Questions
How to calibrate portable CMM(Coordinate Measuring Machine)?

How to calibrate portable CMM(Coordinate Measuring Machine)?

In: Mechanical Engineering

thermodynamics show whey with equations Cv can be calculated using enthalpy while Cp using the internal...

thermodynamics

show whey with equations Cv can be calculated using enthalpy while Cp using the internal energy

In: Mechanical Engineering

A 5-cylinder square engine with a total stroke volume of 3.5 liters, operating according to a...

A 5-cylinder square engine with a total stroke volume of 3.5 liters, operating according to a 4-stroke cycle, operates at 2500 rpm. Since the mechanical efficiency of the engine is 62% and the Indicative work produced for each cylinder is 1 kJ, find the specific power of the engine in kW / cm2.

In: Mechanical Engineering

I need information about “Shear strain application” I have report about it and i cant find...

I need information about “Shear strain application” I have report about it and i cant find anything .. I need about 3 pages ..

In: Mechanical Engineering

In the flow around a cylinder, boundary layer separation occurs due to (SELECT CORRECT ANSWER) energy...

In the flow around a cylinder, boundary layer separation occurs due to (SELECT CORRECT ANSWER)

energy losses in the boundary layer that prevent it from remaining attached.

the Mach number being too high

the surface being rough

a low buoyancy force.

A boundary layer is

a)

a region of flow close to a surface where viscous effects dominate the physics of the flow.

b)

a region of flow that has high turbulence.

c)

important in providing a slip condition at the wall.

d)

increases the velocity of the flow towards the wall

Two flows may be classified as having dynamic similarity if

a)

both cases have equal drag force

b)

both geometries and key dimensionless parameters (i.e. Reynolds numbers) are the same.

c)

both velocities of the flow are the same.

d)

both cases have identical geometry but different size.

In: Mechanical Engineering

8: There is a boundary between a system A with a low temperature TL = 25...

8: There is a boundary between a system A with a low temperature TL = 25 C and another system B with a high temperature TH = 89 C. The surrounding of the two systems has an equilibrium temperature 15 C.
a: Schematically sketch the transfer diagrams of temperature, heat, entropy, and exergy across the boundary between A and B.
b: Calculate the entropy at B and the entropy generation if the entropy at A is 2.9 kJ/K.
c: Calculate the exergy at B and the exergy destruction during the process.

In: Mechanical Engineering

Air at 1 atm and 80 ºC is used for the fluidization of catalyst pellets in...

Air at 1 atm and 80 ºC is used for the fluidization of catalyst pellets in 2.5 mm diameter in a vertical cylindrical reactor. The density of the catalyst particles is 3000 kg/m3. The catalyst particles have a sphericity (Øs) of 0.8 and . What should be the minimum limit of the air velocity? Explain the reasons

b) If the air flow rate is 45000 kg/h and the operational air velocity is 1.5 Vt, what should be the reactor diameter? Viscosity of air is 2.1x10-5 kg/m.s

In: Mechanical Engineering

A roller coaster starts from rest at A, rolls down the track to B, describes a...

A roller coaster starts from rest at A, rolls down the track to B, describes a circular loop of 12-m diameter, and travels up and down past point E. Assume that there is no energy loss due to friction. Given: h = 20 m. Shoe the free body diagrams at points B,D, and E. Determine the force exerted by his seat by a 80 kg rider at B and D and the minimum value of the radius of curvature at E if the roller coaster is not to leave the track at that point.

In: Mechanical Engineering

Write a report on the security threats faced by india

Write a report on the security threats faced by india

In: Mechanical Engineering

can you answer those question as a field service engineer for job interview 1-Please describe in...

can you answer those question as a field service engineer for job interview

1-Please describe in detail your knowledge of electrical engineering?

2-Please describe in detail your knowledge of mechanical engineering?

3-Please describe in detail your knowledge of computer software?

4-What does customer service mean to you?

5-What interests you most about this position?

6-What are your career goals?

7-Why are you looking for another job?

