Fan Definition and 338 Threads

I'm currently building a device that will blow a ping pong ball vertically up a tube but don't know what fan I am going to need. Each fan gives a CFM flow rate but the problem is that I don't know how to calculate the required fan CFM i'll need in order to push the ball vertically. In other...

I make industrial fans of which use impellers that can reach up to 80 m/s tip speed, i also learned that it shouldn't be tip speed but tip acceleration because the impeller is constantly changing direction it should be 80 m/s^2. So to calculate the force should i use force = Ma or m x...

Is it possible to connect solar panels to a mini hand held fan and making it run on both rechargeable batteries and solar panels? I'm sorry if it's vague. i need to make a hand held fan that runs automatically on solar panels (when there's sun) and on its rechargeable batteries (when there's no...

[SIZE="3"]Hi every body.. Say you trapped the drag tube before a fan, what would happen then? Will the Amber decrease? Will the motor be heated ? Why? Please I need reasonable replies ..

does anyone know how i can fix this? it's really annoying and i don't want to have to bring it in seeing as it sounds like the big external fan

Do you believe in "fan death"? Basically, I stationary fan left on in a sealed room could cause death by either suffocation or hypothermia. I know several researchers in Korea and in California have came out to say that it is all a hoax, but does anyone here know whether it is possible to...

Hi, How do I calculate the fan power (kW) and efficiency, given the flow rate, static/total pressure across the fan surface? Do I need more data? Thnx in advance.

Hi everyone, My computer fan keeps turning on fast, and then turning off (I think it's the fan, I'm not sure). The computer didn't seem to do that before. I was wondering if this is a bad sign (overheating?), and what should I check? Ed.

Hi guys, great forum you have here... basically, a couple of years ago, I've gotten involved in the hobby of watercooling computers by adding a radiator, pump and waterblocks on the cpus and other heat sources. well, as I've been researching builds by other folks, i notice that some...

Hi, I have been toying with the idea of producing electricity from the cross winds that build up in my house. Basically when I leave a window open one one side of my flat and open a window on the other the wind blows through the house very strong. I want to place a wind generator on one...

Here's a problem my professor assigned and expects us to know, yet he hasn't covered any of this material. We just started talking about angular velocity, acceleartion, etc. I understand that we are supposed to gather the relationships between these things by looking at the equations, but I...

Thanks to all who posted. The fan was built by Universal Hovercraft it's purpose built for a small hovercraft designed for kids to ride on. The fan is driven by a 5hp petrol motor which has a top rpm of 3000 rpm. I doubt the engine will get to this rpm with the fan attached but at 3000rpm the...

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. a) What was the initial angular speed of...

I'm trying to see how fast a fan that produces "x" cfm can move an object that weighs 150 lbs with a cof of 0.04. How would I set up an equation to find this? Thanks

Homework Statement a fan is attached to a sled blowing air to the right at a sail the sled is on ice and friction is neglected and the air around the sled is still except the air moved by the fan. will the sled move is so to the right or left. Homework Equations The...

I just bought this squirrel cage fan off ebay. My idea is to use it for a fume hood. According to seller it runs very well; I will clean, oil, and throw a coat of a paint on it. Got it for 20 bucks. The motor is completely separated from the cage as I wanted. However, it gives no CMF? It is a...

I'm looking for an on-line paper/article/pdf about ducted fans; "Interrupted air flow at fan inlet (subsonic), resulting in fan stall" which I can print out and read. Centrifugal, axial and or mixed-flow fans included. I have not had much luck doing a Google search on my own, perhaps I'm...

My lab partners and I did an experiment for my general physics class in which we constructed a windmill with wooden dowels. We added clay to the ends to set the concentration of mass about the ends. The distance (radius) of the clay balls from the center of the fixed axis is our control...

Hello, I need figure out the torque is required to spin a fan blade at a certain speed. I know it doesn't particularly matter how big the fan is, but how heavy it is. I know a 1gm fan is much easier to turn than a 2gm fan. Can anyone help me?

I have planed to make a small engine for my RC. I plane to use clay and (balsa layers) wood for structural support. I know clay is relatively heavy, so I only plan to use I tiny amount for the wind tunnel of the plane. Like one other person had mention, I want to use a "cold" jet. I plan on...

Homework Statement A fan loses an 11 gram piece 460mm from the shaft center. It rotates at 1000 RPM and cannot operate if the shaft is out of balance by more than 8%. Prove whether or not the fan can still operate. Homework Equations Fc = mwr2 The Attempt at a Solution I have...

I was just wondering, that if you attached a fan in the front of an airplane wing, would it fly? If so, then how powerful would the fan need to be for a small model airplane, say 0.4m and 1kg, to fly/hover? Or if i made wearable wings, and i put them on, how powerful then would the fan have to...

