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Showing posts with the label 22January 2021

Fluid Mechanics

  Gauge Pressure and Absolute Pressure: Gauge Pressure: It is convenient to measure pressure in terms of taking atmospheric pressure as reference datum.  Pressure measured above atmospheric pressure is known as gauge pressure.  The atmospheric pressure on the scale is marked as zero. Absolute Pressure: Since, atmospheric pressure changes with atmospheric condition, a perfect vacuum is taken as an absolute standard of pressure.  Pressure measured above perfect vacuum are called absolute pressure. The figure  explains the concept of gauge and absolute pressure.  Absolute pressure = atmospheric pressure + gauge pressure P abs  =  P atm  +  P gauge                                   Fig. 1 Concept of gauge and absolute pressure Pascal's Law: It states that the intensity of pressure at any point in a liquid at rest is same in all direction. We consider a fluid...

Fluid Mechanic's

  STATIC PRESSURE OF LIQUIDS , HYDRAULIC PRESSURE, ABSOLUTE AND GAUGE PRESSURE  Introduction Fluid has property that it exerts force on all the sides, top and bottom. Pressure exerted by fluid is given as force per unit area which is as follows:          Pressure= Force Applied / Area Exposed SI unit of pressure is   newton   per square metre (N/m 2 ). This is also known as   pascal   (Pa).  The values of standard atmospheric pressure are as follows:    760 mm of mercury column  10.3 m of water column  101.3 kN/m2  101.3  kPa   1 bar Hydrostatic Law: Pressure in a continuously distributed uniform static fluid varies only with vertical distance and is independent of the shape of the container. The pressure is the same at all points on a given horizontal plane in the fluid.  The pressure increases with depth in the fluid. Pressure head of liquid: Consider a fluid of density ρ, having f...