A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines.
Mechanically, a fan can be any revolving vane, or vanes used for producing currents of air. Fans produce air flows with high volume and low pressure (although higher than ambient pressure), as opposed to compressors which produce high pressures at a comparatively low volume. A fan blade will often rotate when exposed to an air-fluid stream, and devices that take advantage of this, such as anemometers and wind turbines, often have designs similar to that of a fan.
Typical applications include climate control and personal thermal comfort (e.g., an electric table or floor fan), vehicle engine cooling systems (e.g., in front of a radiator), machinery cooling systems (e.g., inside computers and audio power amplifiers), ventilation, fume extraction, winnowing (e.g., separating chaff of cereal grains), removing dust (e.g. sucking as in a vacuum cleaner), drying (usually in combination with a heat source) and providing draft for a fire.
While fans are often used to cool people, they do not cool air (electric fans may warm it slightly due to the warming of their motors), but work by evaporative cooling of sweat and increased heat convection into the surrounding air, due to the airflow from the fans. Thus, fans may become ineffective at cooling the body if the surrounding air is near body temperature and contains high humidity. A fan blade is generally made of wood, plastic, or metal.
Fans have several applications in the industries. Some fans directly cool the machine and process, and may be indirectly used for cooling in the case of industrial heat exchangers.
These are critical machines and responsible for operating the entire plant, which may shut down without the proper fan. In mine and tunnel, it also used as safety equipment.
So I'm working on a thesis project at the moment designing an airship, and I've run into a bit of a stumbling point.
I'm wondering if it would be possible to have a propeller that works to produce propulsive power when it needs to fly, but when the craft is tethered could operate as an...
Homework Statement
Been at this question for some time an needing a double check to see if things are right.
A fan that consumes 20W of eletric power when operating is claimed to discharge air from a ventilaed room at a rate of 0.25 kg/s at a discharge velocity of 8 m/s. Determine if this...
Air or Water:
I'm looking for information on fan and propeller shapes (ducted and non-ducted) which might lead to more quiet if not more efficient shapes.
Noise is lost energy just as heat is lost energy in a mechanical system, right?
I have a thread which contains many bits of...
I am playing with a small personal fan and I noticed that when the blades are moving at some frequency that "lines up" with my monitor refresh rate frequency, they appear blurry and stationary, but with altered shapes. Not only that, but certain edges of the blades are colored blue, while the...
Say I have a commercial building that has a 24 inch diam. exhaust fan that is blowing approx 40 mph wind out of the building. I wonrder if I can make good use of this wind by mounting a 24-26 inch pipe that may be 6 to 10 ft long on the outside of the building. I imagine cutting out sections in...
Hi guys
I suddenly think of a question. In my home, there's a standing fan which is old so I cannot see the nominal power on the label. With a ohm meter, can I identify the power of the fan? The meter can measure resistance R, potential U and current I of an AC power supply.
(This thread...
Hi guys
I suddenly think of a question. In my home, there's a standing fan which is old so I cannot see the nominal power on the label. With a ohm meter, can I identify the power of the fan? The meter can measure resistance R, potential U and current I of an AC power supply.
Hai
I am using a double shroud fan wheel for our application. what will be happened, if i use the same dimensions fan wheel with single shroud ?. can u clariffy for the same in the following points.
1. Discharge
2. Total Head or static head or Dynamic head
3. Power
With regards...
hey guys,
I'm new here but i was a bit stuck on thinking about how air flow is effected by a fan. it's probably a really simple question, but it's got my cobwebbed brain a bit stumped!
my question is in two parts:
1. how does air flow relate to the design of a fan? ie, an answer with...
----bernoulli principle in fan----
when a fan is started, why is there more air flow at the bottom of the fan and not at the upper region of fan...:confused:
>>Also explain if bernoulli principle is involved in this
thx an regards
arun
I am trying to control a 110V fan with a low voltage thermostat. I am pretty new to electrical theory... I would like a basic description of what I need and how to properly wire it. Thanks!
can anybody help me to find the answer of this question?
a fan ( or a propellor) rotates sidewise, but the air goes making a perpendicular with the axis of its motion.. I know that there is vector involved in this, but how does it work?
(I think I've actually asked this before...):blushing:
I have a standard 3 speed reversbile ceiling fan. The reverse switch of course changes it from blowing air up to blowing air down.
What is the benefit of reversing the fan?
Most people seem to think that it constitutes a difference...
"Bifurcated fan"
What does the term "Bifurcated fan" actually mean?
Please provide a link to some examples and or illustrations which clarify the term.
The images and text I've seen using Google image search
"Bifurcated fan" have shown.......
1. Axial fan with centered engine pod; front...
When I heard Condi say this on Meet the Press
http://www.msnbc.msn.com/id/14215314/page/2/
I kept thinking how I had just heard this recently for the first time. Now where did I hear that... hmmm... oh yes, I remember, it comes from Al Gore and his "Inconvenient Truth" ! :smile: :smile...
I forget, which direction do you set ceiling fans to spin (clockwise or counter looking from below) in teh summer? It's about 10,000 degrees and I am taking every measure not to die.
I was going to post this in the World Cup forum, but there isn't an appropriate thread. It is more of general interest than the WC, and applies to anyone traveling to some place unfamiliar.
Soccer Fan Spends Six Hours Hunting for Hotel :rolleyes:
Reuters
Know where you are, and know where...
