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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
It's a matter of the steam cycle, the condenser in a condensing power plant creates a vacuum, or low pressure zone for the steam to flow into. A compressor would need to compress this steam 650 times plus generate enough force to force it back into the boiler, this would require a lot of energy to do. It is much simpler and much more cost effective (energy wise), to condense the steam and exhaust the excess heat to the cooling tower. The condensed water can then be pumped back to the boiler in stages to repeat the cycle. In these stages the water is de-aerated, treated and heated back to the boiler's temperature to prevent thermal shock in the boiler. In short condensing the steam is easier, safer and cheaper than trying to mechanically compress it.
**By the way, there are vacuum pumps called "hoggers" or steam powered ejectors, and injectors which could do just what you suggest, but use exorbitant amounts of energy to do so. These are typically used in conjunction with condensers to eject non-condensible gasses from condensers.
Why would the landing gear on a jet airliner come out during ascent 10 minutes after takeoff?
When you refer to "come out", I assume you mean the gear came out of the wheel well. The correct term is Extend.
Most landing gears have an Actuator that extends and retracts it into the DOWN and UP (or Retracted) positions. Once it is in that position, the drag brace and lock links will usually hold it in place. Some a/c such as DC10 Main L/G, the gear rests on the door and the door is held closed by a lock.
I am familiar with failures of the retract Actuator on a DC10 Main L/G, that causes the gear to fall out of the wheel well just before it locks. This would have to happen before the gear locks in the UP position.
For it to fail 10 minutes after retraction, that means there was a failure of the door latch to remain locked. Again, for the DC10 Main L/G, the door latch is operated by a hydraulic latching mechanism. This would probably mean that the door latch and roller was not rigged properly OR the door itself was out of rig.
The Boeing 727 Nose L/G has the locking mechanism in the drag brace. The drag brace locks in both the UP and DOWN position. The locking mechanism is a set of pawls that lock the "knee" of the brace where it bends. If the locking pawls are worn, I believe it will not lock and it might release. Also, water will get into the joint and freeze the grease, preventing the operation of the mechanism.
Also, there is a possibility that the gear did not actually extend; only the GEAR UNSAFE light came on because of a failure of the sensor. This would be a false alarm but the crew would have taken action to correct.
Also an aircraft will burn more fuel with the gear extended. So it is most likely that the a/c will not have enough fuel to reach its destination. Thus the aircraft will return to the airport or divert to another airport.
It is not good to have the gear suddenly fall out of the wheel well. There are speed limitation for retraction and extension of the gear. Many a/c is allowed to fly faster with the gear down than during the retraction/extension phase of flight. If the a/c is flying at cruise speed, severe structural damage could result.
AnswerBest guess mentioned above would be either an unsafe gear light or a gear door open warning light. Both would normally call for recycling the gear. Another possibility not mentioned above would be overheated brakes that would call for extending the gear for a short period of time to cool the brakes. This procedure would probably have happened sooner than 10 minutes after takeoff.Conclusion: The scenerio that I think happened was that the pilot commanded the gear to be retracted on take-off. The gear indication was UNSAFE, meaning the light in the cockpit said it was not fully retracted. The crew completed their takeoff and checked their systems and then announced to the Passengers that the gear was unsafe. They then extended the gear(either before or after the announcement) and returned to the airport.
A steamboat uses a steam engine similar to those on a steam locomotive. An external wood or coal fire heats water in a boiler, and the pressure of its expansion into steam is used to turn a shaft that is connected to paddlewheels, or to a propeller blade.
Steamboats were the first alternative to sailing vessels, and replaced them as the major form of marine vessels. Modern steam turbines (invented in 1884) continue to be used for the generation of electricity worldwide.
What is the basic salary for mechatronic engineer?
The average pay for a "starting" mechanical engineer is about 69,000 and the starting pay for a "starting" electrical engineer is about 75,000 according to resources. (it is recommended you check for your area specifics) and since a Mechatronic engineer incorporates aspects of both of those fields one can probably expect pay within the 69-75,000 range.
you make it very hot and then very cold and if you better not be using this to rob a bank or some thin >:(
What is the meaning of general drill bit angle?
It is the angle between the cutting edges.It is usually 118 degrees
How do people enter and exit the submarine?
from the entrance :P
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Through hatches designed to withstand the pressure of the sea water when submerged.
A form of three-dimensional projection in which all of the principal planes are drawn parallel to corresponding established axes and at true dimensions; horizontals usually are drawn at 30° from the normal horizontal axes; verticals remain parallel to the normal vertical axis.
What is a wet start in turbine engines?
Normally when starting a turbine engine, the starter is used to get the turbine up to operational speeds, then fuel is pumped in with the ignition active.
A "wet start" is a start where the engine is being started with a quantity of fuel already pooled in the engine (perhaps the result of a previous failed start) or the pilot delays ignition beyond what is normal and allows fuel to pool in the engine before ignition. Wet starts can result in a fire plume or a loud bang, and may damage the engine. The most dramatic damage will be to the compresser turbine blades due to pressure and heat failure.
Why petrol engine not uses compression ignition?
Most gasoline engines are 8:1 - 10:1 compression, while a diesel engine requires closer to 18:1 - 20:1 to achieve the temperature required to ignite the fuel. Simply put an electronic ignition system is less complicated and more cost effective to mass produce. Especially taking into account the emissions requirements for todays "clean" diesels.
Gasoline is not ignited using compression ignition for two reasons. First of all, an electronic ignition is simpler and does not require heaver engine parts to increase compression. Secondly gasoline has a much lower flash point than diesel which makes it more volatile and dangerous. As a result, if you compress then ignite it the fuel will burn at a hotter and less controllable rate. If gasoline burns at too hot a temperature it forms Nox gas - "Oxides of Nitrogen" which is a major contributing factor to ozone damage and the greenhouse effect.
