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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
What is the definition or description of fouling factor in chiller?
Impurities in the chilled water system eventually deposit on evaporator tube surfaces, impeding heat transfer. Cataloged performance data includes a "fouling factor" that accounts forthis effect to more closely predict actual chiller performance. Research conducted by theAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)reveals that the negative effect of fouling on the long-term performance of closed-loop chilled water systems is usually less than 0.00025 h·ft²·F/Btu. ARI Standard 550/ 590-1998 reduces the fouling-factor allowance from that value to the 0.00010h·ft²·F/Btu suggested by the study results.
Its Effect... Assessing a smaller fouling factor lets specifying engineers, owners, and manufacturers alike take credit for seemingly better heat transfer. With cataloged performance that more closely matches actual operation, specifying engineers can select chillers with greater precision-and owners purchase no more cooling capacity than they actually need. [The revised evaporator fouling factor has little effect on full-load efficiency, i.e. roughly 2 percent. As noted later,full-load efficiency remains an important criterion in many applications.-Editor]
How does a Bollinger engine work?
The engine is a 2 stroke 'semi' diesel. Inlet and exhaust are as per 'normal' two stroke diesel but the injected fuel is not ignited by compression alone as in a normal diesel. Instead a 'hot bulb' on the cylinder head is heated with a blow-lamp before starting and heat from this, transferred to a tube in the combustion chamber which ignites the fuel to start the engine. Once running the engine itself maintains the temperature. Often called a Hot Bulb Engine.
What is thermal efficiency of petrol engine?
The maximum Thermal Efficiency of Petrol Engine or Gasoline Engine or Otto Cycle Engine is about 25-30%.
AutoCAD is a Computer Aided Drafting program produced by Autodesk. Most people use it for slang like EX... "grab me a coke"...when really you want any soda....not specifically a Coca-Cola. Shows how much that program dominates the 2d CAD world
U.S. Submarines can dive 800-plus feet. (Official depth; however, can dive deeper. The US Navy itself acknowledges that most of it's attack submarines can operate down to at least 985 feet, and many to over 1400 feet.
What are the functions of milling machine?
A milling machine is a tool found primarily in the metalworking industry. In general, these machines are used to shape solid products by eliminating excess material in order to form a finished product. Milling machines can be used for a variety of complicated cutting operations - from slot cutting, threading, and rabbeting to routing, planing, and drilling. They are also used in diesinking, which involves shaping a steel block so that it can be used for various functions, such as molding plastics or coining.
What kind of material is used to make a tower crane?
carbon steel and some of it has to be heat treated there is only a select few of tower crane manufactures that has the stamps to build them
How a lathe machine is specified?
A lathe machine is specified by-
1.The maximum diameter of the workpiece that can be operated on the machine.
2.The distance between the headstock and the tail-stock of the machine.
3.The length of bed of the machine.
Do faulty thermostsats cause heater pipes to burst?
the velocity of the metals and the engine is going to be in his bad behavior.
Tumbled marble is real marble (or travertine) that is treated inside a tumbler for several hours to make it achieve that particular "worn-down" look.Type your answer here...
What cockpit control does a pilot use to control altitude?
Aircraft have two controls that are used together to control altitude.
- The elevator is used to increase the nose up pitch of the aircraft and it starts to climb
- The throttle must then be increased so the air craft will continue at the speed needed to climb
The throttle can be used only in some aircraft but it is not a real stable usable thing, the elevator must be used to stabilise the aircraft
To descend oer maintain altitude the same controls are used together.
Why did you stop using steamboats?
Because modern power plants can be built smaller, more efficient and quicker to bring online.
How much work is required to pull a sled 5 meters if you use 60n of force?
Work = (Force) x (Distance) = 60 x 5= 300 Newton Meters = 300 Joules
What is excess weaving in welding?
excessive We were taught 2-1/2 times the width of the electrode was maximum. ie: 5/16" width weld bead for 1/8" electrode.
Are there drills that drill square holes?
Yes, they are generally based on Reuleaux triangle shape, which is mounted eccentrically so points on its contour track a square shape when rotated.
Another way to "drill" a square hole is with a mortising bit. A mortising bit is composed of a regular round drill bit inscribed within a hollowed square chisel. Most of the material is removed by the drill bit while the corners are squared-off by the chisel.
Examples of alloy and their uses?
Brass and bronze are both alloys used for a wide variety of materials, especially in environments such as salt water that readily corrode most kinds of steel. Jeweler's gold is usually an alloy, unless marked "24 karat." Electrum is a silver-gold alloy that was used for coinage in ancient Greece and/or Asia Minor.
Why there is spark plug in petrol engine and not in diesel engine?
Because a diesel engine doesn't need spark to ignite the fuel. Diesels are very high compression engines, and the high compression makes enough heat to ignite the fuel. To prevent the fuel from igniting prematurely, it is injected only after the valves have closed and the piston is near the top of the compression stroke. Once the fuel is injected, the heat from the compression ignites it instantly.
What happen if you use hydraulic oil iso vg 46 instead of hydraulic oil iso vg 32?
i made this mistake on an hydraulic breaker pack,no damage was caused to the pump or breaker.however the operation of the equipment was sluggish until the machine really warmed up.presumably because the 46 oil is" thicker" than the iso 32
Why there are not pneumatic engines above 100kw?
pneumatic system use air and air has its limitation of use mainly due to its high compressibility as gas.high power applications may compress air to such an extent leading to destruction of the system.whereas hydraulics also have compressibility which is at an unnoticed level even at high pressure.
I meant motors or generators that run on air released from a reservoir of compressed air.