I was reading a discussion about heaters on another forum ages ago, one person claimed that there is a large difference in cost when running a thermostatically controlled oil filled radiator than an electric fan heater. Another person told him to contact the Institute of Physics and inform them...
Hey everyone i was just wondering, for future reference, which type of fan generally yields the greatest output velocity/volumetric flowrate and a relatively low pressure drop (ie like +/- 10kpa sort of thing), assuming axial speed is the same for each of the general types of fans. This would be...
Is anyone else a fan of the bow and arrow? For the past two months I've been archery-happy, spending most of my free time target shooting in the back yard, making arrows, fixing arrows, making bowstrings, googling the subject and shopping for archery stuff at the weekend swap meets here...
Hi, :approve:
I want to do porject for Turbo Fan, so I need some information about it. If you could help me, please don't shame and gimme me this information to help me.
Thanks,:smile:
I appreciate it:biggrin:
I've become particulary fond of these, 3x3 boxes with 3x3 boxes in each and you must have 1-9 vertical, horizontal and in each 3x3 box. I'm sure most have seen it before. The link below provides a program for it. I average 12 minutes on hard puzzles.
http://www.sudoku.com/
I need help in identifying this electric fan motor and its parts for a project documentation. Please see the pictures.
http://img.photobucket.com/albums/v196/malinis/DSC00093.jpg
http://img.photobucket.com/albums/v196/malinis/DSC00094.jpg
I would like to ask:
- What specific kind...
Not sure if this is in the right topic, but does anyone know the difference between a fan and a pump? I'm working on something where I need to distinguish a fan from a pump. I need to do so without limiting the pump to any specific type. Basically I need to allow for a piston & cylinder type...
First, I'm not an engineer, so, please excuse my lay terminology. Nonetheless, I thank you for any thoughts you can offer me, as I certainly need some help here.
I'm working on a project where I need to spin a 4"-6" fan blade, enough to create about 250 (more is even better) cfm of airflow ...
I often hear people suggest switching the direction of a ceiling fan from 'blow' to 'suck' or the reverse, thinking that one will draw cool air in better.
My intuition tells me that:
- a ceiling fan blows air in a doughnut patterrn, where air flows either up in the centre or down in the...
It is really hot, and humid here. I have my fan running almost constantly. Ever since I was a kid (well I am still kind of young) I have talked into my fan and got a kick out of hearing my distored alien voice. I was wondering what is the physics behind this distorsion? I was thinking that...
An electric fan is running on HIGH. After fan has been running of 13.2 minutes, the LOW button is pushed. The fan slows down to 98 rad/sec in 1.83 seconds. The blades of the fan have a radius of 0.62 meters and their deceleration rate is 42.3 rad/sec2.
What was the initial angular speed of...
I've never been a fan of Eurovision, but I usually end up watching it for whatever reason (being outvoted by girls, usually). But last year, two things about Eurovision dawned on me.
Firstly, the voting is entirely political. Now I'm not being a sore loser here, and in fact, I was positively...
basically i want to know for a fan whether the air flow created is more reliant on speed or torque, if there's some sort of equation out there that'd be helpful too!
Thanks.
I list the question one by one. I hope this is a good arrangment.
1.The blades of a fan is rotating in an anti-clockwise direction. Its motion is frozen with a strobe frquency of 1000 Hz without a change in appearance. Which of the following is not a possible rate at which the wheel is...
Now this guy here is a true and loyal fan of his team : http://www.mirror.co.uk/news/24by7panews/tm_objectid=15165311&method=full&siteid=50143&headline=welsh-rugby-fan-cuts-off-testicles-after-win-name_page.html
WARNING : Possibly scary stuff below...
What is the most you'd do to show...
Hey guys;
When I was really young, I saw on a TV a guy who had a gas-powered fan mounted on to his back, and he could ontrol the throttle with somethin in his hand. He got on rollerblades and could zoom around a track at pretty decent speeds (30+ mph). There was no stopping mechanism...
Why is the airflow of a fan (a regular house fan for instance) stronger on one side than it is the other? I think it has something to do with the fact that the airflow is a vortex, but I don't understand how this creates uneven airflow.
Thanks
I am doing an investigation into the air flow from a fan in my physics class. I need to know why the reason why air flows in a vortex shape from the fan (in physics terms), and what equations I can investigate (anything, e.g thrust etc).
Also, I believe the airflow from a fan can be...
hey, i am a year 11 student, we have an assignment where we must build a fan (non electric) that will spin once wind from a wind tunnel in blown onto it...Now i know this may sound rather simple, and it probably is...but i am just looking for some guidlines on how to make a fan that will WORK...
Hey people i have recently purchased "up and around the bend, the definitive hanoi rocks collection"
I think they where absolutely brilliant and the most underated band in history, their material is so unique, considering they are an 80's band.
Has anyone else heard of these guys? If so...
I have to say, there are few people from whom I find inspiration, but Larry Walters is definitely on the list.
http://www.markbarry.com/amazing/lawnchairman.html
If anyone knows of any other under-dogs who fulfilled their life-long dreams (despite the odds), let me know who these people...
i just woke up and i looked at my electric fan...and noticed a lot of dust had accumulated on the fan...anyone haf any idea y? shouldn't the wind generated from the fan blow the dust away?