Tube flow behavior and shear stress-shear rate characteristics of canine blood

1962 ◽  
Vol 203 (3) ◽  
pp. 417-421 ◽  
Author(s):  
S. Charm ◽  
G. S. Kurland
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
High Speed ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Tube Flow ◽  
Marginal Gap ◽  
Rate Information ◽  
Power Law Equation ◽  
Gap Width

The shear stress-shear rate characteristics of canine blood were determined in a cone and plate viscometer and could be expressed by a power-law equation. The differences in the shear stress-shear rate and tube flow characteristics suggest a marginal gap of plasma at the tube wall. It also appears from these considerations that the gap width of plasma increases with tube diameter. Laminar flow considerations are insufficient for explaining tube flow behavior. High-speed motion pictures indicate collisions between cells in tube flow and the cells do not appear to remain in discrete streamlines. It is suggested that these uncalculated energy losses are the reason why tube flow behavior cannot be predicted from shear stress-shear rate information.

Application of R/S Rheometer in Low Temperature Drilling Fluid Rheology Determination

2012 ◽  
Vol 490-495 ◽  
pp. 3114-3118
Author(s):  
Xiao Ling Jiang ◽  
Zong Ming Lei ◽  
Kai Wei
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Low Temperature ◽  
High Speed ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Rheological Parameter ◽  
Fluid Temperature ◽  
Fluid Rheology ◽  
Rotary Viscometer

With six-speed rotary viscometer measuring the rheology of drilling fluid at low temperature, during the high-speed process, the drilling fluid temperature is not constant at low temperature, which leads to the inaccuracy in rheological measurement. When R/S rheometer is used cooperating with constant low-temperature box , the temperature remains stable during the process of determining the drilling fluid rheology under low temperature. The R/S rheometer and the six-speed rotational viscometer are both coaxial rotational viscometers, but they work in different ways and the two cylindrical clearance between them are different.How to make two viscometer determination result can maintain consistent?The experimental results show that, The use of R/S rheometer, with the shear rate for 900s-1 shear stress values instead of six speed rotary viscometer shear rate for 1022s-1 shear stress values.Then use two-point formula to calculate rheological parameters.The R/S rheometer rheological parameter variation with temperature has a good linear relationship,Can better reflect the rheological properties of drilling fluids with low temperature changerule

Shaping Air Flow Characteristics of a High-Speed Rotary-Bell Sprayer for Automotive Painting Processes

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Ch. Stevenin ◽  
Y. Béreaux ◽  
J.-Y. Charmeau ◽  
J. Balcaen
Keyword(s):  
High Speed ◽  
Vortex Breakdown ◽  
Flow Behavior ◽  
Air Flow ◽  
Flow Characteristics ◽  
Rotation Frequency ◽  
Zone Length ◽  
Swirling Jets ◽  
Automotive Parts

Electrostatic rotary bell sprayers (ERBS) are widely used in automotive painting applications. These processes involve complex airflows to shape paint sprays and transport droplets toward automotive parts to be coated. Despite the importance of shaping airflow on global spray characteristics, a detailed characterization of this aerodynamic flow is still missing. For this purpose, an experimental study was conducted on the influence of some ERBS operating parameters on the development and characteristics of shaping airflow. Results show that, for low swirl numbers, the flow behavior is close to that of annular swirling jets and a good agreement is found between ERBS flow characteristics and data available in literature. When rotational speed of the bell cup is sufficiently fast, a change of regime is observed with a shift in the longitudinal flow development and an increase of recirculation zone length. This change of regime is attributed to vortex breakdown instability, known to occur when high swirl strength is beyond a critical value. Experimental results obtained in this study put forward a clear link between the shaping air flow rate and the rotation frequency on the aerodynamics and also provide valuable leads to design shaping air flow in modern ERBS.

The Effects of Particle Segregation on Debris Flow Fluidity Over a Rigid Bed

2020 ◽  
Vol 27 (1) ◽  
pp. 139-149
Author(s):  
Norifumi Hotta ◽  
Tomoyuki Iwata ◽  
Takuro Suzuki ◽  
Yuichi Sakai
Keyword(s):  
Shear Stress ◽  
Debris Flow ◽  
Debris Flows ◽  
High Speed ◽  
Particle Diameter ◽  
Flow Characteristics ◽  
Video Camera ◽  
Front Velocity ◽  
Flow Depth ◽  
Particle Segregation