Hi! I would like to ask for some help regarding a project I am thinking of making. Well, the thing is, I would like to make a vacuum cleaner with just a couple of tupperware "boxes" 8sorry, I don't know how you english people refer them to...:P), some tape to prevent air leak and a 63 CFM pc...

What's the purpose of "thrust balance" in Turbo Fan Engine? I'd like to know about the purpose of the Thrust balance system in commercial Turbo Fan Engine. Can you tell me the major role of thrust balance system? Also, the relations between thrust balance system and compressor / main bearing...

I think a ceiling fan would increase air pressure in a room, whilst an exhaust fan would decrease pressure if it was withdrawing air from the room. However with an exhaust fan, If the room was sealed off, wouldn't air tend to flow inwards through the exhaust fan as well in an attempt to equalize...

A ceiling fan is rotating 1.0 rev/s. when turned off, it slows uniformly to a stop in 2.4 min. How many revolutions does the fan make in this time? Using the result from the above question, find the number of revolutions the fan must make for its speed to decrease from 1.0 rev/s to 0.50...

I am looking for a replacement for a fan motor the runs off of induction from attached bus work. It is very specialized and I have not been able to find a manufacture. It was made by GE but not for years The original motor: MOTOR, ELECTROMAGNETIC;CANADIAN GENERAL ELECTRIC...

Hello, I need help with my fourth-year design project. The part that I need particular help with is how to design an evaporator and how to size the fan that will create the forced convection over the fins. What are the main things to consider in terms of design steps? What are some good...

Hi, my brother asked me to troubleshoot his electrical house fan. He tripped over it and then stepped on the fan blade which then caused one of the fan blade rivets to break off. A closer inspection revealed that the rivet did break off, however, the bracket that is attached to the electrical...

Hello, I was wondering if anyone could help me wire up a solar panel to a 12v fan. At first i thought it would work if you were to hook up the solar panel straight to the fan but it didn't. I'm not much of an EE, but i ask for anyone's help and understanding. What i have is...

Hi guys, Recently i had noticed that when i left the hot water in the shower on for a while, the mirrors would fog up if i didnt turn the fan on, so what I am wondering is how is it that the fan can prevent the windows from fogging up, I am assuming the windows fog up because of water vapor...

Hi, I was lying in bed unable to get back to sleep and I was thinking about something, remembered this forum, and thought I'd post it up here. Hopefully this topic is suitable for this forum. I installed a ceiling fan in my bedroom yesterday. Its a nice 44in Hunter fan and I'm pretty happy...

Homework Statement An electric ceiling fan is rotating about a fixed axis with an initial angular velocity of 0.290 rev/s. The angular acceleration is 0.888 rev/s^2. Its blades form a circle of diameter 0.740 m. Through how many revolutions has the blade turned in the time interval 0.208 s...

Hi Eureka I'd like to make a solar powered fan, but don't know how to convert the power from a solar panel to the fan. Perhaps I don't have to do anything, I can just hook it up? Requirement: If the sun is out the fan should be running. At night time the fan should not run. In other...

I am graduating soon with a BA in chemistry and after 4 years I decided it's not a subject I particularly like. I don't want to do any more bench chemistry (working with liquids and beakers and pipettes and titrations). I am thinking about chemical engineering though and I was wondering...

I'm considering building a little solar-powered garage ventilation system. My garage faces SSW and gets very hot on a summer afternoon. There is no energy savings involved in this, and I'm probably willing to pay about $100 just to screw around with a solar cell and fan. If I do this, I'll do...

:confused:Hi all, I’m new here; my name is Kris aged 53 in Norfolk, UK. I’ve been in engineering design all my life so they few theories and ideas I may submit for comment do have some sound basis. Anyway, today lesson (for you to teach me) concerns Jet Thrust and ducted fan motors. I...

I have to design a power transmission from a motor to a fan. There are no restrictions on what I design. I'm not sure whether I should use a direct (flexible) coupling, a universal joint, or a belt drive. I have designed a belt drive before, and from looking at catalogues, it looks like it's...

I have a notebook computer, Averatec model number 6240, that is loud like a lawnmower. The fan has already been replaced three times (at no cost to me, under the store's maintenance agreement) and now it's doing it for the fourth time! Only a few months after the last repair, it's doing it...

Hi, i need to know how to calculate the moment of inertia of a centrifugal fan. I searched the forum but didint find any formula... So please people help me

Hey guys. I am trying to put a fan into a helmet. I have a 3.7VDC, 650mAh lithium ion rechargable battery. I have sourced and found a great battery! The afore mentioned battery is the constant. Now I am having problems finding a DC Fan that will work with my battery. So far I have found only 5V...

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...

How would you go about calculating the energy required to propel water through a circular-type blade at 3 metres per second?? Thanks.

flying a model Mig29

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.