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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
How rack and pinion is used for indexing mechanism?
you need
a rack and pinion nut breaker to which you fix a pinion at the free end ie where nut is placed to be cracked. This is because you need to convert reciprocating motion of the rack and pinion mechanism built in the nut cracker into circular motion. Attach the nut cracker to the collect chuck shaft through the bore of the additional pinion you installed at the free end of the cracker. When you punch the nut cracker vide its handle once it moves the pinion one tooth on the rack. Thus you can rotate ( ie give angular motion to ) the fixed workpiece from one tooth or as many teeth as you like., depending on the pitch of the threads on the rack and pinion.
mazHur
What are the problems that can occur during handover and how can they be overcome?
Incorrect tools
Incorrect orders
Person commencing not competent, lack of experience or no knowledge of machinery
Poorly informed information about work already completed
the frontal area of a centrifugal compresor is more as compared to axial flow compressor for a given air flow. And for this reason axial compressors are being used in aircraft engines.
Catenary is the curve formed by the Turbine Rotors when they are placed on their respective Bearings.The level of each bearing and its housings are ear marked or indicated by the manufacturer of turbines.At the time of erection this is to be followed by laser alignment or by piano wire,water level etc
What is a list of the advantages and disadvantages of fluid power systems?
The advantages of fluid power
Fluid power systems provide many benefits to users including:
- Multiplication and variation of force-Linear or rotary force can be multiplied from a fraction of an ounce to several hundred tons of output.
- Easy, accurate control-You can start, stop, accelerate, decelerate, reverse or position large forces with great accuracy. Analog (infinitely variable) and digital (on/off) control are possible. Instantly reversible motion-within less than half a revolution-can be achieved.
- Multi-function control-A single hydraulic pump or air compressor can provide power and control for numerous machines or machine functions when combined with fluid power manifolds and valves.
- High horsepower, low weight ratio-Pneumatic components are compact and lightweight. You can hold a five horsepower hydraulic motor in the palm of your hand.
- Low speed torque-Unlike electric motors, air or hydraulic motors can produce large amounts of torque (twisting force) while operating at low speeds. Some hydraulic and air motors can even maintain torque at zero speed without overheating.
- Constant force or torque-This is a unique fluid power attribute.
- Safety in hazardous environments-Fluid power can be used in mines, chemical plants, near explosives and in paint applications because it is inherently spark-free and can tolerate high temperatures.
How are any waste materials and or products transferred stored and disposed of?
Many waste materials end up in landfills. This causes pollution and excessive littering in the environment. Harsh chemicals are often spilled into the ground as well.
What is the difference between Digital Scroll Compressor and Inverter scroll compressor?
In digital scroll compressors, the motor runs continuously at full speed, and the capacity of the compressor is adjusted by a digitally controlled mechanical unloader (slide bar) which adjusts the vertical positioning of the orbital scroll with respect to the fixed scroll thereby reducing its capacity.
In inverter scroll compressors, the relative positions of the scrolls does not change, but the speed of the motor is adjusted by a variable speed drive, which adjusts the capacity.
The inverter scroll compressor is more energy efficient at part load conditions than a comparable digital scroll compressor. The digital scroll compressor will more closely match a specified load, but is not as energy efficient as a comparable inverter driven compressor. Both types of compressors have associated built-in mechanisms to maintain compressor lubrication at low flow.
Why the teamwork is important in the engineering design?
Team work is very important because the teammate put their ideas in a project.
it will help a team leader or manager to do a perfessional project.
from
leo
Why is carnot cycle not suitable as an ideal cycle for all power producing cyclic devices?
The Carnot Cycle is a prime example of what is possible under the laws of physics however the cycle is impractical to build. The facts that its keeps stepping back and forth from isothermal to adibatic processes make it very hard to construct.
Why brayton cycle is not used in reciprocating engine?
The Brayton
Cycle originally was used as a reciprocating, not a turbine, engine and in fact was used to power the U.S.
Navy's first engine powered submarine.
The drawback to reciprocating Brayton
engines is that they operate on low pressure ratios (typically 3:1 for a recuperated cycle) and require a large volume flowrate
of air to make power. Turbines can turn at very high speed and can move large volumes of air in a fairly compact package. Reciprocating engines turn much slower and so, with a Brayton
cycle, they become fairly large.
Nevertheless, there are enough advantages that you will soon see reciprocating Brayton
engines back in commercial operation, particularly for sub-mW
electric power generators. Turbines have blade leakage and windage
losses that become significant at smaller sizes. Another very important consideration is that turbine
engines are expensive to build while reciprocating engine construction is universal and inexpensive. Maintaining reciprocating engines in remote areas only requires skills that are generally available from local mechanics while maintaining turbines requires specialized skill. Finally, although it may be much larger than a turbine counterpart, a reciprocating Brayton
electric generator can have the compressor, expander, and synchronous generator all on a single shaft and can thus avoid the expense, noise, and maintenance of a high speed gearbox.
Turbines will remain the preferred configuration for the majority of Brayton
engines, but reciprocating Brayton
engines have a place that is now becoming more appreciated.
Why is it called ansi 150 ansi 300 etc?
The number (e.g. 150) is the lb force the flange is rated to.
Why centrifugal pump is not called a positive displacement type of pump?
