Introduction to Fluid Mechanics

With increase in temperature, viscosity of liquids

1. Increases
2. Decreases
3. Remains same
4. Becomes zero

Newton's law of viscosity relates

1. Pressure & velocity
2. Shear stress & velocity gradient
3. Density & temperature
4. Force & area

Pascal's law states that pressure applied to fluid is

1. Lost
2. Reduced
3. Transmitted equally
4. Increased

Steady flow means

1. Velocity changes with time
2. Velocity remains constant with time
3. Pressure changes
4. Density changes

Laminar flow occurs at

1. High Reynolds number
2. Low Reynolds number
3. Zero velocity
4. High pressure

Ideal fluid has

1. High viscosity
2. Zero viscosity
3. High density
4. Variable pressure

Continuity equation represents

1. Energy conservation
2. Mass conservation
3. Momentum conservation
4. Pressure variation

Euler's equation is based on

1. Energy conservation
2. Momentum conservation
3. Mass conservation
4. Heat transfer

Mach number is ratio of

1. Velocity to sound speed
2. Pressure to density
3. Force to area
4. Density to viscosity

Hagen-Poiseuille law is valid for

1. Turbulent flow
2. Laminar flow
3. Compressible flow
4. Ideal flow

Define the following : (i) Mass density (ii) Specific Gravity (iii) Dynamic Viscosity (iv) Capillarity (v) Vapour Pressure.

The dynamic viscosity of oil used for lubrication between a shaft and sleeve is 8 poise. The shaft is of diameter 0.4 m and rotates at 190 rpm. Calculate the power lost in the bearing for a sleeve length of 90mm. The thickness of the oil film is 1.5mm.

What is manometer? Distinguish between U-tube differential manometer and inverted U-tube differential manometers.

Explain the procedure of finding hydrostatic force on curved surface.

Distinguish between (i) Study and Unsteady flow (ii) Uniform and non-uniform flow (iii) compressible and incompressible.

If for a two-dimensional potential flow, the velocity potential is given by Ø = x(2y - 1). Determine the velocity at the point P (4, 5). Also determine the value of stream function Ψ at the point P.

Define the following terms: Velocity potential function, stream function, equipotential line and flow net.

The water is flowing through a pipe having diameters 20cm and 10cm at section 1 and 2 respectively. The rate of flow through pipe is 35 litres/sec. The section 1 is 6m above datum and section 2 is 4m above datum. If the pressure at section 1 is 39.24N/cm². Find the intensity of pressure at section 2.

Drive an expression for head loss due to sudden enlargement in a pipe flow.

Prove that the maximum velocity in a circular pipe for viscous flow is equal to two times the average velocity of flow.

At a sudden enlargement of a water main from 240 mm to 480 mm diameter, the hydraulic gradient raises by 10mm. Estimate the rate of flow.

The rate of flow of water through a horizontal pipe is 0.25m³/s. The diameter of the pipe which is 200 mm is suddenly enlarged to 400 mm. The pressure intensity in the smaller pipe is 11.772 N/cm². Determine: (i) Loss of head due to sudden enlargement (ii) Pressure intensity in the large pipe (iii) Power loss due to enlargement.

Explain the different type of hydraulic similarity that must exists between a prototype and its model.

Drive on the basis of dimensional analysis suitable parameter to present the thrust development by a propeller. Assume that the thrust P depends upon the angular velocity ω, speed of advance V, diameter D, dynamic viscosity μ, mass density ρ, elasticity of the fluid medium which can be denoted by the speed of sound in the medium of C.

Define the term velocity potential function, stream function, and establish relation between them

State Buckingham's π theorem

Obtain an expression for continuity equation for three dimensional flow

What is capillary? Obtain an expression for capillary rise of a liquid in a glass tube