1. Examples : water. All liquids and gases are fluids.
2. Pressure is defined as the physical force exerted on an object. The force applied is perpendicular to the surface of objects per unit area. The basic formula for pressure is F/A (Force per unit area). Unit of pressure is Pascals (Pa). Types of Pressures are Absolute, Atmospheric, Differential, and Gauge Pressure..
3. Density
3.1. Definition: Density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre
3.2. Example : The density of water is 1 g/cm3
4. Pressure
4.1. Example : While you are sipping beverages from a straw, you actually suck the air out of the straw. Because While you sip the beverage, you’re actually applying ‘Pressure’.
5. Fluid :
5.1. A fluid is any substance that flows or deforms under applied shear stress.
6. Reynolds Number can therefore be expressed as Re = ρ u L / μ = ρ u2 / (μ u / L) = u L / ν (1) where Re = Reynolds Number (non-dimensional) ρ = density (kg/m3, lbm/ft3) u = velocity based on the actual cross section area of the duct or pipe (m/s, ft/s) μ = dynamic viscosity (Ns/m2, lbm/s ft) L = characteristic length (m, ft)
7. Equations to calculate this phenomena’s
7.1. Continuity equation
7.1.1. Q=A1V1= A2V2
7.1.2. Where V= velocity , A=area of flow and Q= volumetric flow rate.
7.1.3. for a fluid passing through a tube in a steady flow, the mass flowing through any section of the tube in a unit of time is constant.
7.2. Bernoulli’s equation
7.2.1. p+1/2p(rho)V2ª+pgh
7.2.2. Where: p is pressure, rho is density, V is velocity , g is gravity and h is height.
7.2.3. points 1 and 2 lie on a streamline, the fluid has constant density, the flow is steady, and there is no friction.
7.3. Torricelli’s equation
7.3.1. V= (square root ) of 2gh
7.3.1.1. Where: V= speed at which the liquid comes out of the tank G= gravitational acceleration H= height from the hole to the water’s surface The speed at which the liquid will flow out of the water tank will be the same as an object free falling from the same height.
7.3.2. Reynolds number (Rn) is defined as Rn=(ρVL)/μ=(VL)/ν, where V is the fluid velocity relative to the body and L is a typical length.
7.3.3. calculate the speed at which a liquid will be moving, if there is no change in pressure and only the gravity acts on it. A good example of it is a hole on the wall of an open water tank.