common Fluids around us

Fluids in Our Daily Life

Submitted to: Sir Dr. Shahid Naveed Sahib Submitted by: Muhammad Usman (08-chem-02-B)

Date: 14 September 2009

Department of Chemical Engineering University of Engineering and Technology, Lahore Fluid: A fluid is a substance that doesn’t permanently resist distortion.

Types of fluids: Fluids are classified with respect to their nature. A common classification of fluids is presented below…

➢ On the basis of change in density 1. Compressible fluids: 2. Incompressible fluids

Incompressible fluids: These are the fluids whose density changes to a little extent with the moderate change in temperature and pressure. Liquids are considered as the common example of incompressible fluids.

Compressible fluids: These are the fluids whose density changes considerably with moderate change in temperature and pressure. Their common example is 1. Gases 2. Air However with the small changes in temperature and pressure gases are also considered as incompressible fluids.

➢ On the basis of their viscosity: On the basis of viscosity liquids are classified into two types which are further subdivided. 1. Newtonian fluids 2. Non Newtonian fluids

Newtonian fluids: Fluids that show their linear line behavior when a graph is plotted with velocity gradient at one axis and the shear stresses at the other. This straight line passes through the origin. In general we can say that in their behavior they are somewhat similar to water.

Non Newtonian fluids: Fluids whose curves show deviations from a straight line when their behavior is plotted on the graph (between velocity gradient at one axis and shear stresses at the other axis) are called Non Newtonian fluids They are further subdivided on the basis of their graphical curved shapes. 1. Bingham plastic: Fluids that do not flow at all until a Threshold shear stress is reached are called Bingham fluids. After this threshold shear stress they follow the linear behavior like that of water.

In general they are the Newtonian fluids with the difference of this that their line does not pass through the origin. Example: Example of this is the “sewage sludge”. 2. Pseudo plastic fluids: Their curve passes through the origin, is concave downward at low shears and becomes nearly linear at high shears. They are also called shear rate thinning fluids. These fluids are thicker than Newtonian fluids. Example: “Rubber latex” is an example of this type. 3. Dilatants: Their curve is concaving upward at low shears and almost linear at high shears. They are also called shear rate thickening fluids. These are thinner fluids than Newtonian fluids. Example: “Quicksand” and “sand filled emulsions” are the common examples.

Fluids 1

Water

2

Mustard oil

3

Hydraulic oil

4

Engine oil

5

Sugar water solution

6

Turpentine oil

7

Kerosene oil

8

Petrol

9

Diesel

1 0

Mobile oil

1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0

Perfumes Spirits Thinner Shampoo Air Household gas Cold drink Fruit juices C N G Gas Hydrochloric acid