In: Mechanical Engineering
At steady state, 100 m^3/min of dry air at 32 C, 1 bar is mixed adiabatically with a stream of oxygen at 127 C, 1 bar to form a mixed stream at 47 C, 1 bar. Kinetic and potential energy effects can be ignored.
Find:
(a) the mass flow rates of the dry air and the oxygen
(b) the mole fractions of the dry air and oxygen in the exiting mixture
(c) the time rate of entropy production
In: Mechanical Engineering
Argon gas is initially at a pressure of 10 bar and temperature of 45oC (state 1), while occupying a volume of 0.8 m3 in a frictionless piston-cylinder arrangement. The gas then undergoes a reversible constant volume process to a pressure of 6 bar (state 2), followed by a constant pressure process in which the temperature is restored to 45oC (state 3). a) Sketch the processes on T-s and p-v diagrams b) Assuming perfect gas behaviour determine i) The work done by each process. ii) The heat transfer during each process. iii) The change in entropy in process state 3 to 1. (For Argon take Cp = 519.6 J.kg^-1K^-1 and relative molar mass M=40
In: Mechanical Engineering
compressible flow:
a converging-diverging nozzle has an area ratio of 5 and a stagnation pressure of 1 MPa. Assume that the gas in the nozzle behaves exactly like air. Which of the following most accurately gives the range of nozzle exit pressures for which the flow is choked, but has subsonic flow at the nozzle exit?
a)990 kPa ?? 1 MPa
b)244 kPa ?? 1 MPa
c)21 kPa ?? 1MPa
d)1 kPa ?? 1 MPa
e)244 kPa ?? 990 kPa
f)21 kPa ?? 990 kPa
g)1 kPa ?? 990 kPa
h)21 kPa ?? 244 kPa
i)1 kPa ?? 244 kPa
j)1 kPa ?? 21 kPa
In: Mechanical Engineering
in c++ (Sum, average and product of numbers in a file) Suppose that a text file Exercise13_3.txt contains six integers. Write a program that reads integers from the file and displays their sum, average and product. Integers are separated by blanks.
Instead of displaying the results on the screen, send the results to an output named using your last name.
Example:
Contents of Exercise13_3.txt:
|
Contents of YourLastName.txt:
|
Run the program for the example above and for another example with 15 scores.
In: Mechanical Engineering
2-) Given the following data:
Drilling Fluid Density : 12 ppg
Well Depth: 10,000 ft.
Drill Bit Nozzle Sizes: 13-13-13
Pump Horsepower: 1800
Pump Volumetric Efficiency: 80%
Maximum Pump Pressure: 4,500 psi
Minimum Flow Rate: 350 gpm
Parasitic pressure losses of 2,173 psi and 1,388 psi are anticipated while circulating mud at flow rates 500 gpm and 390 gpm respectively.
a-) Determine the parasitic pressure losses when the bit hydraulic horsepower is maximum.
b-) Determine the optimum flow rate when the bit hydraulic horsepower is maximum.
c-)Determine the pressure drop across bit nozzles when the bit hydraulic horsepower is maximum.
d-) Determine the optimum sizes of three nozzles to be used for the next bit run using the maximum bit hydraulic horsepower criteria.
In: Mechanical Engineering
Air enters a counterflow heat exchanger operating at steady state at 22°C, 0.1 MPa and exits at 7°C. Refrigerant 134a enters at 0.2 MPa, a quality of 0.33, and a mass flow rate of 30 kg/h. Refrigerant exits at 0°C. There is no significant change in pressure for either stream.
(a) For the Refrigerant 134a stream, determine the rate of heat transfer, in kJ/h |
(b) For the refrigerant stream evaluate the change in flow exergy rate, in kJ/h. |
(c) For the air stream evaluate the change in flow exergy rate, in kJ/h. |
Let T0 = 22°C, p0 = 0.1
MPa, and ignore the effects of motion and gravity.
Round your answers to 3 significant digits.
In: Mechanical Engineering
Slab milling is performed on the top surface of a rectangular workpiece that is 12.0 in long by 2.5 in wide by 4.0 in thick. The helical milling cutter, which has a 3.0-in diameter and eight teeth overhangs the width of the part on both sides. Cutting speed = 125 ft/min, feed = 0.006 in/tooth, and depth of cut = 0.300 in. Determine (a) machining time, in min, and
(b) maximum metal removal rate during the cut.
in in3/min
(c) If an additional approach distance of 0.5 in is provided at the beginning of the pass (before cutting begins), and an overtravel distance is provided at the end of the pass equal to the cutter radius plus 0.5 in, what is the duration of the feed motion.
