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 the function of back pressure valve in Boiler feed pump?
The function of back pressure valve is to prevent back flow to the pump in case there is an obstruction on downstream side of valve.
What is the runway speed of a hydraulic turbine?
Runway speed is the speed at full opening of guide vanes at nominal head and no load on Generator
What happens in a grit chamber?
in a grit chamber mixing of grit takes place.after grit mixing only organic matter remains
What is non concurrent force system?
In a concurrent force system, all forces pass through a common point. In the previous case involving the application of two forces to a body, it was necessary for them to be colinear, opposite in direction, and equal in magnitude for the body to be in equilibrium. If three forces are applied to a body, as shown in the figure, they must pass through a common point (O), or else the condition, SMo= 0, will not be satisfied and the body will rotate because of unbalanced moment. Moreover, the magnitudes of the forces must be such that the force equilibrium equations,
SFx= 0, SFy= 0, are satisfied.
Why coefficient of performance of absorption cycle is less than compression cycle?
In case of vapour compression cycle (VCC) the COP is given by (desired effect / work input). in the other words it can be defines as what we want and what we are paying for that... so in VCC the paying amount is very less as due to low temperature difference that why its value is more than 1. but in case of vapour absorption system the COP is given by (heat taken by evaporator/ heat given to generator). the heat input taken by evaporator is less as compared to heat given to generator.. that why its COP is less than 1......
What does P and H stand for on large mechanical equipment?
Pawling and Harnischfeger
Industrial artisans Alonzo Pawling and Henry Harnischfeger started the manufacturing business that would evolve into P&H Mining Equipment in 1884 in http://wiki.answers.com/en/Milwaukee, http://wiki.answers.com/en/WisconsinUSA.
How are overhead traveling cranes powered?
While overhead traveling cranes are sometimes operated manually, they are usually powered by electricity
What do you have to do to change a motor from carbarator to fuel injected?
An understanding of fuels systems for engines. The correct and complete injection system for the engine. A well equipped workshop and a great deal of engineering skill.
This link explains it very well.
http://www.physlink.com/education/AskExperts/ae221.cfm
How much does Spaceship Earth weigh?
It weighs sixteen million pounds, is 180 feet tall, and takes up two million cubic feet of space.
How can you open a Samsonite Travel Sentry threedigit lock if you forgot the code?
Funny thing. I actually had the same Samsonite Sentry lock for years stuck in the unlocked position because i DID forget the code too. Just recently figured out how to unlock the sucker. Here's what you do. This works for whether it's stuck in the open or locked position but you forgot the code.
1) Make sure the lever is in the "closed" position. Even if it's not closed, line it up with the opening
2) Push down on the lever and keep it held down throughout the rest of the directions
3) Starting from the bottom dial, slowly turn it through each number. Each normal number should have the same resistance as you're turning it UNTIL you get to the right number. When you get the right number suddenly you should feel it easily pop into place like it wants to be there.
4) Repeat with the next dial up and then the last dial at the top.
5) When you feel the last dial just "pop" into place like the other two, the lever should suddenly be free to recess into the lock OR be unlocked and able to twist around freely.
6) now remember this combo or to reset the lock to a code you can remember.
Honestly, it seems way too easy to unlock this thing and your luggage suddenly doesn't feel THAT safe anymore does it?
How do you turn a bar on a center lathe?
The basics procedure used for turning a bushing on lathe are:
- Material is inserted and tightened into the chuck so it protrudes about 10mm over the actual length of the final bushing length
- If the material is not hollow bar, a drill is inserted into the tail stock then the material is drilled to enable the a boring bar to fit the hole
- A roughing tool is inserted into the tool post then the face of the workpiece is machined smooth and the outside diameter to about 0.5mm oversize
- A roughing boring bar is inserted into the tool post and the inside diameter is machined to roughly 0.5mm undersize
- A finishing tool is then inserted into the tool post then first the face and then the outside diameter of the workpiece is machined to the required size
- At this point a finishing boring bar is inserted into the tool post and the inside diameter is machined to the required size
- Chamfer tools are then used to chamfer both outside and inside edges at the face
- The parting tool is inserted into the tool post then the bushing is parted off about 0.5mm to 1mm longer than specified.
- The remainder of the material is removed from the chuck then the parted bushing is inserted and tightened with the unfinished side protruding about 5mm to 10 mm.
- A finishing tool is inserted into the tool post then the face is machined to the required size
- Chamfer tools are then used to chamfer both outside and inside edges at the face
The above method is just a basic explanation of how the operation is achieved. Operating a lathe without proper training is not recommended and could lead to serious injury!
How do you build a paper boat?
Below is a link that features a number of tutorials on how to make a variety of paper boats .
What formula do I use to set the angle on my lathe's tool post to cut a taper from a drawing?
A = Large end diameter of the taper
B = Small end diameter of the taper
L = Direct distance between A and B
Formula: A \ B \ L \ 2 then Invert Tangent = The degrees you set your tool post at.
Why is Pump discharge line size smaller than suction line size?
An increase in any pipe diameter will lower the flow velocity, and therefore reduce head loss due to friction, but it is not immediately obvious to me why pump manufacturers provide a discharge side of smaller diameter than the suction side. I don't think it has anything to do with cavitation, maybe it is just to ensure that fluid flows easily away from the pump, since it will be travelling at a higher velocity in the discharge line than entering the pump on the suction side. Maybe the NPSHR values are derived from the difference in pipe diamters across the pump by the manufacturers, such that cavitation does become an (indirect) issue. Maybe somebody else can answer this one. The suction side of the pump normally has only atmospheric pressure of approximately 1 bar available to propel the oil into the pump. Using a larger suction diameter reduces friction loss, and keeps the fluid as close to atmospheric pressure as possible. Fluids will boil at a lower temperature when subjected to vacuum, and hydrauic systems already have a high temperature due to friction losses elsewhere in the circuit. If the suction side is allowed to develop too much vacuum, the lowered boiling point will be exceeded, and cavitation that is destructive to the pump will be induced. The problem can be alleviated by pressurising or elevating the oil tank to maintain a positive pressure at the pump inlet.
Compositional difference between PNG and CNG?
Any of these relevant? CNG can mean: * Compressed natural gas, e.g., CNG vehicles * Cypriot National Guard, the combined arms force of the Republic of Cyprus * Chinese National Geography, magazine published in China * Comfort Noise Generator used in Speech Codecs to insert artificial noise during silent intervals of speech. * Conseil National de Gouvernement, provisional government of Haiti from 1986 to 1988 * Cyclic nucleotide-gated ion channel an ion channel gated by cyclic nuclotide like cAMP * Certified Naturally Grown a certification program for small-scale, direct-market organic farmers * Cryptography API: Next Generation, the pluggable Windows Cryptography API introduced in Windows Vista
PNG may stand for: * Papua New Guinea, a country in Oceania, located in the southwestern Pacific Ocean * Partidul Noua Generaţie, former name of a Romanian political party * Persona non grata, a term used in diplomacy which literally means "an unwelcome person" * Portable Network Graphics, a bitmap image format that employs lossless data compression (typically uses the "png" file-extension) * Procter & Gamble, an American corporation manufacturing personal goods
Is Hydraulics More Effective Then Pneumatics?
My thoughts go like this...(from watching 'Scrapheap Challenge"0 plus a little basic knowledge of physics.
1/ Pneumatics involve the movement of pistons and what not via the medium of compressed air or air under pressure.
2/ Hydraulics involve the movement of pistons and what not via the medium of compressed fluids or fluid under pressure.
3/ Fluid is denser than gas (compressed air).
I believe hydraulics can handle far heavier loads than pneumatics.
Pneumatics would appear to use a lighter more flexible medium than hydraulics.
In answer to your question, I believe hydraulics would be far more effective at manipulating heavy loads versus pneumatics.
However, pneumatics would be a more flexible system than hydraulics.
Hows that?
Can a globe valve be uses as a blowdown valve?
HECK NO READ the ASME code or the NBBI Also read up on valves and what they are designed to do.
A "Globe" valve is used for THROTTLING and severely restricts flow
Personally I like using a GATE valve in combination with a ball valve for Blow down applications
