Kinematic viscosity is a measure of a fluid’s internal resistance to flow under gravitational forces . It is determined by measuring the time in seconds, required for a fixed volume of fluid to flow a known distance by gravity through a capillary within a calibrated viscometer at a closely controlled temperature.
What is kinematic viscosity and its significance?
One way is to measure a fluid’s resistance to flow when an external force is applied . This is dynamic viscosity. ... The result is kinematic viscosity. Put another way, kinematic viscosity is the measure of a fluid’s inherent resistance to flow when no external force, except gravity, is acting on it.
Why do we need kinematic viscosity?
Kinematic viscosity is an important property of fuel , which directly influences the fuel atomization quality and size of the fuel droplet in the spray. In general, kinematic viscosity is measured using the ASTM Standard D445 and EN 3104 test methods.
What is the difference between absolute and kinematic viscosity?
The relationship between these two properties is quite straightforward. Dynamic viscosity (also known as absolute viscosity) is the measurement of the fluid’s internal resistance to flow while kinematic viscosity refers to the ratio of dynamic viscosity to density .
What is the value of kinematic viscosity?
The kinematic viscosity is an atmospheric variable defined as the ratio between the dynamic viscosity μ and the density ρ of the fluid, i.e. and depends on both air temperature and pressure. For air at sea level pressure and 20 °C, ρ = 1.205 × 10 − 3 g cm − 3 and ν = 0.15 cm 2 s − 1 .
What is the SI unit of viscosity?
Dynamic viscosity: The SI physical unit of dynamic viscosity (μ) is the Pascal-second (Pa s) , which is identical to 1 kg m − 1 s − 1 . The physical unit for dynamic viscosity in the centimeter gram second system of units (cgs) is the poise (P), named after Jean Poiseuille.
How is viscosity calculated?
There are several formulas and equations to calculate viscosity, the most common of which is Viscosity = (2 x (ball density – liquid density) x g x a^2) ÷ (9 x v) , where g = acceleration due to gravity = 9.8 m/s^2, a = radius of ball bearing, and v = velocity of ball bearing through liquid.
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.
Which of the following is kinematic viscosity?
(2) Kinematic Viscosity: The ratio of dynamic viscosity to density appears frequently and this ratio is given by the name kinematic viscosity. Its unit is Stoke or m2/s (1 stoke = 0.0001 m2 /s). ∴ C.G.S unit of kinematic viscosity is cm 2 /s.
What is the physical significance of viscosity?
Significance of Viscosity: It describes the internal friction of a moving fluid . A fluidwith large viscosity resists motion because its molecular makeup gives it a lot of internal friction. A fluid with low viscosity flows easily because its molecular makeup results in very little friction when it is in motion.
What is kinematic viscosity formula?
The units of kinematic viscosity are established on time and area. It is the ratio of the dynamic viscosity to its density, a force independent quantity. It is the ratio of the area of time; henceforth it is m22/s or ft22/s. The kinematic viscosity formula is expressed as, ν = μ/ρ
What are the factors that affects viscosity?
Viscosity is influenced by the composition of the crude oil, the temperature, dissolved gas content, and the pressure . As temperature increases, the viscosity will decrease. As a result, viscosity measurements are always reported with the temperature at which the measurement is made.
Does temperature affect viscosity?
The liquid viscosity is highly affected by the heat. The viscosity decreases with an increase in temperature .
What is the highest viscosity?
One of the most viscous liquids known is pitch , also known as bitumen, asphalt, or tar. Demonstrating its flow and measuring its viscosity is the subject of the longest continuously running scientific experiment, begun in 1927 at the University of Queensland in Australia.
Where is kinematic viscosity used?
5 Kinematic Viscosity (ASTM D445) Kinematic viscosity of bio-oil is typically measured at 40°C to determine the fluidity property. The viscosity value of bio-oil is used to determine the stability of liquid fuel during storage .
How can viscosity be used in real life?
- 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.
