
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

Fluid mechanics uinit 1

4 pages, 0 questions, 0 questions with responses, 0 total responses,

	sonysundar	+Fave Message
	Profile Timeline Uploads

Home > sonysundar >

Formatting page ...

UNIT 1 FLUID A fluid is a substance which offers no resistance to shear deformation and will continue to deform when subjected to shear stresses. FLUID MECHANICS: Fluid mechanics is that branch of science that deals with the behaviour of the fluids at rest as well as in motion. Thus this branch of science deals with the static, kinematics and dynamic aspects of fluids. The study of fluids at rest is called fluid statics. The study of fluids in motion, where pressure forces are not considered is called fluid kinematics and if the pressure forces are also considered for the fluids in motion that branch of science is called fluid dynamics. PROPERTIES OF FLUID: 1. Density or Mass Density Density or mass density of a fluid is defined as the ratio of the mass a fl uid to its volume. It is denoted in symbol (rho). The value of density of water is 1000 kg/m3. = Mass of fluid / volume of fluid 2. Specific weight or Weight density ( ) Specific weight or Weight density of a fluid is the ratio between the weight of a fluid to its volume. The value of specific weight or weight density of water is 9810 N/m3. Weight of fluid = Mass of fluid * Acceleration due to gravity Specific weight or Weight density ( ) = g = weight/volume 3. Specific volume Specific volume of a fluid is defined a s the volume of a fluid occupied by a unit mass or volume per unit mass of a fluid. Specific volume = Volume of fluid / mass of fluid = 1/ Specific volume is the reciprocal of mass density. It is expressed as m3/ kg. It is commonly applied to gases. 4. Specific gravity or Relative density (G) Specific gravity is defined as the ratio of weight density (or density) of a fluid to the weight density (or density) of a standard fluid. G = liquid / water G = liquid / water 5. Viscosity: Viscosity is defined as the property of a fluid which offers resistance to the movement of one layer of fluid over another adjacent layer of the fluid. = du/dy = shear stress = dynamic viscosity du = velocity dy = distance Viscosity is also defined as the shear stress required to produce unit area of strain. Unit of dynamic viscosity ( ) is Ns/m2. 10 Poise = 1 Ns/m2. Newton s law of viscosity states that the shear stress ( ) on a fluid element layer is directly proportional to the rate of shear strain. The constant of proportionality is called the coefficient of viscosity ( ). Fluids which obey the above relation are known as Newtonian fluids and the fluids which do not obey above relation is known as Non-Newtonian fluids. Kinematic viscosity: It is defined as the ratio between the dynamic viscosity and density of fluid. It is denoted by (nu) and its unit is m2/s. = / 1 Stoke = 1 m2/s = 1 10-4 cm2/s 6. Surface tension Surface tension ( ) is defined as the tensile force acting on the surface of a liquid in contact with a gas or on the surface between two immiscible liquids such that the contact surface behaves like a membrane under tension. Unit is N/m. Surface tension on liquid droplet P = 4 /d Surface tension on hollow bubble P = 8 /d Surface tension on a liquid jet P = 2 /d 7. Capillarity Capillarity is defined as a phenomenon of rise or fall of a liquid surface in a small tube relative to the adjacent general level of liquid when the tube is held vertically in the liquid. The rise of liquid surface is known as capillarity rise while the fall of the liquid surface is known as capillarity depression. Unit is m or mm. Rise of water, h = 4 / ( g d) Capillary fall, h = 4 cos / ( g d)

Formatting page ...

sonysundar chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: