IOP PUBLISHING JOURNAL OF MICROMECHANICS AND MICROENGINEERING J. Micromech. Microeng. 19 (2009) 125013 (12pp) doi:10.1088/0960-1317/19/12/125013 Experimental and numerical analyses of micro rotary shaft pumps A Rossetti, G Pavesi and G Ardizzon Department of Mechanical Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy E-mail: antonio.rossetti@unipd.it Received 10 March 2009, in final form 21 September 2009 Published 5 November 2009 Online at stacks.iop.org/JMM/19/125013 Abstract This paper presents experimental and numerical results obtained with micro rotary shaft pumps (RSP). Impellers with a diameter of 2.5 mm, different outlet widths and blade number were coupled with semicircular volutes with different eccentricities. Experimental data for every impeller–volute couple were reported and include the flow rate, head and overall efficiency. Different rotational speeds were tested up to 24000 rpm, obtaining pressure increases up to 5.7 kPa and flow rates up to 80 ml min −1 . The non-dimensional performance was also computed obtaining the maximum head coefficient of 0.49 and the maximum flow coefficient of 0.138. Furthermore, experimental data were compared with 3D time-dependent CFD simulations. The focus of the simulation was to study the flow field structure inside the impeller and in the volute. Moreover, CFD data allowed for the calculation of the hydraulic efficiency of the pump and for the impeller to highlight the stator rotor interference influence on the pump characteristics, as well as to show the distribution of losses inside the volute. Introduction In recent years, many fields such as biology, medicine and microelectronics have relied upon the miniaturization of electromechanical systems. For many of these micro electromechanical systems (MEMS) there is a need to circulate or move fluid through macro- and micro-scale channels. Micropumps are particularly interesting devices because of their fundamental importance; every time fluid volumes need to be moved or somehow manipulated (Laser and Santiago 2004). Numerous designs are possible to meet the requirements imposed by different applications, which cover several orders of magnitude, in terms of flow rate and pressure head. Flow rates can range from a few μl min −1 , as in micro total analysis systems (μTAS), to several dl min −1 , when micro cooling applications are considered (Laser and Santiago 2004), whereas pump head can range from a few kPa up to several thousand kPa (Laser and Santiago 2004). Many different micropumps are proposed to meet this need, generally to fulfil specific applications (Nguyen and Wereley 2006). These include membrane pumps (Olsson et al 1995, Tsia and Lin 2002, Nguyen and Huang 2001, Benard et al 1998, Meng et al 2000, Gass et al 1994, Saggere et al 2000) both without check valves (Olsson et al 1995, Tsia and Lin 2002, Nguyen and Huang 2001, Benard et al 1998) and with check valves (Meng et al 2000, Gass et al 1994, Saggere et al 2000), electrohydrodynamic pumps (Richter et al 1991, Fuhr et al 1992, Ahn and Kim 1998), electrokinetic pumps (Furuya et al 1996, Zeng et al 2000), viscous pumps (Sen et al 1996, Kilani et al 2003, Blanchard et al 2005b, 2006, Haik et al 2007, Al-Halhouli et al 2008), rotary pumps (Ahn and Allen 1995, Dopper et al 1997, Chou et al 2001, Atencia and Beebe 2006), peristaltic pumps (Nguyen and Huang 2001, Mizoguchi et al 1992, Grosjean and Tai 1999, Cabuz et al 2001, Husban et al 2004, Jang and Kan 2007), ultrasonic pumps (Miyazaki et al 1991, Luginbuhl et al 1997) and several other types. Many of these micropumps are fabricated using micro fabrication technology. Non-mechanical pumps are suitable when low flow rates are requested (Nguyen and Wereley 2006), such as in biological and chemical systems, while mechanical pumps can be successfully applied when intermediate or high flow rates are involved, such as in microelectronic cooling systems (Nguyen and Wereley 2006); they are also suitable for some new applications when low flow rates are requested (Atencia and Beebe 2004, 2006). Mechanical micropumps are capable of handling a wide variety of fluids and do not require a high voltage supply, as do other non-mechanical micropumps. The rotary shaft pump (Blanchard et al 2005a, Allen and Ligrani 2006, Pavesi et al 2007, 2008) is one of the 0960-1317/09/125013+12$30.00 1 © 2009 IOP Publishing Ltd Printed in the UK