8-What is your business travel tolerance?

9-What has been your business travel levels in your past opportunities?

In: Mechanical Engineering

Consider the vertical rear window of an automobile that has a thickness L= 9 mm and...

Consider the vertical rear window of an automobile that has a thickness L= 9 mm and height H=0.5 m with heating wires that create uniform volumetric heating. The window interior is exposed to ambient air at 10°C and the window exterior to air at -10°C which moves in parallel flow over the surface with a velocity of 20 m/s. The surface temperature of the window exterior is 12°C. Find the volumetric heating rate necessary to keep the window interior at 16°C. What is the convective heat flux for the interior and exterior of the window?

In: Mechanical Engineering

A white van is parked in the sun. The direct irradiance (Gdir) from the sun is...

A white van is parked in the sun. The direct irradiance (Gdir) from the sun is 1065 W/m2 with an incidence angle of 20o from perpendicular to the roof of the van (area 3 m x 1.8 m). The roof has an absorptivity of 0.9 to solar radiation and emissivity of 0.2 to the surroundings (which have an effective temperature of 25oC). A gentle breeze of 25oC air blows over the van, with a speed of 6 m/s along the length of the van roof (3 m).

Assuming the bottom side of the roof is well insulated, calculate:

a) The convective heat transfer coefficient for the top surface of the roof of the van, assuming it is an isothermal flat plate and using the properties of air at 25oC.

b) The irradiance and the total radiative energy absorbed by the roof (assume Kirchoff's law applies for diffuse radiative transfer between the surroundings and the roof of the van).

c) The temperature of the roof of the van and its radiosity.

d) A supplier offers to apply a reflective coating that reduces the absorptivity at solar wavelengths to 0.7 but reduces the emissivity at ambient conditions to 0.05. Would you recommend this as a solution to reduce heat transfer to the van? Why or why not?

In: Mechanical Engineering

It is noteworthy that during a holiday trip, the water is discharged from a high tank...

It is noteworthy that during a holiday trip, the water is discharged from a high tank with a 30 cm diameter plastic pipe into a stream in the valley, and the idea of generating power from this water comes to your mind. The bird flight from the reservoir stream is 100 m and the height difference between the free water surface and the stream in the tank is 75 m.
(a) Show the relationship between the water flow in the pipe and the power to be obtained for the power plant to be installed to obtain power from this source by drawing the flow-power graph.
(b) Calculate the required water flow to obtain the highest power.

In: Mechanical Engineering

              Engineering graphic. 1. A circle of 50 mm diameter is resting on HP on end...

              Engineering graphic.
1. A circle of 50 mm diameter is resting on HP on end A of it’s diameter AC
which is 30 degree inclined to HP and makes 45 degree inclination to VP. Draw its
projections

In: Mechanical Engineering

question : 1 While cores increase the cost of castings, they also provide a number of...

question : 1

While cores increase the cost of castings, they also provide a number of distinct advantages. The most significant is the ability to produce complex internal passages. They can also enable the production of difficult external features, such as undercuts, or allow the production of zero draft walls. Cores can reduce or eliminate additional machining, reduce the weight of a casting, and reduce or eliminate the need for multi-piece assembly. Answer the following questions about cores.

  1. The cores themselves must be produced, and generally have to be removed from core boxes or molds. What geometric limitations might this impose? How might these limitations be overcome?

  1. Cores must be positioned and supported within a mold. Discuss some of the limitations associated with core positioning and orientation. Consider the weight of a core, prevention of core fracture, minimization of core deflection, and possible buoyancy.
  1. Because cores are internal to the casting, adequate venting is necessary to eliminate or minimize porosity problems. Discuss possible features to aid in venting.

  1. How might core behavior vary with different materials being cast—steel versus aluminum, for example?

  1. Discuss several of the reasons cores may be made from a different material than the molding material used in the primary mold.

  1. Core removal is another design concern. Discuss how several different core making processes might perform in the area of removal. What are some ways to assist or facilitate core removal?

In: Mechanical Engineering