Please, I want a paragraph about PLA materiel, with a table of properties of PLA.
I need it in an experimental measurement and techniques project. NO PLAGIARISM PLEASE
In: Mechanical Engineering
Q2 A single stage nozzled axial flow gas turbine operates with
1000 K total inlet temperature and 4.8 bar inlet total pressure
with 12 kg/s mass flow rate. The axial velocity throughout the
stage is constant at 220 m/s and the blade speed is 350 m/s. The
nozzle exit and the rotor exit angles are 65° and 7° respectively.
The static pressure at the exit of the stage is 2.5 bar. Assuming
equal inlet and exit absolute flow velocities, determine: (i)
relative flow angle at rotor inlet; (ii) relative velocity at stage
inlet; (iii) relative flow angle at rotor exit; (iv) relative
velocity at stage exit; (v) absolute flow velocity; (vi) degree of
reaction; and (vii) specific power output of the turbine
In: Mechanical Engineering
An electric vehicle has the following parameter values:
mv = 800kg
CD =0.2
Af = 2.2 m2
ρ = 1.18 kg/m
f r = 0.008 + 0.6×10-6×v2 (v: vehicle speed in m/s)
The vehicle is on level road. It accelerates from 0 to 100 km/h in 10s such that its velocity profile is given by v (t) =0.29055t2 for 0 < t < 10s. (The mass factor is assumed unit)
a. Define the traction force expression Ft
b. Sketch Ft versus time
c. Define the instantaneous traction power expression
d. Calculate the energy consumed during the acceleration (0 < t < 10s)
e. Calculate the energy lost for non-conservative forces (wind and rolling resistance)
f. Find the change in kinetic energy and the change in tractive energy during acceleration.
In: Mechanical Engineering
The solid rod shown here has a radius of ?. If it is subjected to the force of ?? at B point, answer the following questions.
Use ??=700 ??; ???=11 ??; ???=15 ??; ???=8 ??; ?=0.7 ??
In: Mechanical Engineering
1. The thermal efficiency of a Rankine power cycle may be
improved by i. Superheating the steam ii. Reheating the steam
between high and lower pressure sections of the turbine iii.
Regenerative Feedwater Heating iv. Insulating the turbine and
decreasing the entropy production during the expansion process v.
Incorporating a Rankine cycle power system as part of a
cogeneration system a. Items i), ii), and iv) only b. Items i),
iii), and v) only c. Items ii), iv) and v) only d. All of these e.
None of these
2. The back work ratio is … a. The ratio of the compressor outlet
to inlet pressure in a vapor compression power system. b. The ratio
of the pump work (power) input divided by the turbine work (power)
output in a Rankine cycle power system. c. The ratio of the inlet
pressure to the outlet pressure in a steam turbine. d. The ratio of
the inlet pressure to the outlet pressure in the feedwater pump
system of a Rankine cycle power system.
3. For the Rankine cycle process where steam expands through the
turbine, in a realistic process, the entropy at the exit is … a.
Greater than the entropy at the inlet. b. Equal to the entropy at
the inlet. c. Less than the entropy at the inlet. d. Has no
relationship to the entropy at the inlet. e. None of
these answers is correct.
4. Regenerative feedwater heaters may be … a. Devices where natural
gas is used to heat feedwater to prevent freezing under cold
conditions. b. Open devices where the steam and the
water being heated are at the same pressure, c. Closed devices
where the steam and the water being heated may be at different
pressures and do not mix, d. Open or closed devices, where both
have their advantages and applications. e. Devices where steam is
diverted, passed back into the steam generator, and then sent back
into the turbine. f. None of the above.
5. With regenerative feedwater heating, a powerplant will not have
more than one stage of feedwater pump (i.e., each feedwater pump
will take in water at condenser pressure and deliver water at steam
generator/turbine inlet pressure). a. True b. False
6. In a power plant, the heat rejected from the condenser … a. Is
not a significant amount of heat, is rejected into the
surroundings, and is not a concern. b. Is a significant
amount of heat and is captured to turn the main
turbine. c. Is a significant amount of heat, is
rejected into the surroundings, and can change the local
environment. d. Heat is not rejected in the condenser.
7. Deaeration is needed in systems using water as a working fluid
to remove air from the water and to minimize corrosion.
a. True b. False
8. A closed feedwater heater may be used for deaeration. a. True b.
False
9. In a reciprocating power system, i. Material flows
at a constant rate through the device and passes through a turbine
to produce shaft power output, ii. Material does not flow at a
constant rate through every section of the device. iii.
