0
Mechanical Engineering
Mechanical Engineering is a branch of engineering that encompasses the generation and application of heat and mechanical power and the design, production, and use of machines and tools. Mechanical engineering involves application of the principles of dynamics, control, thermodynamics and heat transfer, fluid mechanics, strength of materials, materials science, electronics, and mathematics.
10,989 Questions
What is hot end corrosion in boilers?
One of the problems with heat recovery boilers behind incinerators of solid,liquid or municipal solid wastes is high temperature corrosion associated with the formation of complex eutectics which have a low melting point and deposit as slag on boiler heating surfaces.This is difficult to get rid of and results in high temperature corrosion,fouling problems and consequent higher exit gas temperature from the boiler and consequent lower steam generation.Another concern in these applications is the presence of corrosive gases such as chlorine and hydrogen chloride,which corrode the boiler tubes,particularly those operating above 800 F,resulting in tube thinning and failure
Does a dynamo have mechanical load or does it rotate freely without much efforts like a bearing?
It rotates freely until it is required to do work. As soon as a load is placed across the output more effort will be required to rotate the Dynamo.
faggio
What Filler metal is used for p-91 Chrome?
For GTAW Process use ER90-B9 and for the SMAW Process use E 9018-B9, or E 9015-B9
What is the difference between animatronics and robotics?
Nothing! Animatronics is Biomorphic Robotics.
What is the cutting speed of solid carbide drills?
It depends on the diameter of the drill and the type of material being drilled.
What does it mean if a material has a high Yield Stress value?
In colloquial terms, it is "strong". It can take a high load, and return back to an undamaged, undeformed state afterward. If the yield strength is equal to or very close to the ultimate tensile strength, common when it is a very high value, that indicates the material is not very ductile. Glass is a material like this. You can load it very high, but it will break rather than "stretch".
What basic operations must a steering system enable the driver to carry out?
The first thing that comes to mind is the shift gear.....from P (park) to either R or F. That baby ain't goin' nowhere until one of those things is done.
Why is a screw head bigger than the screw shaft?
The screw head is larger to prevent the screw from pulling threw the hole made by the shaft
Factors influencing quality and intensity of xray?
Power of the X-ray tube, voltage applied, current intensity, anticathode type, filters, collimator, tube design, working atmosphere, etc.
For incompressible flow the inviscid 1D Euler equations decouple to:
ρt
+ uρx
=
0
px
=0
ut
+
ρ
et
+ uex
=
0
The 3D Euler equations are given by
ρw
ρv
ρu
ρ
ρuw
ρuv
ρu2 + p
ρu
ρv
+ ρuv
+ ρv
2 + p + ρvw
=
0
ρw2 + p
ρvw
ρuw
ρw
(E + p)w
z
(E + p)v
y
(E + p)u
x
E t
where ρ is the density, u =
(u, v, w) are the velocities, E is the total energy per unit volume and p is the
pressure. The total energy is the sum of the internal energy and the kinetic energy.
(
)
1
2
E =ρ
e+
u
2
where e is the internal energy per unit mass. The assumption of incompressiblity
gives
Show that in 3D the inviscid Euler equations with the assumption of incompressible flow decouple to:
The mass conservation equation takes the form:
=
ρe
+ ρ(u2 + v 2 + w2 )/2
∇ · u =
ux
+ vy
+ wz
=
0,
ρt
+ u · ∇ρ
=
0
px
=0
ut
+ u · ∇u
+
ρ
py
vt
+ u · ∇v
+
=0
ρ
pz
wt + u · ∇w
+
=0
ρ
et
+ u · ∇e
=
0
0 =
ρt
+ ∇ · (ρu)
=
ρt
+ ρ∇
· u + u · ∇ρ
=
ρt
+ u · ∇ρ
=
0 .
The momentum equation along the x-axis
can be condensed into
0 =
(ρu)t
+ (ρu2 )x + (ρuv)y
+ (ρuw)z
+ px
=
ρut
+ uρt
+ ρuux
+ u(ρu)x
+ ρvuy
+ u(ρv)y
+ ρwuz
+ u(ρw)z
+ px
=
ρut
+ ρuux
+ ρvuy
+ ρwuz
+ px
+ (ρt
+ (ρv)y
+ (ρu)x
+ (ρw)z
)
=
ρut
+ ρu
· ∇u
+ px
+ (ρt
+ ∇ · (ρu))
⇒ ut
+ u · ∇u
+
px
=0.