ABSTRACT It is essential to consider the fluidity of a debris flow front when calculating its impact. Here we flume-tested mono-granular and bi-granular debris flows and compared the results to those of numerical simulations. We used sand particles with diameters of 0.29 and 0.14 cm at two mixing ratios of 1:1 and 3:7. Particle segregation was recorded with a high-speed video camera. We evaluated the fronts of debris flows at 0.5-second intervals. Then we numerically simulated one-dimensional debris flows under the same conditions and used the mean particle diameter when simulating mixed-diameter flows. For the mono-granular debris flows, the experimental and simulated results showed good agreement in terms of flow depth, front velocity, and flux. However, for the bi-granular debris flows, the simulated flow depth was less, and both the front velocity and flux were greater than those found experimentally. These differences may be attributable to the fact that the dominant shear stress was caused by the concentration of smaller sediment particles in the lower flow layers; such inverse gradations were detected in the debris flow bodies. Under these conditions, most shear stress is supported by smaller particles in the lower layers; the debris flow characteristics become similar to those of mono-granular flows, in contrast to the numerical simulation, which incorporated particle segregation with gradually decreasing mean diameter from the front to the flow body. Consequently, the calculated front velocities were underestimated; particle segregation at the front of the bi-granular debris flows did not affect fluidity either initially or over time.

Physical and Rheological Properties of Animal Manure: A Review

2018 ◽  
Vol 61 (3) ◽  
pp. 1113-1120
Author(s):  
Ibrahim Denka Kariyama ◽  
Xiaodong Zhai ◽  
Binxin Wu
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Power Law ◽  
Apparent Viscosity ◽  
Flow Behavior ◽  
Pressure Head ◽  
Animal Manure ◽  
Anaerobic Treatment ◽  
Pseudoplastic Fluid ◽  
Power Law Equation

Abstract. This literature review was conducted on the physical and rheological properties of animal manure slurries and their applications. The review revealed the importance of these properties in the design of anaerobic treatment plants, pipe systems to transport slurries to treatment and storage units, and other applications and management of raw and treated slurries. The selection of pumping and mixing equipment and their power requirements, the flow behavior, mass, and heat transfer, the quality of mixing, pressure head loss, and other applications of manure slurries are affected by the physical and rheological properties. The review shows that manure slurries generally exhibit non-Newtonian pseudoplastic fluid behavior with a decreasing apparent viscosity as the shear rate increases and that the power law equation can successfully be used to describe the relationship between shear stress and shear rate, especially for low total solids concentrations. Keywords: Animal manure slurries, Apparent viscosity, Non-Newtonian pseudoplastic fluids, Power law equation, Rheological properties.

scholarly journals Aqueous Solutions of Polyethoxylated Fatty Alcohols Rheological behavior and superficial properties

2019 ◽  
Vol 70 (2) ◽  
pp. 382-386
Author(s):  
Andra Tamas ◽  
Sabina Nitu
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Aqueous Solutions ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Fatty Alcohols ◽  
Flow Behavior Index ◽  
Foaming Power ◽  
Newtonian Behavior ◽  
Behavior Index

The paper presents the study of the rheological and superficial behavior (foaming power and wetting capacity) of some aqueous solutions with polyethoxylated fatty alcohols content. The influence of fatty alcohols concentration and their degree of ethoxylation as well as that of temperature on the rheological behavior was determined from the dependences between the shear stress t and the shear rate. The results demonstrate that all the studied solutions have non-Newtonian behavior, with flow behavior index smaller than 1.

Viscoelastic Behavior of Disperse Systems with Silicone Oil and Different Fillers

2002 ◽  
Vol 12 (6) ◽  
pp. 297-302 ◽  
Author(s):  
Dimiter Hadjistamov
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Normal Stress ◽  
Silicone Oil ◽  
Flow Behavior ◽  
Normal Stress Difference ◽  
Filler Concentration ◽  
Stress Difference ◽  
Disperse Systems ◽  
First Normal Stress Difference

Abstract The rheological behavior of model suspensions with the silicone oil M20000 and different concentrations of Cab-o-sil TS 720 resp. Durcal 5 are compared. The increase of the Cab-o-sil concentration changes the flow behavior of the suspension from shear-thinning, to pseudoplastic, and to plastic flow behavior. The first normal stress difference rises at the same time at certain shear rate. The disperse systems with Durcal 5 keep the structural viscous behavior of the silicone oil even with a filler concentration of 40.5 wt%. The dependence of the first normal stress difference on shear rate represents for suspensions with Durcal 5 only one straight line with a slope of n = 2. The normal stress has double the amount of the silicone oil M20000 at given shear rate and is independent of the used Durcal 5 concentration. It was established that suspensions with the silicone oil M20000 have a first normal stress difference that can, depending on the filler type, either increase (with Cab-o-sil TS 720) or decrease (with Durcal 5) at certain shear stress with increasing filler concentration. It is to be supposed that the decrease of the normal stress at a given shear stress, with increasing Durcal concentration, is a softening effect, caused by the filler.

scholarly journals Effect of Octyl Salicylate With Respect To the Physical Appearance of Mono/Di Caprylic and Capric Fatty Acids Formulations

