scholarly journals The role of collective elasticity on activated structural relaxation, yielding, and steady state flow in hard sphere fluids and colloidal suspensions under strong deformation

2020 ◽  
Vol 153 (19) ◽  
pp. 194502
Author(s):  
Ashesh Ghosh ◽  
Kenneth S. Schweizer
Keyword(s):  
Steady State ◽  
Structural Relaxation ◽  
Hard Sphere ◽  
Colloidal Suspensions ◽  
Steady State Flow ◽  
State Flow ◽  
Strong Deformation

scholarly journals On the Steady-State Flow and Yielding Behaviour of Lubricating Greases

Fluids ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 6 ◽  
Author(s):  
Miguel A. Delgado ◽  
Sebastien Secouard ◽  
Concepción Valencia ◽  
José M. Franco
Keyword(s):  
Steady State ◽  
Transient Flow ◽  
Colloidal Suspensions ◽  
Flow Behaviour ◽  
Shear Stresses ◽  
Steady State Flow ◽  
Shear Rates ◽  
State Flow ◽  
Constant Shear ◽  
Wide Range

Practical steady-state flow curves were obtained from different rheological tests and protocols for five lubricating greases, containing thickeners of a rather different nature, i.e., aluminum complex, lithium, lithium complex, and calcium complex soaps and polyurea. The experimental results demonstrated the difficulty to reach “real” steady-state flow conditions for these colloidal suspensions as a consequence of the strong time dependence and marked yielding behavior in a wide range of shear rates, resulting in flow instabilities such as shear banding and fracture. In order to better understand these phenomena, transient flow experiments, at constant shear rates, and creep tests, at constant shear stresses, were also carried out using controlled-strain and controlled-stress rheometers, respectively. The main objective of this work was to study the steady-state flow behaviour of lubricating greases, analyzing how the microstructural characteristics may affect the yielding flow behaviour.

Calibration 7" – Cutthroat Flume as New Size for Discharge Measurement at Free Flow Condition

2020 ◽  
Vol 38 (12A) ◽  
pp. 1783-1789
Author(s):  
Jaafar S. Matooq ◽  
Muna J. Ibraheem
Keyword(s):  
Steady State ◽  
Flow Condition ◽  
Laboratory Experiments ◽  
Free Flow ◽  
Experimental Program ◽  
Steady State Flow ◽  
Empirical Formulas ◽  
State Flow ◽  
Operation Conditions ◽  
Throat Width

 This paper aims to conduct a series of laboratory experiments in case of steady-state flow for the new size 7 ̋ throat width (not presented before) of the cutthroat flume. For this size, five different lengths were adopted 0.535, 0.46, 0.40, 0.325 and 0.27m these lengths were adopted based on the limitations of the available flume. The experimental program has been followed to investigate the hydraulic characteristic and introducing the calibrated formula for free flow application within the discharge ranged between 0.006 and 0.025 m3/s. The calibration result showed that, under suitable operation conditions, the suggested empirical formulas can accurately predict the values of discharge within an error ± 3%.

A Graphical Method for Storage Coefficient Determination from Quasi-Steady State Flow Data

1996 ◽  
Vol 27 (4) ◽  
pp. 247-254 ◽  
Author(s):  
Zekâi Şen
Keyword(s):  
Steady State ◽  
Graphical Method ◽  
Pumping Test ◽  
Quasi Steady State ◽  
Flow Data ◽  
Steady State Flow ◽  
Storage Coefficient ◽  
State Flow ◽  
Aquifer Test

A simple, approximate but practical graphical method is proposed for estimating the storage coefficient independently from the transmissivity value, provided that quasi-steady state flow data are available from a pumping test. In the past, quasi-steady state flow distance-drawdown data have been used for the determination of transmissivity only. The method is applicable to confined and leaky aquifers. The application of the method has been performed for various aquifer test data available in the groundwater literature. The results are within the practical limits of approximation compared with the unsteady state flow solutions.

Steady-State Flow Behavior of CO2 Foam

2004 ◽  
Author(s):  
J.S. Kim ◽  
Y. Dong ◽  
W.R. Rossen
Keyword(s):  
Steady State ◽  
Flow Behavior ◽  
Steady State Flow ◽  
State Flow ◽  
Co2 Foam

Dependency of Unsteady Time-Linearized Flutter Investigations on the Steady State Flow Field

2011 ◽  
Author(s):  
Michael Blocher ◽  
Markus May ◽  
Harald Schoenenborn
Keyword(s):  
Steady State ◽  
Steady State Solution ◽  
Elastic Stability ◽  
Compressor Cascade ◽  
Steady State Flow ◽  
State Flow ◽  
Flow Parameters ◽  
Pressure Distributions ◽  
German Aerospace ◽  
École Polytechnique

The influence of the steady state flow solution on the aero-elastic stability behaviour of an annular compressor cascade shall be studied in order to determine sensitivities of the aero-dynamic damping with respect to characteristic flow parameters. In this context two different flow regimes — a subsonic and a transonic case — are subject to the analysis. The pressure distributions, steady as well as unsteady, on the blade surface of the NACA3506 profile are compared to experimental data that has been gained by the Institute of Aeroelasticity of the German Aerospace Center (DLR) during several wind tunnel tests at the annular compressor cascade facility RGP-400 of the Ecole Polytechnique Fe´de´rale de Lausanne (EPFL). Whereas a certain robustness of the unsteady CFD results can be stated for the subsonic flow regime, the transonic regime proves to be very sensitive with respect to the steady state solution.

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