A Computational Analysis for Active Flow and Pressure Control Using Moving Roller Peristalsis

Abstract

Peristaltic motion arises in many physiological, medical, pharmaceutical and industrial processes. Control of the fluid volume rate and pressure is crucial for pumping applications, such as the infusion of intravenous liquid drugs, blood transportation, etc. In this study, a simulation of peristaltic flow is presented in which occlusion is imposed by pairs of circular rollers that squeeze a deformable channel connected to a reservoir with constant fluid pressure. Naturally, this kind of flow is laminar; hence, the computation occurred in this context. The effect of the number and speed of the pairs of rollers, as well as that of the intrapair roller gap, is investigated. Non-Newtonian fluids are considered, and the effect of the shear-thinning behavior degree is examined. The volumetric flow rate is found to increase with an increase in the number of rollers or in the relative occlusion. A reduction in the Bird–Carreau power index resulted in a small reduction in transport efficiency. The characteristic of the pumping was computed, i.e., the induced pressure as a function of the fluid volume rate. A strong positive correlation exists between relative occlusion and induced pressure. Shear-thinning behavior significantly decreases the developed pressure compared to Newtonian fluids. The immersed boundary method on curvilinear coordinates is adapted and validated for non-Newtonian fluids.

Multivariate Peristalsis in a Straight Rectangular Duct for Carreau Fluids

“…With reference to relevant experiments, computational simulations are performed for carboxymethyl-cellulose aqueous solution at 1.5% w/w with 0.1 M NaCl and M w = 2.5 • 10 5 g/mol (CMC 1.5%) [37]. The shape and size of the pulses and the dimensions of the straight duct are also chosen in accordance with the existing literature [18,35]. Consequently, the values of the fluid properties and of the geometric dimensions of the setting are opted for as in Table 1.…”

“…Consequently, the values of the fluid properties and of the geometric dimensions of the setting are opted for as in Table 1. Similarly, the parameters of the analysis such as the wave speed and the relative occlusion are instantiated with values for which previous research has been conducted [18,35,38]. The single cylindrical segment contraction wave in Figure 1 is described in the computational domain by the equation…”

“…This value increases in a concave manner above c for more segments. Streamwise velocity component magnitude for multiple squeezing cylindrical segments pulse at the middle of the width and y = 0.05 mm for the case with no slip side walls (NSSWs) and for the case with slip side walls (SSWs) [35]. The relative occlusion is RO = 0.6, the peristaltic wave speed is c = 5 mm s , the power index is n = 1 and the length is L = 180 mm.…”

“…The curvilinear immersed boundary method is being implemented for the simulation of incompressible internal and external flows of Newtonian and non-Newtonian fluids in a variety of laminar and turbulent flow applications with either steady or moving boundaries [28][29][30][31][32]. Asgharzedeh and Borazjani, by introducing an analytical Jacobian for Newton-Krylov methods, simulate the Taylor-Green vortex, the horizontal oscillations of a cylinder initially at rest and flow in a 90 • bend [33].…”

“…The results of the endeavor contribute to our knowledge on peristalsis in a rectilinear duct of fixed width with steady walls for this category of generalized Newtonian fluids and the respective medical and industrial applications. Continuing a line of research on the setting [16,[18][19][20]35], a monothetic analysis of the peristaltic characteristic quantities is presented. The need for this approach is evident from the significant amount of resources demanded for dealing with a singular instance of the problem in combination with the multiple factors examined, leading to the adverse effects of the curse of dimensionality.…”