Fluid Mechanics & Hydraulics — Summer 2020

Define density, specific volume & surface tension.

The velocity distribution for flow over a flat plate is given by u = 0.75 y - y2 in which u is the velocity in metre per second at a distance y metre above the plate. Determine the shear stress at y = 0.20 m. Take dynamic viscosity of fluid as 8.0 poise.

Eux=p3l/a4i n the phenomenon of capillarity.Obtain an expression for capillary rise of a liquid.

Define atmospheric, absolute & vaccum pressure.

Explain hydrostatic paradox.

Write short note on manometers.

State & prove Pascal’s law.

Define total pressure, centre of pressure & buoyancy.

Arectangular plane surface is immersed vertically in water such that its upper edge is touching free surface of liquid. Show that the depth of centre of pressure is 2/3 d for rectangular surface of width b and depth d.

Define metacentre & metacentric height. How will you determine metacentric height of a floating body experimentally? Explain with neat sketch.

Define stream lines, streak lines & flow net.

Differentiate between (i) Uniform & non uniform flow (ii) Sub critical & super critical flow.

State & prove Bernoulli’s equation & write assumption made for such a derivation.

Define orifice, mouthpiiece & notches.

Find the discharge of water flowing over a rectangular notch of 2.0 m length when the constant head over the notch is 500 mm.Take C d = 0.62

Differrentiate between small & large orifice.Obtain an expression for discharge through large orifice.

Define major energy losses in pipe, hydraulic gradient line & total energy line.

Three pipes of lengths 800 m, 500 m and 400 m and of diameters 500 mm, 400 mm & 300 mm respectively are connected in series. These pipes are to be replaced by a single pipe of length 1700 m. Find the diameter of the single pipe.

Define viscous flow. Derive expression for Hagen-Poiseuille’s formula.1

Define turbulent flow in open channel, specific energy curve & hydraulic jump.

Asluice get discharges water into a horizontal rectangular channel with a velocity of 10 m/sec & depth of flow of 1 m.Determine the depth of flow after the jump & consequent losses in total head.

Define gradually varied flow. Derive equation of gradually varied flow.

Define dimensional homogeneity, similitude & undistorted models

Explain method of selecting repeating variables.

The pressure difference Δp in a pipe of diameter Dand length l due to viscous flow depends on the velocity V, viscosity μ & density ρ. Using Buckingham’s π theorem obtain an expression for Δp.2