Draw a free body diagram of a piston, connecting rod and crank shaft. Indicate on the diagram the effective forces acting on the piston and the crank shaft during the expansion stroke. Now let’s do some sample calculations assume 2500 RPM and neglecting friction.
b. For a compression ignition engine with a 200mm bore, a compression ratio of rc = 20, and a cylinder pressure of 100 bar when the crank shaft is at θ = 0°, 45° and 90°. You can assume that the S/B = 1 and l/a = 3, that the piston has a mass of 1 kg, and for simplicity that the expansion of the hot gas from TDC to BDC is isentropic with k =1.4
Second sentence.
In: Mechanical Engineering
A steam turbine is to operate on a simple regenerative cycle.
Steam is
supplied dry saturated at 40 bar, and is exhausted to condenser at
0.07 bar.
The condensate is pumped to pressure of 3.5 bar at which it is
mixed with
bleed steam from the turbine at 3.5 bar. The resulting water which
is at
saturated temperature is pumped to boiler. For the ideal cycle
calculate,
neglecting the feed pump work.
3 | P a g e
I. The amount of bleed steam required per kilogram of supply steam
[2
marks]
II. The cycle efficiency of plant [2 marks]
III. The specific steam consumption [1 marks]
IV. Draw T-s and schematic diagram of this cycle [2 marks]
Part B: [CLO:1]
V. What type of regenerator is used in this cycle? [1 marks]
VI. Discuss feasibility of Reheating in this plant [2 marks]
In: Mechanical Engineering
heat transfer question, show equations, assumptions, calculations and steps clearly. will give thumbs up rating if solved correctly in 50 minutes
part a:
What is the Lumped Capacitance Method, what does it assume, and for which criteria is it valid?
part b:
When part of a system is perfectly insulated, how do we translate this mathematically as a boundary condition?
part c:
State three important assumptions that must be respected for the thermal resistance concept to be valid in a plane wall.
In: Mechanical Engineering
Air is compressed from an inlet condition of 100 kPa, 300 K to an exit pressure of 1000 kPa by an internally reversible compressor. Determine the compressor power per unit mass flow rate if the device is
(a) isentropic,
(b) polytropic with n =1.3,
(c) isothermal.
In: Mechanical Engineering
International Capital, Inc. (IC), is a small investment banking firm that specializes in securing funds for small- to medium-sized firms. IC uses a standardized project format for each engagement
Activity |
Description |
Predecessor |
a opt |
m ml |
b pess |
||
1 |
Start story draft using template |
None |
9 |
12 |
16 |
||
2 |
Research client firm |
None |
6 |
12 |
14 |
||
3 |
Create “due diligence” rough draft |
1, 2 |
8 |
12 |
20 |
||
4 |
Coordinate needs proposal with client |
3 |
20 |
24 |
32 |
||
5 |
Estimate future demand and cash flows |
3 |
14 |
16 |
35 |
||
6 |
Draft future plans for client company |
5 |
8 |
14 |
18 |
||
7 |
Create and approve legal documents |
3 |
12 |
18 |
34 |
||
8 |
Integrate all drafts into first-draft proposal |
4, 6, 7 |
10 |
14 |
18 |
||
9 |
Line up potential sources of capital |
7, 6 |
8 |
16 |
24 |
||
10 |
Check, approve, and print final legal proposal |
8 |
8 |
10 |
18 |
||
11 |
Sign contracts and transfer funds |
9, 10 |
18 |
26 |
42 |
In: Mechanical Engineering
consider a column that is fixed at the base and which
is pinned at the top. The differential equation for this system
is
d^2v/dx^2 + k^2v= R/El ( L -x);k^2=P/EI
it is known that the smallest critical load is
P1= 20.19EI/ L^2.
for this system determine the second smallest critical load P2 and
express this as the numerical ratio P2/P1.
In: Mechanical Engineering
In a household refrigerator with evaporator temperature -10 ° C and condenser pressure 1000 kPa R134a is used as refrigerant. Saturated steam at the compressor inlet The refrigerant that is in the state is in the state of saturated liquid at the outlet of the condenser. Entropy at the compressor outlet is 0.985 kJ / kgK. According to this,
a) Cycle T-s and P-h diagrams, showing saturation curves on the diagram Draw.
b) Calculate the isentropic efficiency of the compressor.
c) Find the cooling performance coefficient of the refrigerator.
d) What is the second law efficiency of this refrigerator?
