Q4. The diameter and stroke of a single-acting reciprocating pump are 300 mm and 500 mm respectively. The pump takes its supply of water from sump 3.2 m below the pump axis through a pipe 9 m long and 200 mm diameter. If separation occurs at (2.4 − ? ??? ) m of water absolute, determine: (i) The speed at which separation may take place at the beginning of suction stroke, and (ii) The speed of the pump if an air vessel is fitted on the suction side 2.4 m above the sump water level. Take atmospheric pressure head = 10.3 m of water, and friction co-efficient, f = 0.01. Where n is the last two digits of student ID number [5.5 Marks

n=6

Explain the recent trends and future of powder metallurgy
technology?

Write the references.

Nitrogen (N2) goes through a constant area pipe (see figure below) at a mass rate of 2 kg/s. It enters the pipe with a velocity of 17 m/s, a pressure of 500 kPa and a temperature of 177 C. It leaves the pipe at the same pressure (500 kPa) and a temperature of 67 C. The molar mass of N2 is 28 kg/kmol. Determine: a) The cross sectional area of the pipe in m2 . b) The velocity at the exit side in m/s. c) The rate of heat transfer in kW between the pipe and the surroundings. Also, indicate its direction.

A steel plate is loaded as shown below with a force F, which fluctuates with the following load pattern for 12 seconds

Load 1: 10 cycles at -3,000 lbf to 3,000 lbf

Load 2: 10 cycles from -2,000 lbf to 8,000 lbf

Load 3: 5 cycles at -8,000 lbf to 8,000 lbf.

Point A is located at the fillet radius. The fillet radii at all points is r = 0.175 in. The fatigue strength fraction is f = 0.80, the fully adjusted endurance limit has been determined to be 30 ksi, the ultimate strength is 160 ksi, and the yield strength is 105 ksi. The notch sensitivity factor q is 0.9. Assume there is no plastic localized strain at point A.

Determine the life of the component at point A in hours if this 12 seconds pattern repeats for the remainder of the part's life.

Explain in two engineering point of view the nittygritties of engineering design in not less than a page.

Final answer only ;

Water (10 C) flows with a speed of (V=1.5 m/s) through a horizontal plastic pipe of diameter (D=0.0622 m). The length of the pipe is (L= 30 m). The friction factor is equal to

a. f = 0.015

b. f = 0.192

c. f = 0.210

d. f = 0.018

The laminar boundary layer occurs

a. Smooth flow

b. Rough flow

c. Uniform flow

d. Random flow

A flow of water passing over a smooth thin flat plate long and wide at a velocity of . Assuming that the boundary layer is laminar at first and then becomes turbulent. Given The distance of the laminar boundary layer downstream of the leading edge is equal to

a. 0.22 m.

b. 0.0022 m

c. 2.22 m

d. None of these

For a rectangular channel of length =10m and its hydraulic radius = 3. The value of the width of the rectangular channel is equal to

a. y = 10

b. y = 4

c. y = 15

d. y = 2

The region of a flow in a pipe where the velocity distribution is variable is called

a. Developing region

b. Laminar flow region

c. Turbulent flow region

d. Developed flow region

What are the reasons for minor head loses in a pipe?

a. Friction

b. Heat

c. Valves and bends

d. Temperature

For a streamlined body to achieve low drag coefficient, the boundary layer must

a. Flow over the body

b. Be attached to the body

c. Move away from the body

d. Move parallel to the body

For a flow between a stationary and moving plates. If the shear stress at the moving plate is 200 N/m2. The shear stress at the center between the plates is

a. Zero.

b. 200 N/m2

c. 100 N/m2

d. None of these

Which among the following is an assumption of Hagen-Poiseuille equation?

a. Fluid is compressible

b. Fluid is uniform

c. Fluid is laminar

d. Fluid is turbulent

Darcy- Weisbach equation gives relation between

a. Pressure and temperature

b. Mass, volume and pressure

c. Head loss and pressure loss

d. Pressure loss only Question

Which among the following does not depend on the friction factor?

a. Pipe diameter

b. Fluid density

c. Viscosity

d.Gravity

Which of the following are features of a laminar boundary layer?

a. Flow is smooth

b. An increased boundary layer thickness correlate with decreased shear stress

c. An increased boundary layer thickness correlate with increased shear stress

d. A+B.

