Pulsating flows of viscous fluid in flat channel for given harmonic fluctuation of flow rate

Abstract

In research work, it is pointed out the issue of a pulsating flow of a viscous incompressible fluid in a flat channel for a given harmonic fluctuation of the fluid flow rate. The study of the generation of pulsating current is used in biological mechanics, in particular, in the use of microchip systems. In addition, to ensure a constant flow of liquid, pneumatic micropumps that periodically squeeze liquid from empty volumes are widely used. In such systems, the installation of pulsating flow is shown to be economically beneficial. The transfer function of the amplitude-phase rate response is determined; with the help of these functions, the ratio of the tangential shear pressure on the channel fence to the average acceleration over the channel section is determined. In Figure 1, it can be seen that the ratio of KH = 0 of in τHC/τ0KC is close to one and α02 is less than one. If α02 takes on values greater than unity, then the ratio of to KH = 0 to τHC/τ0KC is greater than unity, and it has been shown to increase with increasing frequency of dimensionless oscillation. It was shown that in an unsteady flow of liquid, even in cases where liquid acceleration is equal to zero, it was studied that the stress on the wall of the channel exceeds its quasi-stationary value. τHC/τ0KC with the increase of the ratio KH, the increase of the parameter is explained by the fact that the change of the tensile stress on the wall advances in phases concerning the average speed along the section. Calculations determine that the non-stationary shear pressure on the channel fence increases non-monotonically with the acceleration of the liquid particle at low oscillation frequencies. The shear pressure reaches its maximum value, then decreases with increasing dimensionless oscillation rate, and asymptotically approaches the values without accelerated flow.