Fluid Mech. – II (CE-604 (A)) - Important Questions

Explain separation of boundary layer, including effect of pressure gradient and methods to prevent it.

Derive an expression for velocity distribution in terms of average velocity for rough pipes.

Define and explain the hydraulic gradient line and total energy line (energy gradient line) for fluid flow in pipes

Write short notes on Hardy Cross method and on hydraulic and energy gradient lines.

Write short notes on water hammer, hydraulic gradient line, pipes in series, Magnus effect and draft tube.

Find the displacement thickness, momentum thickness, and energy thickness for the given boundary layer velocity distribution $\frac{u}{U} = \frac{y}{\delta}$.

Determine the difference in water surface elevations between two tanks connected by a horizontal pipe, accounting for all losses.

What is turbulent flow and what factors determine the type of flow in pipes?

Describe Reynolds experiment for determining critical velocity in pipe flow.

What is meant by turbulence and how does it affect flow properties?

Define boundary layer and explain its development along a thin flat smooth plate held parallel to uniform flow with salient features.

Derive Chezy's and Manning's formulae for open channel flow.

Explain the most economical circular channel section for the condition of maximum velocity.

Determine the maximum flow rate in a concrete-lined circular channel of 3.6 m diameter with bed slope 1:700 and C = 50.

Write short notes on the following

Explain the most economical circular channel section for the condition of maximum discharge.

Find the bed slope of a rectangular channel given width, depth, discharge and Chezy's constant.

What is the specific energy curve? Derive the expression for critical depth.

Determine the maximum discharge through a circular channel given diameter, bed slope and Chezy's constant.

Define the most economical section of a channel and give the conditions for the best rectangular section.

Given specific energy in a rectangular channel, find the maximum possible discharge.

Sluice gate discharges water into horizontal rectangular channel with velocity $10 \text{ m/s}$ and depth $1 \text{ m}$: determine sequent depth after hydraulic jump and loss of energy in total head.

Describe the dynamic equation for rapidly varied flow.

Derive an expression for depth of hydraulic jump in terms of the upstream Froude number.

Explain the essential difference between gradually varied flow and rapidly varied flow with sketches.

Prove that the loss of energy in a hydraulic jump equals $(d_2-d_1)^3/4d_1d_2$, where $d_1$ and $d_2$ are conjugate depths.

Write about Magnus effect.

Determine the drag force, lift force, resultant force and power required for a circular plate moving in stationary air.

Explain the drag forces acting on a sphere.

Given kite dimensions, weight, inclination angles, string tension and wind speed, calculate the coefficients of lift and drag.

Calculate the friction drag on a flat plate placed longitudinally in a stream of oil, including boundary layer parameters.

Differentiate between

Calculate the drag force required to hold a circular disc normal to a wind/air stream at rest.

Given airfoil geometry, angle of attack, velocity, air density and lift/drag coefficients, find the weight (lift) and power required to drive it.

Prove that the manometric head of a centrifugal pump can be expressed as $H_{mano} = AN^2 + BNQ + CQ^2$ where $A$, $B$, $C$ are constants.

Calculate magnitude and direction of resultant force on a stationary vane for a jet deflected by a curved plate.

State which turbine requires a draft tube and derive the expression for draft tube efficiency.

Derive the expression for the minimum speed required for starting a centrifugal pump.

Francis turbine numerical to determine wheel speed in r.p.m. and outlet vane angle neglecting draft tube and losses.

Derive the expression for hydraulic efficiency of a Pelton turbine.

Explain the working of a reciprocating pump.

Differentiate between impulse and reaction turbines, and between radial and axial flow turbines.

Derive an expression for the head lost due to friction in suction and delivery pipes.

Calculate power delivered to runner and hydraulic efficiency of a Pelton wheel from bucket speed, discharge, head, deflection angle and velocity coefficient.

Explain reaction turbine briefly with neat sketch diagram.

A laminar flow is taking place in a pipe of diameter of $200\text{ mm}$. The maximum velocity is $1.5\text{ m/s}$. Find the mean velocity and the radius at which this occurs. Also calculate the velocity at $4\text{ cm}$ from the wall of the pipe.

Write short notes on any two of the following :

Enunciate Newton's law of viscosity. Explain importance of viscosity in fluid motion. What is effect of temperature on viscosity of water and that of air?

For laminar flow of an oil having dynamic viscosity $u = 1.766$ Pa.s in a $0.4$m diameter pipe, the velocity distribution is parabolic with a maximum point velocity of $4$ m/s at the center of the pipe. Calculate the shear stresses at the pipe wall and within the fluid $40$ mm from the pipe wall.

Write a note on the historical development of fluid mechanics.

Discuss the concept that "a fluid continues to deform so long it is acted upon by a shear force".

Explain briefly a pilot tube with neat sketch diagram and also discuss its measurement of velocity.

Find the smallest diameter of a manometer tube such that error due to capillary action in the measured gauge pressure of $100$ N/m$^2$ is less than $5$ percent. The manometric liquid is water.

Derive Euler's equation of motion along a stream line and hence derive the Bernoulli's theorem.

A wooden block floats in water with $5$ cm height projecting above the water surface. The block is next launched in glycerin (relative density $= 1.35$) and projects $7.5$ cm above the surface of glycerin. Make calculations for the height of block and its relative density.

State and prove the Pascal's law and give some examples where this principle is applied.

The velocity potential for a two-dimensional flow is, $\phi = x (2y - 1)$ Determine the velocity at the point $P(4, 5)$. Also obtain the value of stream function at this point $P$.