump using a cylindrical rotor in a rectangular duct. JSME Int J: Ser B - Fluids Thermal Eng 49(2):393 Day RF, Stone HA (2000) Lubrication analysis and boundary integral simulations of a viscous micropump. J Fluid Mech 416:197 Matthews MT, Stokes YM (2012) Lubrication analysis and numerical simulation of the viscous micropump with slip. Int J Heat Fluid Flow 33:22 Sharatchandra MC, Sen M, Gad-el-Hak M (1997) Navier–Stokes simulations of a novel viscous pump. J Fluids Eng 119:372 Abdelgawad M, Hassan I, Esmail N, Phutthavong P (2005) Numerical investigation of multistage viscous micropump configurations. J Fluids Eng 127:734 da Silva AK, Kobayashi MH, Coimbra CFM (2007) Optimal theoretical design of 2-D microscale viscous pumps for maximum mass flow rate and minimum power consumption. Int J Heat Fluid Flow 28:526 Lu J, Ding J (2010) Flow dynamical behaviors and characteristics of aligned and staggered viscous pumps. Int J Heat Mass Transf 53:2092 Choi HI, Lee Y, Choi DH, Maeng JS (2010) Design optimization of a viscous micropump with two rotating cylinders for maximizing efficiency. J Struct Multidiscip Optim 40:537 Khozeymeh-Nezhad H, Niazmand H (2018) LBM simulation of fluid flow in a viscous micropump with non-circular rotors and RSM approach for multiple response optimization. Int J Heat Fluid Flow 71:392 Kang DJ (2014) Effects of channel curvature on the performance of viscous micropumps. J Mech Sci Technol 28:3733 Lu J, Ding J, Yang J, Yang X (2014) Steady dynamical behaviors of novel viscous pump with groove under the rotor. Int J Heat Mass Transf 73:170 Hu C, Wu W, Hu J, Yuan S (2016) Flow dynamical behavior and performance of a micro viscous pump with unequal inlet and outlet areas. Eng Appl Comput Fluid Mech 10:443 da Silva AK, Kobayashi MH, Coimbra CFM (2007) Optimal design of non-Newtonian micro-scale viscous pumps for biomedical devices. Biotechnol Bioeng 96:37–47 Zhang B, Liu X, Sun J (2016) Topology optimization design of non-Newtonian roller type viscous micropumps. Struct Multidiscip Optim 53:409–424 Taghilou B, Sobhani SMJ, Pourjafar-Chelikdani M, Mahdavi Nejad A, Ghoroghi MR, Sadeghy K (2021) On the use of viscous micropumps for transporting viscoelastic fluids in channel flows: a numerical study. J Non-Newton Fluid Mech 291:104528 Pourjafar-Chelikdani M, Lavaf A, Taghilou B, Almasi S, Kowsar S, Najafi-Astmal H, Mahdavi Nejad A, Sadeghy K (2022) On the use of viscous micropumps for the transport of yield-stress liquids in microfluidic systems. J Non-Newton Fluid Mech 308:104894 Quemada D (1998) Rheological modelling of complex fluids I. The concept of effective volume fraction revisited. Eur Phys J - Appl Phys 1:119–127 Derksen JJ, Prashant (2009) Simulations of complex flow of thixotropic liquids. J Non-Newton Fluid Mech 160:65–75 Abdelgawad M, Hassan I, Esmail N (2004) Transient behavior of the viscous micropump. Microscale Thermophys Eng 8:361 Popel AS, Enden G (1993) An analytical solution for steady flow of a Quemada fluid in a circular tube. Rheol Acta 32(4):422–426 de Souza Mendes PR (2009) Modeling the thixotropic behavior of structured fluids. J Non-Newton Fluid Mech 164:66–75