Electrorheological Flow Research Articles

Electro-rheological flow of seminal fluid (K-L MODEL) induced by movement of cilia in a circular conduit

The current study deals with the flow of seminal fluid through the ductus efferentes owing to electro-osmotic force and motion of cilia. The constitutive equation of semen liquid has been assumed to be described as a K-L (Kuang and Luo) fluid model. The main equations of the ciliary flow of K-L model are solved by considering the supremacy of viscous upshot over inertia influence assuming the state of long wave-length number. The analytic expressions for velocity profile, flow rate and flow impedance are derived. This is the first time to bring out to the lime light that the flow impedance is decreased and the plug core radius is enlarged with the introduction of electric force in the ciliary flow system. The effects of pertinent physiological parameters on the time-mean flow rates of rhesus monkey and human semen are thoroughly investigated. The computational mean flow rate's value over the period of time of the current mathematical model has been well matched with the corresponding experimentation values of the time-mean flow rates of rhesus monkey and humanoid semen in the path of generative and the vas deferens of the path of generative of male. Introduction of electric field into the flow ciliary system and the rheology of semen fluid described as K-L fluid model (for the values of rheological parameters of K-L fluid are considered) reduce the flow resistance, which in turn elevates the flow velocity of seminal fluid, which activates the significant and favorable changes for Oocytes getting fertilized within hours of ovulation by means of reasonable volume of semen transport into the female reproductive tract to partake a quick contact with cervical mucus and enter the cervix.

Modeling and analysis of an electrorheological flow behavior containing semiconducting graphene oxide/polyaniline composite particles

The flow behavior of electrorheological suspensions containing graphene oxide/polyaniline composite particles was reanalyzed using a model we proposed recently. The shear stress data obtained experimentally from an electrorheological fluid revealed that the structural reformation of the aligned fibers depended on the shear rate, in good agreement with the model. The static yield stress was depended quadratically on the field strength, in agreement with the predictions of the polarization model. A scaling function was used to model the yield stress behavior of the fluid over a range of electric fields, and it correctly predicted the static yield stress behavior.

A Note on the Existence and Uniqueness of Time-Periodic Electro-rheological Flows

We prove the existence and uniqueness of time-periodic motions of an electro-rheological fluid, subject to a time-periodic body force. Further if the force vanishes in its periodicity interval and if a suitable relation between the size of the force and its period holds, then the solution periodically becomes extinct.

Quasi-steady Bingham plastic analysis of an electrorheological flow mode bypassdamper with piston bleed

We present an improved experimental validation of our nonlinear quasi-steadyelectrorheological (ER) and magnetorheological damper analysis, using anidealized Bingham plastic shear flow mechanism, for the flow mode of damperoperation with leakage effect. To validate the model, a double-acting ER valve orbypass damper was designed and fabricated. Both the hydraulic cylinder and thebypass duct have cylindrical geometry, and damping forces are developed in theannular bypass via Poiseuille flow. The ER fluid damper contains a controlledamount of leakage around the piston head. The leakage allows ER fluid to flowfrom one side of the piston head to the opposite side without passing through theER bypass. For this flow mode damper, the damping coefficient, defined asthe ratio of equivalent viscous damping of the Bingham plastic material,Ceq, to the Newtonianviscous damping, C,is a function of the non-dimensional plug thickness only. The damper was testedfor varying conditions of applied electric field and frequency using a mechanicaldamper dynamometer. In this analysis, the leakage damping coefficient withincorporated leakage effects, predict the amount of energy dissipated for acomplete cycle of the piston rod. Measured force verses displacement cycles formultiple frequencies and electric fields validate the ability of the non-dimensionalgroups and the leakage damping coefficient to predict the damping levels for anER bypass damper with leakage. Based on the experimental validation of themodel using these data, the Bingham plastic analysis is shown to be an effectivetool for the analysis-based design of double-acting ER bypass dampers.

