A homogeneous sphere S, a uniform cylinder C, and a thin pipe P are in contact when they are released from rest on the incline shown. Knowing that all three objects roll without slipping, determine, after 9s of motion, if theta=27 degrees, Find
1. acceleration of sphere down the incline
(m/s^2)
2. acceleration of pipe down the incline (m/s^2)
3. The distance between the centers of the cylinder and the sphere
(m)
4. Acceleration of cylinder down the incline (m/s^2)
5. the distance between the centers of the pipe and the cylinder
(m)
In: Mechanical Engineering
Fill in the given blanks with an appropriate word(s).
1.As a general rule of thumb, a location is considered good for
construction of wind turbines if the average wind power density is
about - - - - - -
2.The temperature of geothermal water should be - - - - - - for
cooling applications for reasonable values of performance
factor.
2.In a Lancashire steam boiler, there is a - - - - - - at the
end of the fire grate which is utilized in deflecting the flue
gases upwards.
4.There are geothermal resources named - - - - - -contain hot
liquid water at temperatures up to 450 K and pressures up to 60
MPa.
5.There are fine flat plates in the combustion chamber of a
single-ended scotch marine boiler. These plates require - - - - -
-
6.The main objective of the - - - - - - is to protect the turbines
against the water hammer effect at the time of starting or shutting
off the hydroelectric power plant.
7.Based on the furnace position, Cornish boiler is classified as -
- - - - -
In: Mechanical Engineering
Steam enters the nozzle of an impulse turbine stage at 60 bar and 500 °C and leaves at 20 bar. Flow is adiabatic and reversible. The nozzle angle is 20°. The moving blade is symmetric, travels at optimum velocity, and assumed to be frictionless. It is also assumed that there is neither expansion nor contraction of the steam flow through the blade passage. Draw the velocity diagram and calculate (a) the blade efficiency and (b) the stage efficiency.
In: Mechanical Engineering
Steel Structures
The rolling process is one of the most frequently used forming processes for producing steel sections. Nonetheless, other forming and fabrication processes can be used to create a range of section shapes in the steel production process. For this assignment, you are required to review the other four types of steel forming/fabricating processes including drawing (manufacturing), extrusion, casting and forging.
Task 1(IN YOUR WORDS) : answer in 250 words)
Review the drawing (manufacturing) process and mention the type of section(s) produced from this process. You should also mention the limitation(s) of this process.
In: Mechanical Engineering
ROUND UP TO 4 DECIMAL PLACES. Draw and label the P-V & T-S diagrams.
Given an ideal air-standard Diesel cycle has a compression ratio of 15. Temperature and Pressure at the start of compression process is 70°F and 1atm. 800 BTU/lbm of Heat is added to the system. Determine (a) Temperature, specific volume and Pressure at each state, (b) Efficiency, and (c) the mass flow rate of air (lbm/min), required to produce 200 hp.
In: Mechanical Engineering
A hot liquid is filled in a spherical tank with an inner
diameter of 3 m and a wall thickness of 3 cm. The tank wall is made
of a material with a thermal conductivity of 0.15 W/m∙K. The hot
liquid in the tank causes the inner surface temperature to be
100°C, while the tank outer surface is exposed to air at 20°C and
has an emissivity of 0.35. Determine the outer surface temperature
of the tank. Assume that the properties of air can be evaluated at
40°C and 1 atm pressure. Is this a good assumption?
In: Mechanical Engineering
1. What functions are performed by the flutes on a standard
twist drill?
2. Basically, what determines what helix angle a drill should
have?
3. When a large-diameter hole is to be drilled, why is a smaller
diameter hole often drilled first?
4. What is the function of the margins on a twist drill?
5. What are the primary purposes of reaming?
6. What are the purposes of:
a. Spot facing
b. Counterboring
c. Countersinking
7. Suppose you want to drill a 2-in. thick plate of cast steel
(0.4%C), 4-in. diameter hole. An indexable HSS insert drill has
been selected. Consider the table below, select the appropriate
cutting speed, feed rate. Calculate the spindle speed (rpm), the
feed rate (in/min), the MRR, and cutting time. Assume the cutting
process will be performed in 3 steps using 3 drills sizes in
sequence 1”, then 2”, then 4”. Calculate the cutting total cutting
time, considering a proper allowance each time.
