Tiêu đề 1.6 Fluid Pressure.pdf ✅

Fluid Pressure at point • Consider a small area dA in large mass of fluid. If the fluid is stationary, then the force exerted by the surrounding fluid on the area dA will always be perpendicular to the surface dA. • Let dF is the force dF is acting on the area dA in the normal direction. Then the ratio of is known as the intensity of pressure or simply pressure and this ratio is represented by p. • Hence mathematically the pressure at a point in a fluid at rest is p = (dF)/(dA) • If the force (F) is uniformly distributed over the area (A), then pressure at any point is given by p = F/A = (Force)/(Area) • Force or pressure force, F = p x A Units (i) kgf / m2 and kgf/cm2 in MKS units, (ii) Newton/m2 or N / m2 and N / mm2 N / m2 is known as Pascal and is represented by Pa. Other commonly used units of pressure are kPa = kilo pascal = 1000 N/m2 1 bar = 100 kPa = 105N/m2.

Pressure variation in a fluid at Rest