PREDICTING THE ELECTRORHEOLOGICAL BEHAVIOR OF MILK CHOCOLATE

ABSTRACTElectrorheology is the study of the effects of electric fields on the flow properties of fluids. These materials generally exhibit an increase in apparent viscosity and a greater yield stress over an unelectrified sample. The phenomenon requires an electric field and polar particles suspended in an insulating oil. A standard concentric cylinder viscometer, fitted with custom made electrical attachments, was converted into an electrorheometer. This system allowed control of DC voltage (0–450 Volts mm−1), fluid temperature (35C–40.5C), and shear rate (0.022 s−1– 8.744 s−1) while observing the resulting effects on the shear stress. Dimensional analysis was used to study the rheological response of milk chocolate when subjected to electric fields. Dimensionless groups were identified to explain the phenomena, and multiple regression analysis was used to predict the electrorheological flow behavior of milk chocolate. Over the ranges of input variables, the electric field‐induced forces dominated the rheological response over thermal forces, and a prediction equation for apparent viscosity was developed as a function of electric field strength and shear rate. This mathematical expression allows for prediction of milk chocolate rheology in the presence of an electric field.

Examination of flow behaviour of electrorheological fluids in the flow mode

The use of electrorheological (ER) fluids in hydraulic systems has been demonstrated in detailed investigations at the Institute of Fluid Power Transmission and Control (IFAS) [1]. The flow behaviour of this fluid cannot be described reliably. A detailed knowledge of this flow behaviour would enable better ER component design and produce basic information for simulation models. It is therefore important for the practical applications of ER fluids. A detailed comparison is made between existing rheological models, e.g. the Bingham model, and measured values in flow mode to confirm these models and, if possible, to define a material property constant. In addition, a simple model describing the flow behaviour of an ER fluid in the flow mode with the help of a geometrical dependent variable is presented. This variable is derived from measured values and reflects the influence of the gap height and the gap length. A comparison between this function and real measured values gives a very good agreement within the defined sphere and therefore it is a good tool for the design of electrorheological flow resistors.

Effects of coating on the behavior of electrorheological fluids in torsional flow

In this paper, we report experiments on an experimental electrorheological (ER) fluid in torsional flow. The electrorheological flow properties of the ER fluid were measured using a conventional rotational viscometer (a concentric-cylinders system). Then a torsional flow device for ER fluids was designed and constructed. The flow curves measured with this device were compared with flow curves from the viscometer. The agreement between the two devices is encouraging. The addition of a PVC foil to the surfaces of the plates has been also studied. Under AC conditions the ER effect with a homogeneous coating was smaller than that in the case of no coating, but at the same time a large reduction in the current density was measured. As soon as sections had been cut out from the foil, the ER effect increased, exceeding in some cases the effect with the uncoated plates, with no significant increase in the current density. Under DC conditions, the ER effect with a coating (irrespective of the type of coating) was zero or smaller than that in the uncoated case, and the decrease of the ER effect was always accompanied by a more than proportional decrease in electric current. This implies an increase in the ER effect on the basis of the required current density. The use of a polymer mesh to coat the plates provides an increase in the ER effect in AC and DC fields. This increase in ER effect is coupled with an increase in the current density in both fields. This suggests the idea that the polarization of the polymer mesh is responsible for some of the ER effect.

Closed Loop Controlled ER-Actuator

The results of the investigation regarding the suitability of ERF when applied in hydraulics have shown so far that constructing electrorheological flow resistors for the control of pressure and volume flow is possible in principle. One of the main advantages when using the ER-technology in hydraulic systems can be seen in the high reaction rate of the ER-effect. The investigations presented in this article document the dynamic qualities of ER-fluids by means of a practical exploitation for the control of a cylinder actuator. Due to the particular possibilities for design of ER-control resistors a compact cylinder has resulted which differs considerably from traditional cylinder actuators in its construction and dynamic behaviour.

Adaptive grids for coupled viscous flow and transport

An adaptive grid refinement and coarsening scheme in two dimensions for biquadratic elements is developed. This has been incorporated in a two-dimensional finite element program for steady and transient generalized Newtonian flow problems. Numerical results are given for Navier-Stokes and power law non-Newtonian flow calculations as well as coupled fluid flow and transport problems including free surfaces, thermocapillary flows, die swell and electro-rheological flows.