8. How much time will be required for milling machine to face mill
an AISI 1020 steel surface BHN 150, that is 12 in. long and 5 in.
wide, using a 6 in. diameter, eight-tooth tungsten carbide
inserted-tooth face mill cutter? Select values of feed per tooth
and cutting speed from the provided table, Table 24-1.
9. Draw in two sketches the up milling (conventional milling) and
down milling (climb cut) machining set up and show the shape of
machined material.
10. Why does down milling dull the cutter more rapidly than up
milling when machining sand casting iron?
In: Mechanical Engineering
HEAT TRANSFER QUESTION
A shell-and-tube heat exchanger with one shell pass and four tube passes, that contains 190 pipes (thin walled, 4m long, 2.6 cm diameter), will be used to heat the air. Water enters the pipes at 350 K with 8kg/s mass flow rate while the air enters the shell at 15 C with 18kg/s mass flow rate. In time there will be a fouling factor of 0.0026m2K/W on the inside of pipes. Inside heat transfer coefficient is 450 W/m2K, outside heat transfer coefficient is 200 W/m2K. Using the specific heat values for water and air at 25 C.
Find
a)Effectiveness of HX
b) Heat transfer rate (kW)
c) Exit temperatures of air and water, and show one T-L diagram
In: Mechanical Engineering
Consider four identical circular Euler columns under a compressive axial load with a) one end fixed and the other pinned (or hinged or simply-supported), b) both ends fixed, c) both ends pinned (or hinged or simply-supported), d) one end fixed and the other free. What are the buckling loads Pcr for each one and which one is the strongest against buckling? Given are: the length L of the column and bending rigidity EI, ?
In: Mechanical Engineering
What is your understanding on developed, developing and under
develop country? Give
an example of each type of the country.
In: Mechanical Engineering
Two equal-length springs are “nested” together in order to form a shock absorber. If it is designed to arrest the motion of a 2-kg mass that is dropped above the top of the springs from an at-rest position, and the maximum compression of the springs is to be 0.2 m, determine the required stiffness of the inner spring, K B if the outer spring has a stiffness k A = 400 N/m
(s) is unknown, please will you show all the working out. Thank you
In: Mechanical Engineering
Sketch a diagram of an air-water system that uses fan coils around the perimeter and an overhead air distribution system from a central air handler. Show the chiller, and water distribution pumps. Explain the operation of the system in summer season.?
In: Mechanical Engineering
A wet cooling tower is to cool 25 kg/sec of cooling water from 40oC to 25oC at a location where the atmospheric pressure remains constant at 97 kPa. Atmospheric air enters the tower at 25oC and 65% relative humidity and leaves saturated at 35oC. Neglecting the power input to the fan, determine the mass flow rate of the required makeup water.
In: Mechanical Engineering
Air flows in a pipe under fully developed conditions with an average velocity of 1.25 m/s and a temperature of 16°C. The pipe’s inner diameter is 4 cm, and its length is 4 m. The first half of the pipe is kept at a constant wall temperature of 100°C. The second half of the pipe is subjected to a constant heat flux of 200 W. The properties of air at 80°C are ρ = 0.9994 kg/m3, k = 0.02953 W/m·K, v = 2.097 × 10–5 m2/s, cp = 1008 J/kg·K, and Pr = 0.7154.
Determine the wall temperature at the exit of the tube.
In: Mechanical Engineering
A hot-rolled steel bar is subjected to a repeated axial tensile load as shown. The material has ultimate tensile stress S_ut=1300MPa. The bar has a diameter of 30mm. The notch sensitivity factor, theoretical stress concentration factor, and factor of safety are q=0.52,K_t=2.42 and n=1 respectively. Find the maximum force F that the bar can carry for 10^4 cycles at 90% reliability
Figures 10 Points
Endurance limit 10 Point
Endurance strength 10 Points
Fatigue stress concentration factor 5points
Determination of force 15points
In: Mechanical Engineering