Hydrodynamic flow stability of a fluid with a power-law rheological behavior in a channel with elastic walls

1973 ◽  
Vol 24 (6) ◽  
pp. 767-769
Author(s):  
L. K. Martinson ◽  
K. B. Pavlov ◽  
S. L. Simkhovich
Keyword(s):  
Power Law ◽  
Rheological Behavior ◽  
Flow Stability ◽  
Hydrodynamic Flow ◽  
Elastic Walls

Effects of Formulation and Temperature on the Rheological Behavior of Nitroguanidine-Based Propellants

2018 ◽  
Vol 917 ◽  
pp. 262-268
Author(s):  
Wan Wu Shen ◽  
Feng Qiang Nan ◽  
Chun Jiu Zhu ◽  
Jun Hui Lu
Keyword(s):  
Power Law ◽  
Rheological Behavior ◽  
Main Process ◽  
Solvent Ratio ◽  
Power Law Model ◽  
Key Factors ◽  
Technological Parameters ◽  
Cross Model ◽  
Rheological Test

The rheological properties of propellant are several key factors in the process design, which affect the quality of propellant processing that determines the weapon's performance. The main technological parameters influencing the quality of nitroguanidine-based propellant are nitroguanidine (NGu) content, solvent ratio and temperature. Rheological test of the propellant dough was carried out by using capillary rheometer. The effects of these main process parameters on the shear stress and shear viscosity of the propellant during the rheological process were discussed. Power law model, modified Bingham model and Cross model were used to fit the rheological data. The results show that Power law model is better than the other two models, explaining Power law model can be used as the constitutive equation to describe the actual rheological behavior of the propellant extrusion moulding more accurately.

scholarly journals Determination of Rheological Parameters from Measurements on a Viscometer with Coaxial Cylinders – Choice of the Reference Radius

10.14311/892 ◽  
2006 ◽  
Vol 46 (6) ◽  
Author(s):  
F. Rieger
Keyword(s):  
Experimental Data ◽  
Power Law ◽  
Rheological Behavior ◽  
Experimental Results ◽  
Rheological Parameters ◽  
Concentrated Suspensions ◽  
Rotational Viscometer ◽  
Coaxial Cylinders

Knowledge about rheological behavior is necessary in engineering calculations for equipment used for processing concentrated suspensions and polymers. Power-law and Bingham models are often used for evaluating the experimental data. This paper proposes the reference radius to which experimental results obtained by measurements on a rotational viscometer with coaxial cylinders should be related. 

scholarly journals A Rheological Model for Cupuassu (Theobroma grandiflorum) Pulp at Different Concentrations and Temperatures

2013 ◽  
Vol 9 (4) ◽  
pp. 353-363
Author(s):  
Modesto Antonio Chaves ◽  
Fátima Baptistia ◽  
Jadir Noqueira da Silva ◽  
Luciano Rodrigues ◽  
Arianne Dantas Viana
Keyword(s):  
Shear Stress ◽  
Regression Analysis ◽  
Power Law ◽  
Rheological Behavior ◽  
Polynomial Regression ◽  
Soluble Solids ◽  
Concentric Cylinder ◽  
Theobroma Grandiflorum ◽  
Pulp Temperature ◽  
Independent Variable

AbstractThis work was made aiming at studying the best model for the rheological properties of Cupuassu (Theobroma grandiflorum, Schum) pulps with 14 (in nature), 17, 19, 23 and 25°Brix of total soluble solids (TSS) which were measured at 20, 30, 40, 50 and 60°C temperature using a concentric cylinder rheometer. The results were adjusted to the following nine models: Ostwald-de-Waele (power law), Bingham, Casson, Generalized Casson, Heinz–Casson, Herschel–Bulkley, Mizrahi–Berk, Schulmann–Haroske–Reher and Windhab. The parameters of the best model were correlated with pulp temperature and TSS by polynomial regression analysis and were kept in the regression equation only those parameters that contributed more than 1% to the variation of the independent variable. The results indicate that the rheological behavior of Cupuassu pulp in different concentrations and temperatures can be modeled by the Windhab model, although other models can be used in a narrower band of shear stress.

scholarly journals Empirical Estimation of Ethanol-Methylcellulose based Green Gel Propellant Viscosity at Varying Temperature

2021 ◽  
Vol 23 (07) ◽  
pp. 1293-1302
Author(s):  
Saugata Mandal ◽  
◽  
Balaguru Pandian ◽  
Rajarshi Das ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Power Law ◽  
Empirical Model ◽  
Rheological Behavior ◽  
Empirical Estimation ◽  
Propulsion Systems ◽  
Shear Rates ◽  
Temperature Range ◽  
Shear Thinning Fluids ◽  
Good Agreement

The rheological behavior of the Ethanol based green gels for use in propulsion systems at temperature range of 100C – 500C is investigated by employing a novel empirical model developed. The study is conducted at various shear rates. Empirically predicted results were observed to be in good agreement with experimental data at higher shear rates for both pure and energized gel system (>100 s-1). Considering the results, the present empirical model is deemed suitable for those Non Newtonian shear thinning fluids which obey Power law.

scholarly journals A hierarchical cellular structural model to unravel the universal power-law rheological behavior of living cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiu-Tao Hang ◽  
Yu Kang ◽  
Guang-Kui Xu ◽  
Huajian Gao
Keyword(s):  
Power Law ◽  
Rheological Behavior ◽  
Structural Model ◽  
Complex Modulus ◽  
Structural Characteristics ◽  
Living Cells ◽  
Mechanical Responses ◽  
Universal Power Law ◽  
Power Law Exponent ◽  
Self Similar

AbstractLiving cells are a complex soft material with fascinating mechanical properties. A striking feature is that, regardless of their types or states, cells exhibit a universal power-law rheological behavior which to this date still has not been captured by a single theoretical model. Here, we propose a cellular structural model that accounts for the essential mechanical responses of cell membrane, cytoplasm and cytoskeleton. We demonstrate that this model can naturally reproduce the universal power-law characteristics of cell rheology, as well as how its power-law exponent is related to cellular stiffness. More importantly, the power-law exponent can be quantitatively tuned in the range of 0.1 ~ 0.5, as found in most types of cells, by varying the stiffness or architecture of the cytoskeleton. Based on the structural characteristics, we further develop a self-similar hierarchical model that can spontaneously capture the power-law characteristics of creep compliance over time and complex modulus over frequency. The present model suggests that mechanical responses of cells may depend primarily on their generic architectural mechanism, rather than specific molecular properties.

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