For any system considered, which of the following statements is correct?

a. Two pumps should be connected in series to increase the flow rate.

b. Two pumps should be connected in series to increase the pump head.

c. Two pumps should be connected in parallel to increase the flow rate.

d. B+C

What are the equations used to find the power of the pump used to pump water from a lower tank to an upper tank

a. Energy and power of the pump equations

b. Energy, continuity, and power of the pump equations

c. Energy, Darcy-Weisbeck, continuity, and power of the pump equations

d. All of these

The Hydraulic radius of a equilateral triangular channel of length is equal to

a. h/6L

b. hL/6

c. h/6

d. L/6h

The friction factor (f) in Moody’s diagram for a turbulent flow is only a function of

a. f (Re, Ks/D) only

b. f (Re, hf) only

c. f (Re, Ks/D, hf) only

d. None of these.

Case (A): The car speed is 5 km/hr Case (B): The car speed is 10 km/hr Assuming the same car in both cases

a. Power in case (B) = power in case (A).

b. Power in case (B) = 2 x power in case (A).

c. Power in case (B) = 4 x power in case (A).

d. Power in case (B) = 8 x power in case (A).

A Pelton wheel is a turbine that is the main component of a hydroelectric power plant. A Pelton wheel is made of a series of buckets arranged in a circular disk as shown in the figure below. A water jet is shot at the buckets and after striking those buckets emerges out at an angle with respect to the initial jet.
A hydroelectric power plant is to be constructed in which water drops from a lake located at an elevation of 100 meters above the Pelton wheel location. You are consulted as an engineer to advise about what size of Pelton wheel (what size of outer diameter) to buy to produce a power output of 500,000 Watts.
The customer that asked for your consultation wants you to design an experiment with a model Pelton wheel that has a diameter of 50 cm.
Design the required experiment (pick values when you need, introduce variables as needed). Suggest to the customer (according to the output of your experiment) what Pelton wheel diameter is needed to produce the power of 500,000 Watts

A house that is losing heat to the 100C outdoors at an average rate of 50,000 kJ/h is maintained at 220C at all
times during a winter night for 10 h. The house is to be heated by 50 glass containers each containing 20 L
(1L=10-3 m3
) of water that is heated to 80oC during the day by a solar heater. A thermostat-controlled 15-kW
back-up electric resistance heater turns on whenever necessary to keep the house at 220C. Analyse and
determine the following:
i. If the average solar intensity is 650 W/m2

and the solar heater has an efficiency of 80%, calculate the

area of solar heater to heat 20L of water from 220C to 800C in 8 hours.
ii. How long did the electric heating system run at night?
iii. Keeping 2nd law of thermodynamics in mind, what is the maximum efficiency of the back-up heater?
iv. If the heat provided by the back-up heater is provided using Carnot heat pump, determine the
reduction in electricity consumption.

Water ( ρ= 1000 kg/m3; Cp= 4.2 kJ/kg.K) at 1,488 kg/hr and 13oC enters a 10-mm-diameter smooth tube whose wall temperature is maintained at 56oC. If the convection heat transfer coefficient is 11,496 W/m2.K, calculate the tube length, in m, necessary to heat the water to 40oC.

Draw moving sound wave and stationary sound wave coordinate system.
From fundamental principles derive speed of sound. Calculate speed of sound in water and iron.

A Food storage locker requires a refrigeration system of 42kW(12TR) capacity at an evaporator temperature of -5°C and condenser temperature of 40°C. The refrigerant, R-12, is sub-cooled 5°C before entering the expansion valve, and the vapour is super-heated 6°C before leaving the evaporator coil. The compression of the refrigerant is isentropic. A two-cylinder vertical single acting compressor with stroke equal to 1.5 times the bore is to be used operating at 960 r.p.m. Determine (i) refrigerating effect/kg. (ii) mass of refrigerant per minute, (iii) theoretical suction volume per minute (iv) theoretical power, (vi) COP, (vi) heat removed through condenser/kg and (vii) theoretical bore and stroke of compressor.

The pressure and temperature at the beginning of the compression are 1 bar and 27°C. Assuming an ideal engine in which the compression ratio and the expansion ratio for a C.I engine are (15+ ? ???) and (8− ? ???) respectively. Determine the mean effective pressure, the ratio of maximum pressure to mean effective pressure and cycle efficiency. Also, find the fuel consumption per kWh if the indicated thermal efficiency is 50% of ideal efficiency, mechanical efficiency is 80% and the calorific value of diesel oil is 42000 kJ/kg. Assume for air: cp = 1.005 kJ/kg K ; cv = 0.718 kJ/kg K, γ = 1.4. [7 Marks] Where n is 17