Fan Definition and 338 Threads

Hello. I need an explanation for a strange phenomenon ... I use a fan (PC type) powered by mains (220 V / 50 Hz in my country). At a distance of about 3', I get a sin EM field (sure it is not by mains cords) at a stable frequency of 200 Hz synchronized on main frequency. Even during power on...

I am building a Cigar Humidor, and need to have a fan control to operate 18 3.5"Computer Fans simotaniously as well as controll there speed. Here are some specs on the fans... Rated Voltage: 10.8~13.2VDC Starting Voltage: 7VDC Rated Current: 0.16A Power Input: 1.92W I have found...

Is there an equation with which I can estimate the flow rate a fan will generate at a set diameter, speed and angle of the blades? Assume that this is a simple box fan that you would put in your window. I'm assuming that you would have to determine the axial speed of the air given the angle...

I wonder if there is a mathematical formula to calculate the flow rate of a fan if following parameter are known Fan effective diameters Blade Angle ( Pitch ) Number of Blades Speed ( RPM ) Power Consumption Pressure at inlet of the fan Regards

Bernoulli"s Principal would a fan matter? If you have air moving through a 3' tube connected to a 1' tube with a taperd connection. Than the pressure in the 3' tube would be greater than the 1' tube due to the speed in the 1' tube being higher than the 3' tube, correct? Then if you put a...

My friends (all A&P Aircraft mechanics) say I'm nuts. A co-worker and I attended a Honneywell TFE731 jet engine maintenance school. During the class the instructor asked this question, "which side of the front fan on a TFE731 engine has the highest pressure?" His answer was the front. (we are...

Homework Statement Can the addition of a second set of fan blades, below the first set and on the same axis, improve the lift force created? What is the theory associated with this phenomena? Homework Equations none, practical application in lab setting. The Attempt at a Solution...

What follows will be a very practical question for the winter months. I'm a senior math major who appreciates efficiency. And saving money, I like that too. As it turns out, the heater in my apartment eats money like there's no tomorrow, so it generally tends to be left off for obvious...

I looked, but didn't see any post on this topic. This is in regards to the selection process for fans/blowers in ventilation systems, which I am still new to. From AC/Hr and the room volume we know the required CFM we need to supply to the space, and we can determine the size of ducts and FPM...

We are trying to improve the efficiency of a fan for an engineering project. However, we first need to figure out what the efficiency of the fan is now. Since we know how many watts the fans motor is using at each setting, we figured we could just find how much power is in the air the fan is...

I have a question regarding the relationship between airflow restriction and fan power. If the pressure drop across an airflow restrictor (filter bank, heat exchanger coils, etc.) is known by measuring with a magnehelic differential pressure gage and that dP changes (filter replacement/removal...

if a fan with a battery is placed in space outside Earth and if it is switched on... then what will happen? will the fan go ahead, behind or will it remain at the same position?

A ceiling fan consists of a small cylindrical disk with 5 thin rods coming from the center. The disk has mass md = 2.9 kg and radius R = 0.26 m. The rods each have mass mr = 1.4 kg and length L = 0.8 m. When the fan is turned on, it takes t = 3 s and a total of 15 revolutions to accelerate up...

Is the only reason air moving over your body caused by a fan or breeze feels cool because of increased evaporation of moisture from your skin? Or does it blow air being warmed by your skin away from your body to be replaced with relatively cooler air? Also, does air movement also produce...

Hey guys, I'm a college student looking to build a miniature RC plane based off this picture here: [PLAIN]http://www.kruxor.com/wp-content/uploads/2010/07/SC2_Banshee_Art.jpg As you can see, the thrust needed to lift and mobilize the plane is provided by the two fans on the sides (does this...

What I'm tring to do is connect FAN 2 Wiring (673 DKBLU 2nd picture top diagram) to The Auto pole of the AUTO/ON/OFF switch so I can manually activate the FAN if needed. I'm a little confused since in the 2nd pic, I don't see a Negative side to the coil on the relay. Can/will this work?