PLEASE EXPLAİN STEP BY STEP
In: Mechanical Engineering
Five mutually-exclusive projects consisting of reinforcing dams, levees, and embankments are available for funding by a certain public agency. The following tabulation shows the equivalent annual benefits and costs for each: Project Annual Benefits Annual Costs A $1,800,000 $2,000,000 B $5,600,000 $4.200,000 C $8,400,000 $6,800,000 D $2,600,000 $2,800,000 E $6,600,000 $5,400,000 Assume that the projects are of the type for which the benefits can be determined with considerable certainty and that the agency is willing to invest money in any project as long as the B-C ratio is at least one. Determine the annual worth (AW) of the best project that the public agency will select. The agency’s MARR is 10 % per year and the project lifetimes are each 15 years.
In: Mechanical Engineering
A 15/16 in. wide key has depth of 5/8 in. It is 12 inches long and is to be used on a 200 hp, 1160 rpm, squirrel-cage induction motor. The shaft diameter of 3 7/8 inches. The maximum running torque is 200% of the full-load torque. Compute the maximum torque (ans: 21,733 in-lb) Please show solution.
In: Mechanical Engineering
Air is compressed from an inlet condition of 100 kPa, 300 K to
an exit pressure of 1000 kPa by an internally reversible
compressor. Determine the compressor power per unit mass flow rate
if the device is
(a) isentropic,
(b) polytropic with n =1.3,
(c) isothermal.
In: Mechanical Engineering
A person without a lower limb or limbs may face huge cost to get prosthetic legs. A metal prosthesis can cost up to RM10,000 depending on the specifications and requirement of the patient. Cane furniture was made by bending the stem in such beautiful shapes that could also hold human weight. The usage of sustainable materials such as cane may help the sustainability of life of a person without a limb by ensuring it is affordable and available to people of all levels as well as helped the sustainability of the environment. However, one question - can you make a leg out of a cane? Discuss.
In: Mechanical Engineering
(20) A 15kW electric motor, which is running at 43 rev/s, is used to drive a crusher which operates 24 hours per day. An engineer has specified 212 mm and 315 mm pitch diameters for small pulley and large pulley respectively; and C 3454 V-belt type.
a) Calculate allowable power, design power and required number of belts. (Take design factor nd as 1.)
In: Mechanical Engineering
In a gas turbine generating station the overall compression ratio is 12/1, performed in three stages with pressure ratios of 2.5/1, 2.4/1, and 2/1 respectively. The air inlet temperature to the plant is 25 ℃ and intercooling between the stages reduces the temperature to 40 ℃. The HP turbine drives the HP and intermediate-pressure compressor stages; the LP turbine drives the LP compressor and the generator. The gases leaving the LP turbine passed through the heat exchanger which heats the air leaving the HP compressor. The temperature at inlet to the HP turbine is 650 ℃, and reheating between the turbine stages raises the temperature to 650 ℃. The gases leaves the heat exchanger at a temperature of 200 ℃. The isentropic efficiency of each compressor stage in 0.83, and isentropic efficiencies of HP and LP turbines are 0.85 and 0.88 respectively. Take the mechanical efficiency of each shaft as 0.98. The air mass flow is 140 kg/s. Neglecting the pressure losses and changes in kinetic energy, and taking the specific heat of water as 4.19 kJ/kg.K, and take Cp and γ for air to be 1.005 kJ/kg.K and 1.4 respectively. calculate. (a) The power output in kilowatts; [2 marks] (b) The cycle efficiency; [2 marks] (c) The flow of cooling water required for the intercoolers when the rise in water temperature must not exceeded 40 K; [2 marks] (d) The thermal ratio of heat exchanger [2 marks] (e) Draw the T-s diagram [2 marks]
In: Mechanical Engineering
A 20kW electric motor, which is running at 43 rev/s, is used to drive a crusher that operates 24 hours per day. An engineer has specified 212 mm and 315 mm pitch diameters for the small pulley and large pulley respectively; and C 3454 V-belt type.
a) What should be the conservative service factor for this belt and pulley system?
b) Calculate the center distance between the pulleys?
c) Calculate allowable power, design power, and required number of belts. (Take design factor nd as 1.)
d) Calculate centrifugal tension, forces at tension side and loose side, initial tension, and factor of safety. (Take friction coefficient including wedge effect as 0.5123.)
In: Mechanical Engineering
Suppose the Gulfstream G550 is cruising at an altitude and of 41,000 feet. and 559 miles per hour, respectively. If the plane currently weighs 74,950 pounds, how much thrust is required to maintain these flight conditions? The wingspan is 91.5 feet and the wing platform area is 1,137 square feet. The Oswald efficiency factor is 0.9 and the zero-lift drag coefficient is 0.0165.
In: Mechanical Engineering