In statics, Lami’s theorem is an equation that relates the magnitudes of three coplanar, concurrent and non-collinear forces, that keeps a body in static equilibrium.Lami’s theorem states that if three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two forces.Consider three forces A, B, C…
The line representing the sum of pressure head (p/w) and potential head or datum head (z) with respect to some reference line is hydraulic gradient line (H.G.L). The line representing the sum of pressure head (p/w), datum head (z) and velocity head with respect to some reference line is known as total energy line (T.G.L)….
The word ‘Hydraulics’ has been derived from a Greek word ‘Hudour’ which means water. The subject ‘Hydraulics’ is that branch of Engineering – science which deals with water at rest or in motion. The subject ‘Fluid Mechanics’ is that branch of Engineering-science which deals with the behaviorof fluid under the conditions of rest and motion.
Hydraulic Coefficients include Coefficient of contraction, Coefficient of velocity, Coefficient of discharge and Coefficient of resistance. The following are the hydraulic coefficients: 1. Coefficient of contraction (Cc). It is defined as the ratio of area of jet at *vena contracta (ac) to the area of orifice (a). The point at which the streamlines first become parallel is called…
During 17th century, Daniel Bernoulli investigated the forces present in a moving fluid, derived an equation and named it as an Bernoulli’s equation. Below image shows one of many forms of Bernoulli’s equation.The Bernoulli equation gives an approximate equation that is valid only in inviscid regions of flow where net viscous forces are negligibly small compared to inertial, gravitational or…
The atmospheric air exerts a normal pressure upon all surfaces with which it is in contact and it is known as atmospheric pressure. It is also known as barometric pressure. The atmospheric pressure at sea level (above absolute zero) is called standard atmospheric pressure and its value is given as follows : = 10.3 m of water = 760 mm…
The equilibrium of floating bodies is of the following three types: 1. Stable equilibrium. If a body floating in a liquid returns back to its original position, when given a small angular displacement, then the body is said to be in stable equilibrium. 2. Unstable equilibrium. If a body floating in a liquid does not return back…
The following are the important expressions used in orifices and mouthpieces including discharge through large rectangular orifice, discharge through wholly submerged orifice, and more: (a) Discharge through a large rectangular orifice, where Cd = Coefficient of discharge, b = Breadth of the orifice, H1 = Height of the liquid above the top of the orifice,…
The following are the important expressions used in notches and weirs. (a) Discharge over a rectangular notch or weir, where b = Width of notch or weir, and H = Height of liquid above the sill of the notch. (b) Discharge over a triangular notch or weir, For a right angled V-notch, Theeta = 90°. (c) Discharge…
If an incompressible liquid is continuously flowing through a pipe or a channel (whose cross sectional area may or may not be constant), the quantity of liquid passing per second is the same at all sections. This is known as equation of continuity of a liquid flow. Mathematically, Q1 = Q2 = Q3 = ….. or…