Power is produced at all times. iv. Power is produced only during
part of the cycle in each section of the device and is not produced
uniformly at every instant. v. The power unit consists
of one or more piston and cylinder sections with intake and exhaust
valves and where fresh fuel and air are taken in during one part of
the process, exhaust gases are ejected during another part of the
process, and at other times the cylinder is closed off from the
intake and exhaust sections (manifolds). vi. The power
unit consists of a compressor, a burner section, and a
turbine. a. Items i), iii), and vi) are correct. b.
Items ii) and iii) are correct. c. Items ii), iv) and v) are
correct. d. Items ii), iv), and vi) are correct. e. None of these
combinations are correct.
10. The Otto cycle model is used with … a. Reciprocating internal
combustion engines where the fuel-air mixture is ignited by a
spark. b. Reciprocating internal combustion engines where the
fuel-air mixture is ignited by high pressures in the cylinders. c.
Internal combustion engines with continuous flow of fuel and air
(i.e., gas turbine engines). d. External combustion “hot air”
engines. e. Vapor compression refrigeration.
11. In an air standard analysis, we pretend that the substance in
an engine is pure air, and we analyze this as if energy is put into
the air from the outside and, later, waste heat is removed from the
air. a. True b. False
In: Mechanical Engineering
An extruded, rectangular polypropylene strut of width 9 mm, depth 3 mm and length 80 mm is to be loaded from the ends in compression along its length with a creep load of 40 N for one year. [Creep curves for polypropylene are shown below. The buckling load is given by F = (2 p/ L)2 E I. For a rectangular beam the second moment of area is given by I = (w d3) /12.].
In order to improve buckling resistance, explain with reference to the buckling equation, what changes are possible in either material or beam design, indicating any likely constraints on such changes.
Discuss the manufacturing problems (in terms of extruder system design) which must be considered in producing such a beam.
In: Mechanical Engineering
Explain “STANDARDS” and “CODES” by writing their basic characteristics (or essentials) and giving their similarities and differences (if any).
In: Mechanical Engineering
Give some case studies for Mechanical property assessment by nanoindentation technique.
In: Mechanical Engineering
In: Mechanical Engineering
A piston cylinder device with air is going through an isentropic compression. The initial pressure is 0.1 MPa and temperature is 300 K. During the isentropic compression process, the volume is decreased to 1/18 of the initial volume. Using variable specific heats, determine the pressure and temperature at the end of the compression process. What is the amount of work consumed?
In: Mechanical Engineering
Air flows in a converging-diverging nozzle. The nozzle throat area is 50 cm2. The total pressure at the nozzle inlet is 1 MPa. The total pressure at the nozzle exit is 650 kPa. The Mach number at the nozzle exit is 0.70. Find the nozzle exit area.
51.7 cm2
84.2 cm2
35.6 cm2
54.7 cm2
In: Mechanical Engineering
2. In the PLD method, among the mechanisms under which the material is ablated, I wonder what is the conditions for the exfoliation sputtering.
In: Mechanical Engineering
A proposed Ocean Thermal Energy Conversion (OTEC) plant draws heat from the ocean surface at 22°C and rejects heat to the water near the ocean bed at 4°C. What is the highest thermal efficiency the plant could achieve? [4] (b) Consider a system undergoing an adiabatic process from a fixed state 1 to a fixed state 2. Use the Second Law of Thermodynamics to prove that the maximum work is done by the system if the process is reversible. [6] (c) Steam at 20 MPa and 460°C flows at 12 kg/s into an adiabatic turbine and exits at 20 kPa. What is the maximum possible power output of the turbine? What is the temperature of the steam at the exit in that case? [5] (d) Steam at 20 MPa and 460°C flows at 12 kg/s into an adiabatic turbine and exits at 20 kPa and 85% quality. What is the isentropic efficiency of the turbine?
In: Mechanical Engineering
A one-stage rocket takes off from Space and is tasked with entering into a geosynchronous (the
period of orbit is one day) low earth orbit at an altitude of 2,000km above the surface of the Earth. The mass of the
rocket is 550,000kg,
a) At what final speed does the rocket need to be moving to achieve the specified orbit?
b) If the exhaust velocity of the fuel is 2.20x103m/s what percentage of the rocket’s mass must be fuel?
c) Given that the rocket expends fuel at a rate of 1.4x104kg/s would this rocket be appropriate for manned flights?
In: Mechanical Engineering
kindly do the stability analysis ( longitudnal, lateral stability) lift and moment coefficient for boeing 787 or boeing 777 aircraft.
In: Mechanical Engineering