Enter your answer
min
In: Mechanical Engineering
1) In an air-standard Brayton cycle, the air enters the compressor at 0.1 MPa and 15?C. The pressure leaving the compressor is 1.0 MPa, and the maximum temperature in the cycle is 1100?C. Determine The pressure and temperature at each point in the cycle. The compressor work, turbine work, and cycle efficiency. For each control volume analysed, the model is ideal gas with constant specific heat at 300 K, and each process is steady state with no kinetic or potential energy changes.
2) A utility runs a Rankine cycle with a water boiler at 3MPa, and the highest and lowest temperatures of the cycle are 450?C and 45?C, respectively. Find the plant efficiency and the efficiency of a Carnot cycle with the same temperatures.
3) A single stage air compressor running at 80 RPM, compress air from a pressure of 1 bar and temperature of 15oC to a pressure of 5 bar. The clearance volume is 5 % of swept volume which is 0.42 m3 . Assuming that the compression and expansion to follow the law, PV(1.3)= constant. Determine volumetric efficiency, mass of air delivered in kg/sec, exit temperature of air and the power required to drive the compressor in KW.
4) The velocity of steam at inlet to a simple impulse turbine is 1000 m/s, and the nozzle angle is 20o. The blade speed is 400 m/s and the blades are symmetrical. Determine the blade angle if the steam is to enter the blade without shock. If the relative velocity at exit is reduced by friction to 80% of that at inlet, what are then the diagram power and the axial thrust for a mass flow of 0.75 kg/s? Calculate also the diagram efficiency in this case.
5) The nozzle of the impulse stage of a turbine receives steam at 15 bar and 300oC and discharges at 10 bar. The nozzle efficiency is 95% and the nozzle angle is 20 o . The blade speed is that required for maximum work and the inlet angle of the blades is that required for entry of the steam without shock. The blade exit angle is 5o less than the inlet angle. The blade velocity coefficient is 0.9. Calculate for a steam flow of 1350 kg/h: The diagram power; The diagram efficiency.
In: Mechanical Engineering
In: Mechanical Engineering
A roller chain drive is to transmit a design power of 9.0 kW with the faster shaft having a speed of 84 rpm. Select the most suitable chain size and type of lubrication from the following options if the pinion has 15 teeth:
1 - Pitch of 25.4 mm, oil bath or disc lubrication,
2 - Pitch of 19 mm, drip feed lubrication,
3 - Pitch of 25.4 mm, drip feed lubrication,
4 - Pitch of 19 mm, drip feed lubrication,
In: Mechanical Engineering
Discuss this statement in detail within the context of the
Malaysian environment. Very
often codes of practices suggest discretion of engineering
judgement. There are merits
and demerits of international codes of practice and standards as
opposed to national
documents within the context of the Malaysian industry and
practices. Discuss by
giving examples of engineering judgement whereby such decisions
does not conform
to an international code of practices and how it is justified. Is
international conformity
always desirable?
In: Mechanical Engineering
4a- Explain what typical vibration problems you would expect to see monitoring a high frequency bandwidth of 2000Hz to 10000Hz, and what typical problems you can expect to see with a low frequency bandwidth of 2Hz to 1000Hz. 4b-Lack of lubrication within rolling element bearings can result in excessive metal-to-metal contact. How would you determine this was occurring using vibration analysis—provide spectra to illustrate your answer? What role does high frequency filtering techniques like amplitude demodulation play in analysing a lack of lubrication situation?
In: Mechanical Engineering
Five kg of butane (C4H10) in a piston–cylinder assembly undergo a process from p1 = 5 MPa, T1 = 500 K to p2 = 2 MPa, T2 = 450 K during which the relationship between pressure and specific volume is pvn = constant. Determine the work, in kJ.
In: Mechanical Engineering
Describe in detail how SARA analysis is conducted. What is its significance? Describe the role of Asphaltene in crude oil emulsion stabilization mechanism. How does the presence of Resin affect the Asphaltene stabilization process? (please provide resources)
In: Mechanical Engineering