China
Africa
Explore chapters and articles related to this topic
Fluid Flow
Published in C. Anandharamakrishnan, S. Padma Ishwarya, Essentials and Applications of Food Engineering, 2019
C. Anandharamakrishnan, S. Padma Ishwarya
In the case of shear-thickening fluids, apparent viscosity increases with an increase in shear rate. On applying shear, the dispersed phase swells or changes in shape or the molecules cross-link with each other and trap the molecules of the dispersed medium, thus, increasing the viscosity. At a low shear rate, the fluid keeps the solid particles in suspension. On increasing the shear rate, the solid particles separate out and increase the overall volume of suspension which increases the resistance to flow and thereby raises the fluid viscosity. On a rheogram, the flow behavior of a dilatant fluid is represented by a line that begins at the origin and moves concave downward. A well-known example of shear-thickening liquid is a 60% suspension of cornstarch in water.
Fluid Mechanics
Published in Jiro Nagatomi, Eno Essien Ebong, Mechanobiology Handbook, 2018
Tiffany Camp, Richard Figliola
Fluids for which the shearing strain rate is not linearly related to the shear stress are referred to as non-Newtonian fluids. Shear thinning fluids are non-Newtonian fluids whose apparent viscosity decreases as the shear rate increases. A common shear thinning fluid is latex paint. Blood also behaves as a shear thinning fluid at low shear rates. In contrast, shear thickening fluids have apparent viscosities that increase as the shearing strain rate increases. Quicksand is the most commonly presented example of this. Figure 2.2 shows how the rate of shearing strain relates to shear stress for different types of fluids.
Applications
Published in Raj P. Chhabra, CRC Handbook of Thermal Engineering Second Edition, 2017
Joshua D. Ramsey, Ken Bell, Ramesh K. Shah, Bengt Sundén, Zan Wu, Clement Kleinstreuer, Zelin Xu, D. Ian Wilson, Graham T. Polley, John A. Pearce, Kenneth R. Diller, Jonathan W. Valvano, David W. Yarbrough, Moncef Krarti, John Zhai, Jan Kośny, Christian K. Bach, Ian H. Bell, Craig R. Bradshaw, Eckhard A. Groll, Abhinav Krishna, Orkan Kurtulus, Margaret M. Mathison, Bryce Shaffer, Bin Yang, Xinye Zhang, Davide Ziviani, Robert F. Boehm, Anthony F. Mills, Santanu Bandyopadhyay, Shankar Narasimhan, Donald L. Fenton, Raj M. Manglik, Sameer Khandekar, Mario F. Trujillo, Rolf D. Reitz, Milind A. Jog, Prabhat Kumar, K.P. Sandeep, Sanjiv Sinha, Krishna Valavala, Jun Ma, Pradeep Lall, Harold R. Jacobs, Mangesh Chaudhari, Amit Agrawal, Robert J. Moffat, Tadhg O’Donovan, Jungho Kim, S.A. Sherif, Alan T. McDonald, Arturo Pacheco-Vega, Gerardo Diaz, Mihir Sen, K.T. Yang, Martine Rueff, Evelyne Mauret, Pawel Wawrzyniak, Ireneusz Zbicinski, Mariia Sobulska, P.S. Ghoshdastidar, Naveen Tiwari, Rajappa Tadepalli, Raj Ganesh S. Pala, Desh Bandhu Singh, G. N. Tiwari
Two important types of time-independent non-Newtonian fluids are shear thinning (pseudoplastic) and shear thickening (dilatant). The difference between these two can be understood on the basis of apparent viscosity. An apparent viscosity is calculated by assuming that the non-Newtonian fluid obeys Newton’s law of viscosity at a selected shear rate. The slope of the straight line from the origin to a point on the curve at a given shear rate gives the value of apparent viscosity. For a shear thinning fluid, the apparent viscosity decreases as the shear rate increases. Some examples of shear thinning fluids are condensed milk, fruit purees, mayonnaise, mustard, and vegetable soups. For a shear thickening fluid, the apparent viscosity increases as the shear rate increases. Some examples of shear thickening fluids are 40% raw corn starch and some types of honey.
Research on rheology performance and sealing effect of alkali-activated GGBS paste used for tunnel leakage plugging
Published in Journal of Sustainable Cement-Based Materials, 2023
Ping Li, Shiwei Liu, Yin Bai, Jianhui Tang, Jun Tao
Apparent viscosity is an important physical concept and is defined as the ratio of shear stress over shear rate. Figure 9 shows the temporal variation in apparent viscosity of AAS paste at an activator concentration of 3 mol/L and a temperature of 20 °C. Clearly, the time plot of viscosity is similar to that of yield stress curve in Figure 7. The variation in apparent viscosity can be divided into four stages, namely initial rising stage, descending stage, slow rising stage, and rapid rising stage. In the first 1 min (i.e. initial rising stage), the apparent viscosity exhibited an immediate increase when the rheometer rotor began to rotate and broke the early-age structure of the AAS paste. The apparent viscosity gradually decreased between 1 and 10 min (i.e. descending stage). As a build-in low shear mode of the rotor was applied, the breakage of early-age flocs was slow. In addition, the formation of new reaction products took time. Thus, the viscosity gradually fell below the peak apparent viscosity of the initial rising stage. The slow rising stage between 10 and 29 min witnessed a gradual increase in viscosity. This can be explained by the fact that newly formed hydration products exceeded the floc breakage caused by the rotor, thus enhancing the slag particles and accelerating the growth of apparent viscosity. The end of the slow rising stage was defined at the time when the viscosity reached two-fold of the minimum at the third stage. After 39 min (i.e. rapid rising stage), the viscosity continued to rise at an increasing rate.
The Pressure and Temperature Dependency of Relative Volume, Low Shear Viscosity, and Non-Newtonian High Shear Viscosity in SAE AS5780 HPC, MIL-PRF-23699 HTS, and DOD-PRF-85734 Lubricants
Published in Tribology Transactions, 2022
A shear rate is applied through the rotor, resulting in torque applied to the stator that is converted to shear stress. The torque applied is a result of shear between the rotor and stator. The viscosity measurement, often referred to as “apparent viscosity,” is the ratio of the measured shear stress and the applied shear rate. Measurements were made up to 500 MPa and between 5 and 20 °C using an external temperature control system, increasing the viscous power of the viscometer. As a result, a reduction in thermal feedback on the apparent viscosity was achieved. Maximum shear stresses recorded were on the order of 5 MPa. Details of construction and theory can be found in Bair (15).
Interactions between fine particles and heavy crude oil: an experimental study using thermo-gravimetric and rheological analyses
Published in Petroleum Science and Technology, 2022
Mom Vatana, Kyuro Sasaki, Ronald Nguele, Yuichi Sugai
It could be seen that the apparent viscosity increases with increasing shear rate; behaving somewhat like shear-thickening fluid. This is presumably due to the affinity between Si-NP and the heaviest fractions of the crude oil, which further promotes its adsorption (Taborda et al. 2016). Additionally, it could be seen that the larger was Si-NP load, the heavier is the crude oil, which agrees well with the literature (Alade 2021).