I would like to power a duct booster fan (which I believe uses little energy) using solar panels. The store website says the fan runs at .35 Amps. The solar panel would get direct sunlight for about 3 hours a day and indirect sunlight the rest of the day. I would like the fan to run at least...

I am working on a project where we are using ducted fans and just recently we were testing to effect of some bellmouth inlets we made for the ducts. At full throttle the thrust for the fans with no bellmouth inlet was approximately 8.8 lbs and with the inlet the thrust was approximately 10.5...

I am having a discussion with a co-worker. He doesn't believe that the curvature of a fan blade has any effect on efficiency. That one simple has to reverse the direction off rotation to get full flow in either direction. I know this isn't the case but am having a difficult time explaining and...

my fan has stopped working recently, when i turn it on it makes hamming voice, but it doen't work, what might be the problem?

Hi all, I am wondering that we should choose fast or slow function of electric Fan in hot weather, which function will spend much more of energy?, can someone give me an explanation :D Forgive me if the questions is silly

First I thought of posting this on the random thoughts thread, but I need an answer to this bugging question. Why the hell a microwave (the cooking device) makes that fanlike noise? While an infrared device (electric heater), visible light device (a flashlight), x-ray machine do not make any...

Rotation of a Fan - Unsolved Homework Statement A ceiling fan with 85cm diameter blades is turning at 66 rpm. Suppose the fan coasts to a stop 26 s after being turned off. What is the speed of the tip of a blade 10 sec after the fan is turned off? Homework Equations...

I remember once observing a thread in a discussion forum by someone trying to build a backpack helicopter. Various people warned him about sprung-weight-vs-unsprung-weight, hazards of stability and flight control, etc. But ever since reading about James Dyson's bladeless fan and the...

I am curious as to how a portable fan works. I took one apart and here are some pictures of the motor: https://docs.google.com/leaf?id=0B9FkpE8S_7W0NTEwOGZlYzUtMzhkNS00ZmU4LWE5ODItN2Q5NWViNDNmOGMz&hl=en&invite=CIrB408"...

I am trying to figure out how to get cool air. Say, if I have a fan and ice cubes. Should the ice cubes be in front of the fan(air blowing at them) or back of the fan (fan sucking). When I did it, I couldn't feel the difference.

Hey all, I am working on a 0-40V variable power supply right now, and while the power supply is working I am wondering if it is in danger of overheating. I am using a LM317 with a 0-5k potentiometer between adjust and ground, and a 165ohm resistor between output and adjust. Input is regulated...

1. The blades of a ceiling fan have a radius of 0.318 m and are rotating about a fixed axis with an angular velocity of +1.48 rad/s. When the switch on the fan is turned to a higher speed, the blades acquire an angular acceleration of +2.22 rad/s2. After 0.394 s have elapsed since the switch was...

Ok i have the following problem, I have a fan connected to the nozzle, i am given the nozzle area and the volumetric flow rate generated by the fan. How can i find the velocity of the air at different distances from the tip of the nozzle? any help is greatly appreciated

Hi friends, My air conditioner is a split one (it has 2 parts: one inside the house and the other outside). It has 4 modes of operation: cool, fan, and 2 other modes. My question is that what does the machine really do in the fan mode? I wonder whether it just serves as a normal fan...

Hi, my name is Steve.. I am working on a ducted fan. I want to simulate it in Fluent in order to optimize my design. I know that sliding mesh technique and multiple reference frame method will be used but I am having problems in Gambit. I do not know how to model it in Gambit. I have made...

This is cool. This is a one-bladed fan. And now I know how to upload to YouTube...

We have adapted a 60W A/C Fan Motor, 1500 RPM to run two spindles one at 6000 RPM and the other at 500 RPM using pulley & belt. On continuous use the motor heats up excessively and a few fail. Load is winding of threads from a Cone to a bobbin. I need a few suggestion i) Can rewinding...