2016 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Fatty Acids ◽  
Particle Size ◽  
Shear Stress ◽  
Shear Rate ◽  
Flow Behavior ◽  
Physical Appearance ◽  
Newtonian Fluids ◽  
Particle Sizes ◽  
Medium Chain ◽  
Medium Chain Fatty Acids

Caprylic and capric acids are classified as medium-chain fatty acids. In this study, the behavior of the caprylic and capric acids formulations containing octyl salicylate were investigated. The formulations were prepared using homogenization proses. The characteristics of the formulation such as particle size, flow behavior, microscopic view and absorbance of the formulations were investigated. Particle sizes of the formulations were found ranging from 352.7 - 704.2 nm. The viscosity of the formulations changed as the shear rate was varied and could be classified as non-Newtonian fluids. The viscosity decreases when the fluid undergoes longer shear stress with time. The formulations containing octyl salicylate shows higher absorbance as compared to the formulations without octyl salicylate. The addition of octyl salicylate affected the system in terms of behavior, appearance and stability

The flow characteristics of halloysite suspensions

Clay Minerals ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 99-106 ◽  
Author(s):  
B. K. G. Theng ◽  
N. Wells
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Particle Shape ◽  
Flow Characteristics ◽  
Linear Increase ◽  
Point Of Zero Charge ◽  
Particle Interactions ◽  
Yield Value ◽  
Edge Surface ◽  
Rotary Viscometer

AbstractThe rheology of aqueous suspensions of Na halloysites with different particle shape has been investigated using a Haake rotary viscometer. Three halloysites from New Zealand were used: Matauri Bay (MB), Te Akatea (TA) and Opotiki (Op) which are mainly composed of thick long tubules, short thin laths, and spherules, respectively. Suspensions of the materials subsequently prepared from the MB and TA samples show a pseudoplastic consistency under shear, characterized by a steep initial rise in shear stress as shear rate increases, followed by a linear increase in stress when a certain shear rate is exceeded. The Op halloysite, on the other hand, shows Newtonian flow behaviour for which shear stress increases linearly with shear rate throughout. For MB and TA, the shear stress developed during rotor acceleration is larger than that produced during deceleration, and the corresponding flow curves enclose a hysteresis loop. As suspension pH increases, the pseudoplastic character decreases as does the amount of hysteresis. Above pH 7.5, flow approaches Newtonian and hysteresis is absent. Plots of Bingham yield value against pH at different ionic strengths (0.003, 0.03 and 0.3 M NaCl) intersect at pH 6.0 for MB and at pH 7.1 for TA. These values are identified with the point of zero charge (PZC) of the particle edge surface. The flow characteristics of halloysites may be explained in terms of the influence of particle shape, pH, electrolyte concentrations, and layer composition on particle interactions.

Study on Turbulent Behavior of Water Jet in Supersonic Steam Injector

2008 ◽  
Author(s):  
Akira Fukuichi ◽  
Yutaka Abe ◽  
Akiko Fujiwara ◽  
Yujiro Kawamoto ◽  
Chikako Iwaki ◽  
...  
Keyword(s):  
Shear Stress ◽  
Turbulent Flow ◽  
Momentum Transfer ◽  
Total Pressure ◽  
Direct Contact ◽  
High Speed ◽  
Flow Behavior ◽  
Water Jet ◽  
High Efficient ◽  
Contact Condensation

One of the most interesting devices for Next-generation nuclear reactor systems aimed at simplified system, improvement of safety and credibility is a supersonic steam injector. Supersonic steam injector is a passive jet pump without rotating machine and high efficient heat exchanger because of the direct contact condensation between the supersonic steam and the subcooled water jet. It is considered that flow behavior in the supersonic steam injector is governed by the complicated turbulent flow with large shear stress induced by velocity difference between the steam and water and direct contact condensation. There are various studies about formulation of operating characteristic of the steam injector and jet structure in it [1][5]. According to these investigations, heat and momentum transfer of the steam injector are supposed to be related to the turbulent eddy diffusion. However, the studies about the turbulent flow under the large shear stress with direct contact condensation are not enough. Especially mechanisms of the momentum and the heat transfer are not clarified in detail. Objective of the present study is to investigate the turbulent behaviors of the water jet and the interface between the water and the supersonic steam that play an important role in the heat and the momentum transfer. Radial velocity distribution was measured by a special pitot tube. Fluctuation of the total pressure which doesn’t depnd on the density of the fluid is measured by the pitot measurement. It was found that the streamwise velocity increased as it approaches downstream of the injector. Fluctuation of the total pressure is large at the mixing region of the water and the steam. Visual measurement of the turbulent water jet was conducted by high speed camera in order to identify the position of unstable interface and its behavior. It was confirmed that wave propagated on the interface. And its velocity is obtained.

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