A positive displacement pump causes a fluid to move by trapping a fixed amount of it then forcing (displacing) that trapped volume into the discharge pipe. Centrifugal pumps impart pressure to the fluid, to cause a pressure differential and cause flow, but even if the outlet is sealed, the pump can continue to run because it hasn't trapped the fluid. When no flow is occurring, a centrifugal pump acts like a propeller spinning in the water. If flow is stopped on a line that a positive displacement pump is supplying flow to, the pump is forced to stop since the trapped fluid prevents it from moving any more fluid.
What are the phases of eutectoid steel?
Preeutectoid steel which appears in a temp. more than 723c and Proeutectoid steel which appears ina temp less than 723c
preeutectoid steel contains ferrite and austentie
proeutectoid steel contains ferrite and cementite
What is difference between monoblock pump and centrifugal pump?
A monoblock pump is a small pump that has no base plates, couplings, or guards, which keeps it small. A centrifugal pump is larger, with added features and impellers to give the pump hydraulic lift.
Can water jet cutters be used to cut limestone?
yes.. water jet cutters are the strongest cutters apart from lasers and diamond tipped blades... they can cut through any solid except for diamonds, and some hard gems...
What is the difference between mechanical fitter and Mechanical technician?
A couple quid an hour! :)
I was just wondering the same thing and hoped this question had an answer on here. I've just returned from a trade test with Amec for offshore work and there were test papers for mechanical fitters and technicians. it appears to be only offshore where they make a difference between the two. I served my apprenticeship as a mechy fitter, but my trade papers say technician.
I think fitters will be more involved with simple remove and replace jobs. "replace this valve/pump etc"
where as a technician will be more involved with diagnosis and repair/overhaul of mechanical equipment.
that's my take on it. but as often happens in shut downs and hook ups, we all end up doing the same bloody jobs as each other and, as I said at the top of the post, the techs get a bigger wedge at the end of the trip!
How is wool comparatively stronger than steel?
wool has many crimps so it can carry steel and it is elastic
How much quantity of water can deliver by a 5 hp pump in a hour?
Pumps and discharge
One HP Pumpset gives a discharge of about 2200 gallons per hour.
Discharge rates according to the size of pumpsets:
1 HP (1"X 1", 1.5" X 1.5") : 2000 - 3000 gph
1.5 HP (1.5" X 1", 2"X1.5") : 3000 - 4000 gph
2 HP (2"X2", 2.5" x 2", 3X3.5) : 5000 - 6000 gph
3 HP (2.5" X 2". 3" X 2.5") : 6000 - 7000 gph
5 HP (4" X 3". 3" x 2.5".2.5 X 2) : 1000 - 12000 gph.
While erecting a pump
1. Maximum suction head shall not exceed 7 meter (20 ft). Suction head is measured from water surface of source to pump level vertically.
2. Suction pipe shall be erected vertically, it shall never be allowed in a slanting position.
3. There shall not be any leak on the suction side.
4. Foot valve must rest atleast one metre above the water bed. If foot valve touches ground, it will suck dirt and sand, and pumping to avoid frictional loss.
5. Polythene pipes are preferable to avoid frictional loss.
6. Usually centrifugal pumps are used where suction is less than 7 m. A single stage pump is used where total head (suction head + delivery head) is not more than 40 ft (13 ms). Stage pump @ 1 stage for every 40 ft. may be used. Thus for 120 ft. total head, a three stage pump shall be used.
7. Where suction head is more than 20 ft. Ejecto pumps (jet pumps) shall be used. A jet pump will pump water from wells upto 100ft deep.
8. Single phase pumpsets are available upto 1.5 HP. Above 2 HP. only three phase pump sets are available. So small farmers having an area upto 3 acres may go for single phase pumpsets rather than 3 phase to avoid 3 phase electric connection which may not be readily available.
Commanding potential of pumpsets
1 HP upto 2 acres
2 HP upto 4.4 acres
3 HP upto 5 acres
Area and depth of irrigation
A 5 HP pumpset gives an approximate discharge of 11000 gph. If this pump is worked for 10 hours it gives a discharge of 110000 gallons of water approximately. If the area of the farm is 5 acreas the depth of water will be 110000/22000 which is 5 inches. (22000 gallons = 1 inch in 1 acre).
Calculation bits
1 cubic metre of water weights : 1 tonne or 1 MG
1 cubic metre per second : 1 cusec.
1 atm. at sea level : 10 metre column of water
1 HP : 75 kg m s-1, 746 watts
1 cm column of water of height 10 m exerts a pressure of 1 kg/cm2
MANOJ JADHAV
+919096273536
Is cold rolled mild steel magnetic?
Yes, all steels are magnetic. The difference is in the material being a "soft" or a "hard" magnetic material.
A cold rolled mild steel, such as 1018 steel, is considered a "soft" magnetic material.
I recommend reading "ASM Ready Reference: Electrical and Magnetic Properties of Metals" by Charles Moosbrugger and Fran Cverna for reference details and information. Particularly the brief section of Chapter 7 would be most helpful to you, with values in Chapter 8.
Measure external diameter. (A)
Measure internal diameter. (B)
Subtract B from A
What is the calibration curve of orifice meter?
The calibration curve for an orifice meter will depend on the size of the orifice, the size of the pipe and the pressure loss over the meter. Typical calibration curves have pressure (or head) loss on the vertical (y) axis and flow rate on the horizontal (x) axis.
Wherever there is stress there is strain.
In the example you noted, if heated bar expands freely without one end constained it changes its strain without stress; that strain is called eigenstrain.
If the same bar is held rigidly then the eigenstrain resisted and you get stress and strain. So stress cannot exist without strain; but strain can exist without stress if it is eigenstrain.
