scholarly journals Frequency-Dependent Streaming Potential in a Porous Transducer-Based Angular Accelerometer

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1780
Author(s):  
Li Ming ◽  
Meiling Wang ◽  
Ke Ning
Keyword(s):  
Steady State ◽  
Streaming Potential ◽  
Low Frequency ◽  
Fluid Flows ◽  
Surface Conductance ◽  
Frequency Dependent ◽  
Transient Model ◽  
Angular Accelerometer ◽  
Proposed Model ◽  
High Consistency

This paper presents a transient model of streaming potential generated when fluid flows through a porous transducer, which is sintered by glass microspheres and embedded in the circular tube of a liquid circular angular accelerometer (LCAA). The streaming potential coupling coefficient (SPC) is used to characterize this proposed transient model by combining a capillary bundle model of a porous transducer with a modified Packard’s model. The modified Packard’s model is developed with the consideration of surface conductance. The frequency-dependent streaming potential is investigated to analyze the effect of structure parameters of porous media and the properties of the fluid, including particle size distribution, zeta potential, surface conductance, pH, and solution conductivity. The results show that the diameter of microspheres not only affects bandwidth and transient response, but also influences the low-frequency gain. In addition, the properties of the fluid can influence the low-frequency gain. Experiments are actualized to measure the steady-state value of permeability and SPC for seven types of porous transducers. Experimental results possess high consistency, which verify that the proposed model can be utilized to optimize the transient and steady-state performance of the system effectively.

scholarly journals Frequency-Dependent Streaming Potential of Porous Media—Part 2: Experimental Measurement of Unconsolidated Materials

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
P. W. J. Glover ◽  
E. Walker ◽  
J. Ruel ◽  
E. Tardif
Keyword(s):  
Porous Media ◽  
Steady State ◽  
Capillary Tube ◽  
Streaming Potential ◽  
Low Frequency ◽  
Theoretical Models ◽  
Potential Coefficient ◽  
Frequency Dependent ◽  
New Apparatus ◽  
Good Agreement

Frequency-dependent streaming potential coefficient measurements have been made upon Ottawa sand and glass bead packs using a new apparatus that is based on an electromagnetic drive. The apparatus operates in the range 1 Hz to 1 kHz with samples of 25.4 mm diameter up to 150 mm long. The results have been analysed using theoretical models that are either (i) based upon vibrational mechanics, (ii) treat the geological material as a bundle of capillary tubes, or (iii) treat the material as a porous medium. The best fit was provided by the Pride model and its simplification, which is satisfying as this model was conceived for porous media rather than capillary tube bundles. Values for the transition frequency were derived from each of the models for each sample and were found to be in good agreement with those expected from the independently measured effective pore radius of each material. The fit to the Pride model for all four samples was also found to be consistent with the independently measured steady-state permeability, while the value of the streaming potential coefficient in the low-frequency limit was found to be in good agreement with other steady-state streaming potential coefficient data.

Transient Response of Inductrack Systems for Maglev Transport: Part II—Solution and Dynamic Analysis

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Ruiyang Wang ◽  
Bingen Yang
Keyword(s):  
Steady State ◽  
Dynamic Analysis ◽  
Transient Response ◽  
Numerical Procedure ◽  
Steady State Response ◽  
Governing Equations ◽  
Transient Model ◽  
State Response ◽  
Proposed Model ◽  
Non Linear

Abstract In Part I of this two-part paper, a new benchmark transient model of Inductrack systems is developed. In this Part II, the proposed model, which is governed by a set of non-linear integro-differential governing equations, is used to predict the dynamic response of Inductrack systems. In the development, a state-space representation of the non-linear governing equations is established and a numerical procedure with a specific moving circuit window for transient solutions is designed. The dynamic analysis of Inductrack systems with the proposed model has two major tasks. First, the proposed model is validated through comparison with the noted steady-state results in the literature. Second, the transient response of an Inductrack system is simulated and analyzed in several typical dynamic scenarios. The steady-state response results predicted by the new model agree with those obtained in the previous studies. On the other hand, the transient response simulation results reveal that an ideal steady-state response can hardly exist in those investigated dynamic scenarios. It is believed that the newly developed transient model provides a useful tool for dynamic analysis of Inductrack systems and for in-depth understanding of the complicated electro-magneto-mechanical interactions in this type of dynamic systems.

scholarly journals Frequency-Dependent Streaming Potentials: A Review

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
L. Jouniaux ◽  
C. Bordes
Keyword(s):  
High Frequency ◽  
Streaming Potential ◽  
Low Frequency ◽  
Transition Frequency ◽  
Formation Factor ◽  
Potential Coefficient ◽  
Frequency Dependent ◽  
Streaming Potentials ◽  
Dynamic Permeability ◽  
Inertial Flow