I built the unit linked below several years ago. I wanted to rebuild it to utilize a electrostatic filter and bag filter. Right now I just run 2 filters (11 merv) before the fans and 1 filter (11 merv) after the fans. I know things like design, filters, etc all work into the calculations of...

Here's a question that I thought up while shooting darts through a five-bladed ceiling fan. I'm lazy, so I'll use symbols for the constants in the equation. Say I have a five-bladed fan of radius R, with a blade width W, spinning at angular velocity V. I shoot a dart of length L through the...

hi can anybody explain for me why some fans blow the air and some suck the air?.I know it depends on the form of its wing, but how?

hi, I am an electronic engineer student and I am doing a study on control systems that can be used to control a ball's height in a vertical wind tunnel. I have a problem in calculating the fans needed (as in size and number of blades) and the amount of cfm that the fans need to produce...

Would the performance of a ducted fan be negatively affected by the presence of a surface flush with the intake of the fan?

for the following SC cube, find the miller indexes for the planes: FAN KFA HAN http://lh6.ggpht.com/_H4Iz7SmBrbk/SvhiU8OeicI/AAAAAAAAB8M/o8QPR2ht2gA/Capture.JPG what i leared to do was find the points that the plane intercepts the x,y,z axis, i chose axes such that x+ is pointing...

I am not talking about superstrings, but the idea of supersymmetry itself. Let me say what annoys me. I will put aside the advantages of it satisfying Coleman-Mandula theorem or solving the instabilities of the Higgs field, lorentz invariance or any other consistency that it satisfies in...

Let's say we have a rectangular surface or something. How about a piece of plywood. If we were to blow air say using a fan at the top of the wood and keep the air "calm" at the bottom, would it create lift? I know it's not practical but in theory should there be a slight lift?

I am looking at fan curves here at work and I stumbled upon this one. Its for an 80mm diameter tube axial fan. What's up with the Flowrate vs RPM curve (the dashed line)? In the flowrate interval between 12 - 23 CFM there are instances of the same RPM for different flowrates. That...

Dyson, the same guy who invented the bagless vacuum cleaners, has now come out with a bladeless fan: http://www.time.com/time/health/article/0,8599,1931455,00.html That makes me wonder - could similar principles be used to come up with a bladeless wind turbine? Some environmentalists are...

Hey everybody, I am about to make some simplistic fan analysis for a hubbed axial flow fan (Single stage). What makes me confused is if I should use the classical "one stage" approach for compressor design or if there is another way to do this?! My aim is to carry out a simplistic analysis of...

I currently doing by final project about designing fan for turbofan engine.After discussing with my lecturer,I decided to do it based on axial compressor preliminary design method in Gas Turbine Theory : G. F. C. Rogers, H. I. H. Saravanamuttoo, Henry Cohen book.Now after following the design...

I have a test application that required a high velocity (subsonic) air trough a restriction in a close loop system. I would like to know which circulating fan would be suitable (axial, centrifugal, mixed flow, turbo) since the fan will have a backpressure from the close loop arrangement...

Hi there, I'm renting, so can't add power sockets and wires to my flat. My bathroom is windowless and passively vented. I'm going to put a solar panel on the roof and drop a wire down the chimney. I was thinking about getting a 7.5v 2.5w solar panel and a fan and directly connect them -...

I am working on a project that requires 4 ducted fans, each producing approximately 40 N of thrust for approximately 10 minutes using battery power. Is this feasible? Any suggestions about which fan and battery I should use if it is feasible? Thanks

Hi, I'm currently designing the ventillation for a number of pump stations for a large water pipeline. Essentially this will mainly involve forced air cooling, to keep the space within 5degress of ambient (i.e. no air conditioning). My question has to with fan and and air filter...

Hi, I have a fan heater which is rated at 2kW but when we check what it is actually using (voltage x current) it is only using 0.7kW. I am curious as to why this is? This is the fan: http://www.amazon.com/dp/B000306BL4/?tag=pfamazon01-20 Are these fans 100% efficient? Thanks...