Simultaneous Effects of Slip Conditions and Wall Properties on MHD Peristaltic Flow of a Maxwell Fluid with Heat Transfer
The effects of both wall slip conditions and heat transfer on the magnetohydrodynamics (MHD) peristaltic flow of a Maxwell fluid in a porous planar channel with elastic wall properties have been studied. Mathematical formulation is based upon the modified Darcy’s law. The analytical solution has been derived for the stream function and temperature under the assumptions of small wave number.The results obtained in the analysis have been discussed numerically and explained graphically.
Peristaltic flow of blood under effect of a magnetic field in a non-uniform channels
The effect of a magnetic field on peristaltic transport of blood in a non-uniform two-dimensional channels has been investigated under zero Reynolds number with long wavelength approximation. Blood is represented by a viscous, incompressible and electrically conducting couple-stress fluid (a fluid which its particles size are taken into account, a special case of a non-Newtonian fluid). It is found that the pressure rise decreases as the couple-stress fluid parameter @c increases (i.e. small size fluid particle) and increases as the Hartmann number M increases. So the pressure rise for a couple-stress fluid (as a blood model) is greater than that for a Newtonian fluid and is smaller for a magnetohydrodynamic fluid than for a fluid without an effect of a magnetic field. Finally, the maximum pressure rise (Q=0) increases as M increases and @c decreases, and the effect of the Hartmann number M is more obvious (for the same (@[email protected]?"L)"m"a"x".) as the couple-stress parameter @c increases (Newtonian fluid).
Effects of reservoir volume on performance of pulse tube cooler.
A pulse tube cooler has the advantages of long-life and low-vibration over conventional cryocoolers such as G-M and Stirling coolers because of the absence of moving parts at low temperature. On the other hand, the combination of a reservoir and orifice is indispensable to optimize the performance of pulse tube coolers. In order to make the pulse tube cooler compact for practical applications, the volume of reservoir should be minimized. This paper analyzes the effects of the reservoir volume on the thermodynamic performance of various components in a simple orifice and a double-inlet pulse tube cooler by combining a linearized model with a thermodynamic analysis. Expressions of entropy production for those components are presented. The results show that the reservoir volume has a significant influence on the entropy production in the various components when the reservoir to pulse tube volume ratio is smaller than about 5. The ratio is important to determine the minimum reservoir volume for a pulse tube cooler. Optimum settings for a double-inlet pulse tube cooler are also discussed.