Viscosity is a measure of the resistance of a fluid towards being deformed when under shear stress. Hence, it is also known as shear viscosity. It is caused by the attractive forces between molecules in close contact, and the friction between molecular chains .
What factors affect viscosity?
The two main factors that affect viscosity are temperature and silica content .
What causes viscosity to increase?
Viscosity generally increases as the temperature decreases . The viscosity of a liquid is related to the ease with which the molecules can move with respect to one another. Thus the viscosity of a liquid depends on the: strength of attractive forces between molecules, which depend on their composition, size, and shape.
What causes viscous fluid?
Fluid viscosity η is due to friction within a fluid . Flow is proportional to pressure difference and inversely proportional to resistance: Q=p−2p1R.
What is viscosity and how does it occur?
Viscosity, resistance of a fluid (liquid or gas) to a change in shape, or movement of neighbouring portions relative to one another. Viscosity denotes opposition to flow . The reciprocal of the viscosity is called the fluidity, a measure of the ease of flow. Molasses, for example, has a greater viscosity than water.
Does pH affect viscosity?
An increase in viscosity has been observed by increasing heating time and decreasing the pH . High-viscosity dispersions with pseudoplastic and thixotropic flow behaviors were formed at pH 7.0 and 7.5, whereas weak gels were obtained at pH 6.0 and 6.5.
Does higher temperature mean lower viscosity?
The viscosity decreases with an increase in temperature . Most liquids suffer the exponential relationship (Seeton, 2006) between temperature and viscosity rather than linear form (Fig. 6.1). The more viscous the fluid, the more sensitive it is to the temperature change.
What are the 4 factors that affect viscosity?
- Temperature: The viscosity of liquids decreases by about 2% for each degree rise in temperature.
- Chemical Composition: ADVERTISEMENTS: ...
- Colloid Systems: The viscosity of lyophilic colloid solution is generally relatively high.
- Suspended Material:
What are the types of viscosity?
- Dynamic Viscosity. Dynamic viscosity measures the ratio of the shear stress to the shear rate for a fluid.
- Kinematic Viscosity. Kinematic viscosity measures the ratio of the viscous force to the inertial force on the fluid. ...
- Common Units. ...
- Newtonian Fluids. ...
- Non-Newtonian Fluids.
Does branching increase viscosity?
The smaller coil size of a branched chain will tend to decrease the viscosity , although branches long enough to entangle produce a broadened terminal zone and larger viscosity.
What is viscous effect?
Viscous flows occur when the effects of fluid viscosity are balanced by those arising from fluid inertia, body forces , and/or pressure gradients. In such flows, scaling analyses do not allow a priori neglect of any terms in the equations of fluid motion.
What is viscosity in Reynolds number?
The Reynolds number is the ratio of inertial forces to viscous forces within a fluid which is subjected to relative internal movement due to different fluid velocities. ... Counteracting this effect is the viscosity of the fluid, which tends to inhibit turbulence.
What are 3 characteristics of fluids?
Fluids have common properties that they share, such as compressibility, density, pressure, buoyancy and viscosity . However, just because fluids share similar characteristics doesn’t mean the specifics of those characteristics are the same for each material.
What is viscosity and example?
If I fill the same cup with water, for example, the cup will drain much more quickly. Viscosity is a measure of a fluid’s resistance to flow . It describes the internal friction of a moving fluid. ... Gases also have viscosity, although it is a little harder to notice it in ordinary circumstances.
What is an example of high viscosity?
The resistance to such flow is called the viscosity. Liquids which flow very slowly, like glycerin or honey , have high viscosities. ... Honey, mostly glucose and fructose (see image below) is a good example of a liquid which owes its viscosity to hydrogen bonding.
How we can use viscosity in our lives?
- Lubrication in vehicles. When you put oil into your car or truck, you should be aware of its viscosity. ...
- Cooking. Viscosity plays a significant role in the preparation and serving of food. ...
- Manufacturing. Manufacturing equipment requires appropriate lubrication to run smoothly. ...
- Medicine.