The interpretation of seismoelectric observations involves the dynamic electrokinetic coupling, which is related to the streaming potential coefficient. We describe the different models of the frequency-dependent streaming potential, mainly Packard's and Pride's model. We compare the transition frequency separating low-frequency viscous flow and high-frequency inertial flow, for dynamic permeability and dynamic streaming potential. We show that the transition frequency, on a various collection of samples for which both formation factor and permeability are measured, is predicted to depend on the permeability as inversely proportional to the permeability. We review the experimental setups built to be able to perform dynamic measurements. And we present some measurements and calculations of the dynamic streaming potential.

The Determination of Electrokinetic Coupling-Coefficient and Zeta Potential of Rock Samples by Electrokinetic Measurements

2012 ◽  
Vol 516-517 ◽  
pp. 1870-1873 ◽  
Author(s):  
Jun Wang ◽  
Heng Shan Hu
Keyword(s):  
Zeta Potential ◽  
Coupling Coefficient ◽  
Streaming Potential ◽  
Potential Method ◽  
Surface Conductivity ◽  
Reliable Estimate ◽  
Surface Conductance ◽  
Streaming Current ◽  
Low Concentrations

The electrokinetic effects are important in the understanding of electric properties in porous medium. In this study, the streaming potential and streaming current of saturated samples are measured at different concentrations, then three methods are applied to obtain the zeta-potential and electrokinetic coupling coefficient. The study shows that the results obtained from streaming potential and streaming current methods agree well with each other, but the results obtained from simplified streaming potential method become seriously inaccurate at low concentrations due to the influence of surface conductance. This experimental study also provides a reliable estimate of the surface conductivity and its contribution to zeta-potential at given concentrations.

Modelling And Simulation of Topical Drug Diffusion in The Dermal Layer of Human Body

2021 ◽  
Vol 86 (2) ◽  
pp. 39-49
Author(s):  
Sudi Mungkasi
Keyword(s):  
Steady State ◽  
Human Body ◽  
Diffusion Problem ◽  
State Condition ◽  
Unsteady State ◽  
Steady State Condition ◽  
Drug Diffusion ◽  
Dermal Layer ◽  
Drug Concentrations ◽  
Proposed Model

We consider the problem of drug diffusion in the dermal layer of human body. Two existing mathematical models of the drug diffusion problem are recalled. We obtain that the existing models lead to inconsistent equations for the steady state condition. We also obtain that solutions to the existing models are unrealistic for some cases of the unsteady state condition, because negative drug concentrations occur due to the inappropriate assumption of the model. Therefore, in this paper, we propose a modified mathematical model, so that the model is consistent, and the solution is nonnegative for both steady and unsteady state conditions of the drug diffusion problem in the dermal layer of human body. For the steady state condition, the exact solution to the proposed model is given. For unsteady state condition, we use a finite difference method for solving the models numerically, where the discretisation is centred in space and forward in time. Simulation results confirm that our proposed model and method preserve the non-negativity of the solution to the problem, so the solution is more realistic than that of the old model.

Prediction of Deswirled Radial Inflow in Rotating Cavities With Hysteresis

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
David May ◽  
John W. Chew ◽  
Timothy J. Scanlon
Keyword(s):  
Steady State ◽  
Flow Characteristic ◽  
Steady State Solution ◽  
Negative Resistance ◽  
Operating Conditions ◽  
Operating Characteristics ◽  
Transient Model ◽  
Rotating Cavity ◽  
1D Model ◽  
Flow Effects

Deswirl nozzles are sometimes used in turbomachinery to reduce the pressure drop when air is drawn radially inwards through a rotating cavity. However, this can lead to nonunique steady state solutions with operating conditions achieved depending on how the steady point is approached. In the present study, a novel transient, 1D model of flow in a rotating cavity has been created. The model was validated for two distinct cases: a smooth rectangular cavity and an engine-representative case. The transient model reproduced experimentally observed hysteresis, discontinuity in operating characteristics, and regions where no steady-state solution could be found. In the case of the engine-representative rig, part of the flow characteristic could not be obtained in testing. This was determined to be due to the interaction of the negative resistance region of the vortex and the flow-modulating valve characteristic. Measures that allow the full capture of the flow characteristic in rig testing are identified. These results show that inclusion of transient rotating flow effects can be important in turbomachinery air systems modeling. To the authors' knowledge, this is the first model to capture these effects.

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