What is difference between mill and mill-drill?
Today many manufactures are combining machines, a mill/drill is one of these. Its a combination of a drill and a mill, a mill removes stock from material (usually metal, but not limited just to metal, it depends on your application), you use fluted cutters such-as end mills. the drill aspect of the machine is just that it drills holes, With the proper speed for the right size drill.
Not just "today". The milling-machine was invented in the 19C!
A milling machine will drill as well as it can mill, with the advantage of co-ordinate location; but "mill-drill" is a rather contrived name for a class of light machine-tool made primarily for hobby workshops. It occupies a sort of mid-way position between milling-machine and drilling-machine - the latter cannot and must not be used as a mill.
Typically the mill-drill has a cylindrical column as on a bench-drill, to support a head moveable vertically above a fixed-level (2-axis only) table: an arrangement which is not only cheaper to make and sell but not ever so rigid and plays havoc with your centring when you have to raise or lower the head to accommodate different drill lengths for the same work!
Whats the difference between a B18A and B18B Honda engine?
the diffence is the intake manifold and exhaust manifolds are slitly bigger
How do you re-season cast iron pans?
In order to reseason a cast iron pan, one will first need to wash the pan with soapy water using a nylon brush. Next, wipe a coat of vegetable oil on the pan and bake the pan for an hour at 350 degrees Fahrenheit.
What SI units should be used for flow per area - ie to convert gpm per ft2 to SI units?
If your flow is in Volume/Time, e.g. m3/s, and it's given per area, e.g. m2, you come up with the flow speed. An appopiate unit would be m/s
Example:
If your flow is 6 cubic meters per second, and this is given for 2 square meters, the flow has a speed of 3 meters per second.
Now the conversion to SI:
1 gpm = 6.30902e-5 m3/s
1 ft2 = 0.092903 m2
So 1 gpm per ft2 would give a flow speed of 6.79098e-4 m/s (0.68 millimeter per second)
If you don't have a volumetric flow, use the density of the material to convert it.
It is probable that tires were invented soon after wheels because the people who invented wheels soon found out it was a good idea to have tires on them which could be replaced when they wore out.
Well before pneumatic tires were invented, tires made of wood or iron were fitted to stone, wooden or metal wheels to make them last longer. If you don't have a separate tire, the whole wheel has to be replaced when its outside edges get chipped and worn away.
If this question is asking about pneumatic tires then search for questions and answers about pneumatic tires, not just "tires".
Is there a dictionary or list of rotary tool bits and what they are used for?
Sure. Lists of bits and rotary tools can be found in lots of places. The problem is that they are usually grouped by tool or machine. There are a ton of things you can chuck into a drill, like drill bits, wire wheels, abrasive stones, sanding drums, rotary files polishing attachments and the like. If you pick a mill, there are lots of things you can chuck in that, too. Same with a "Dremel" rotary tool. There are a number of hand held machines that take a bit or tool of some kind. And there are bench mounted and free standing machines that take different tools and bits, too. Think about what is in a wood shop, a machine shop, a plant that supplies decorative and architectural stone or at your local dentist or in your local hospital. Are you planning on including post hole drilling rigs and the lines of large industrial machines? Well drilling rigs, too? There are rotary tools for wood, metal, stone, ceramic and other things, and the tools vary a bit from one material to another. Try to list a few types tools that use a rotating bit, cutter head or the like. Then look up that tool or machine and see what's offered. As mentioned, the tools and bits are usually grouped with the machine into which they're fitted for use.
How accurate were the weapons of the American Revolution?
The principle small arm weapon of the British side was the Land Pattern Musket, better known by the nickname "Brown Bess". It was a muzzle loading smoothbore musket of .75 caliber. It had a quoted maximum effective range of about 175 yards although it was only truly effective out to about 75 to 100 yards. In well trained hands it could fire about 3-4 rounds per minute.
The Patriots used a variety of weapons including the Brown Bess, the French Charleville musket, and various hunting rifles. The Charleville musket had similar performance to the Brown Bess but fired a slightly smaller .69 caliber bullet. Many militia and irregular Patriot units were outfitted with civilian hunting rifles. Rifles had a longer range than the muskets, out to about 300 + yards, but took about two to three times longer to reload.
The main drawback to the rifle however is that a bayonet could not be attached to it. In a day when even the best firearm could only get off about 4 shots in a minute, a bayonet was a primary weapon.
What are the of classifications of reciprocating internal combustion engines?
classification of the reciprocating Internal combustion engine. according to t he cycle of operation.
1 two stroke
2 four stroke
according to the number of cylinders.
1 single cylinder.
2 multi cylinder.
according to the type of fuel
1 petrol engine
2 diesel engine
3 gas engine
according to the arrangement of the cylinder
1 horizontal engine
2 vertical engine
3 V engine
4 radial engine
5 W engine
according the the speed of the engine
1 low speed engine
2 medium speed engine
3 high speed engine
according to method of ignition
1 spark ignition engine
2 compression ignition engine
according to the method of cooling
1 air cooled engine
2 water cooled engine
according to valve arrangement
1 overhead valve engine
2 T head valve engine
3 L head valve engine
4 F head valve engine
according to the cycle of combution
1 otto cycle engine
2 diesel cycle engine
3 dual cycle engine
What are Examples of ipod closed loop system?
Consider it a kiosk as such. You will not be able to be "kicked out to the web", it is like a website without outside links. You can interact with the iPad through touch, but all links remain with the site.