ρ
1
A similar argument reveals that the y- and z-axis
momentum equations reduce to their appropriate equations,
giving (in vector form):
∇p
(3)
⇒ ut
+ (u · ∇)u
+
=0.
ρ
Finally, The energy equation can be manipulated in the following way:
0 =
Et
+ ∇ · [(E + p)u]
=
Et
+ ∇ · (Eu) + ∇ · (pu)
=
Et
+ E∇ · u + u · ∇E + p∇
· u + u · ∇p
(
)
(
)
(
)
1
1
1
=
ρ e + u · u + ρt
e + u · u + u · ∇ ρe
+ ρ u · u + u · ∇p
2
2
2
t
(
)
(
)
1
1
=
ρet
+ ρu
· ut
+ ρt
e + u · u + u · ∇(ρe)
+ u · ∇ ρ u · u + u · ∇p
2
2
(
)
(
)
1
1
=
ρet
+ ρu
· ut
+ ρt
e + u · u + ρu
· ∇e
+ eu
· ∇ρ
+
u · u u · ∇ρ
+ ρu
· (u · ∇u)
+ u · ∇p
2
2
)
(
)
(
∇p
1
=
ρet
+ ρu
· ∇e
+ e + u · u (ρt
+ u · ∇ρ)
+ ρu
· ut
+ u · ∇u
+
2
ρ
⇒ et
+ u · ∇e
=
0 .
heat strain or the thermal strain is caused due to the temperature changes. A solid body expands as the temperature increases and contracts as the temperature decreases.this causes the thermal strain. for a homogeneous and isotropic body the thermal strain is caused by change in temperature. thermal strain = coefficient of linear thermal expansion * change in temperature
where the coefficient of linear thermal expansion gives the strain per degree of temperature.
Metallurgical lenght for Continuous casting machines for steel?
it is that length in which steel completely solidify in continuous casting process
That is a question that does not have one single answer. For instance, if the pressure of the steam is raised, less steam is needed. As pressure rises, temperature will also rise due to adiabatic work done on the steam. Also, higher temperatures are needed at higher pressures to make sure the steam does not condense. Raising the temperature of the steam at a given pressure also means that less steam is needed to provide the same amount of energy. Efficiency will also vary, depending on the turbine, and other factors, such ascondenser vacuum.
In general, running a pressure around 40 - 45 PSI, it will take 20,000 - 25,000 pounds of steam per hour to generate one megawatt of electricity during that hour. This is with steam that is just above saturation (around 285°F). So, for 5 MW, you'd need around 100,000 pounds of steam an hour. The pipe size would depend on the turbine. A 55 MW turbine (common for geothermal), might have two pipes bringing steam in (one per side), both of which are around 30" in diameter. For 100,000 pounds of steam an hour, much smaller pipes would suffice. However, expanding and then compressing the steam repeatedly is something you want to avoid.
Note that these figures reflect more of a geothermal application. The pressure and temperature of steam from a boiler will typically be much higher.
Why drilling with vertical drill machine is more efficient than lathe machine?
For simple drilling, the vertical drill press is faster to use.
How much does an autobody tech get paid a day?
1 to 5 years 100$ per day
5to 10 years 200$
10 to 20 years 250$ to 350$
How many tons can a one meter square 20mm thick steel plate hold?
Firstly the question needs to be defined further:
-How is the load applied, distributed or point loading?
-How is the steel plate supported one edge, two edges , three edges or all four?
Automatic induction braking system for vehicle?
I don't see why not. It would have to be electromagets providing the magnetic field, and they would draw electricity from a generator that is powered by the motor. For electric cars, however, the brakes would draw too much power and drain the battery.
What is the modulating frequency of amplitude modulation?
the frequency range of an am wave is 20herz to 20kilo herz
Explain the significance of 0.2 percent offset in the stress strain diagram?
Theoretically, the yield strength of the material is the stress at which the stress-strain curve stops being linear. In actual testing of most materials, the transition to non-linear is not very clear in that area. The .2% offset line is used to intercept a yield stress for reporting a yield strength. Though arbitrary to a certain extent, it has become the traditional method.
What happens if suction strainer is choked in centrifugal pump?
kwh consumption of the driver of the pump will increase.
Is the pressure in a hydraulic jack the same everywhere?
No, it will depend on leak-tightness, viscosity of oil etc.
