Fan Definition and 347 Threads

Damn title character limits. I just had the weirdest thought while rearranging my computer's case fans. I put my hand in front of one of them and felt a light breeze of air, telling me it was working. This is due to the local cooling produced where the fan's airstream comes in contact with the...

Hi there, I have recently observed a strange effect regarding a fan and was wondering if someone could explain what's going on. I have a 22cm computer case fan which I am using in a project. For my purposes, I had to partially tape over the back of the fan. I also put a large plastic jar lid...

I am having a wood burning stove installed soon. I am wondering which would be better, to put on the top and aid room circulation, an electric fan, powered from a Peltier junction or one using a Stirling Engine. Does anyone have any ideas or experience about this? I wouldn't expect 'efficiency'...

Hi folks.I'm 3rd grade mechanical engineering student.I want to make cpu cooler.I will make pid controlled fan with an arduino. PID path is easy but I could not find anything about fan dynamics. I want to design my own fan.I need something like "fundamentals of fans" that should answer my...

Hello, I am moving into a new house, remodeling, etc. & am installing a new A/C compressor and radon fan. Being that low frequency noise highly bothers me & affects my insomnia quite a bit, I am trying to look at all considerations regarding acoustics, mechanical sound propagation properties...

Hi I'm working on a project where I would need to lift about 400 pounds about 1 inch off the ground and keep the momentum in order to manually move it. I thought about using four fans with a skit on each corner facing downward to allow for upward movement, but I'm not sure how much power I would...

Hello I am trying to design a vacuum using venturi. I cannot quite get the air flow created by the rotation of the fan, which is connected to the engine. How is the relation between the fan speed and the flow rate created by it? I know the proportionalities between the speed, power and the...

Is there any equation for pressure generated by a fan, specifically a centrifugal blower. On the web I found this page where the author uses Pressure = 1/2*rho*v^2 where rho = air density (kg/m3) v = tip velocity of fan impeller (m/s) Pressure = pascals I haven't found additional info on...

Hi guys, I recently completed a fluid dynamics practical at Uni and submitted a report on it, however, I still have some burning questions which I need to be answered. Firstly, the data that we collected shows that as the flow rate in the duct increases, the pressure differential of the fan...

actually i searched a lot regarding this question but didnt find exact answer anywhere.some say electricity bill reduces some vice versa.do all extra voltage is dissipated as heat? in the regulator,or current drawn remains same or only partially dissipated as heat.Thanks.

Dear All, Would you please guide me regarding I want to make a mist fan. A low level mist is required almost 4 to 5 feet. I need all information regarding tube dia, nozzal specification specially pump specification. Thanks in advance. Regards, Kashif Usman

I just noticed this and it is crazy. I have a little speaker that I plug into my computer. it is being charged by the usb port. I got up and turned off the fan in my room and I heard a popping noise. It worried me a bit, so I turned the fan back on (no noise), then I turned it off and I heard...

Homework Statement 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 = 0.22 m. The rods each have mass mr = 1.4 kg and length L = 0.83 m. 1) What is the moment of inertia of each rod about the axis of rotation...

Ello, does anyone here understand how a standard overhead fan and air flow works? If so, what would happen if you're just chilling in your room with the door closed,windows shut and fan off, then the fan just speeds up to around90% thespeed of light for a second. Would that kill me, suck me...

Hey, I'm trying to find a fan that will dissipate 1471.5W. The fan is going to be driven via a belt connected to a driving spool and not driven by an electric motor. How do i go about calculating the required fan size? Is there anywhere i can look at fan specifications for fans that are not...

Okay so I've had my PC for 5 years and my sidepanel intake fan is shot and I was wondering how to know what fan I need to replace it or if any standard intake fan would work?

hey, I am building a fan, but I need the fan blade to move relatively slow, slow enough to see each panel on the blade. I am expecting to use a gear system with a belt. What gears should I use to active this?

On what does the cfm of fan depend ? how to gain maximum cfm from a 1800 rpm fan ?

how to design a circuit to determine the rpm and torque from a fan?

I have been tasked to design a controlled descender to be used on a building site to lower tools/rubble to the ground. I'm trying to design a product like a fan descender like that seen at powerfan.co.uk Could anyone help me with the theory side of its operation. Obviously it uses the fans...

Hello! I am an electronics engineer and the only time I came across Fluid mechanics was in class 12. I have been stuck for a long time in the finalization of a product. The difficulty is that I need to design a heat-sink, place a fan over it and perform a thermo-fluid simulation of the system...

If I turn on a standing fan in my room how does the speed of sound change in the fast moving air compared to the still air around it? Would it be relatively faster, slower, or does it depend on the direction in which the fan is blowing?

Homework Statement Hi, I am trying to work out the energy needed to move a certain quantity of (ideal) gas using a fan but am finding a great discrepancy between my calculations and those supplied by the fan manufacturers. let's say i'd like to move 1kg of air (1kg/m3) a distance of 1m. I get...

Hi Guys, I just want to ask if there is a relation between fan RPM and the fan power consumption. Because in some specifications I see, Power consumption is not consistently increasing as you increase the Fan RPM. If we lower the RPM , will we still achieve the same airflow? if we always set at...

I recently shifted to South Korea to pursue higher studies and stay with my sister and niece . My niece is working on a high school project on air pollution and indoor air quality studies . Starting with a write up on air pollution and then indoor air quality and effects on health and the...

My husband asked a question earlier this evening, which has given me pause. I've looked everywhere I can think of and came across this forum. Maybe someone here knows the answer. Why do ceiling fans (and similar residential/box style fans) go from the off position to the highest possible speed...

Anyone can show me how the velocity diagram at the inlet and outlet of a airfoil section ceiling fan blade?

For the final year project that i am doing, I need to design a high efficiency ceiling fan blade with airfoil section, tapered and also twisting. Can anyone tell me how can i obtain the optimum pitch angle for different section of my ceiling fan blade?

Hello, I was hoping someone on here could suggest some affordable software to model the flow produced by a ducted fan. I saw someone using Solidworks flow simulation, which is convenient because I can use SW to model the fan AND get a rough estimate of the thrust produced. I'm not looking for...

For finding fan performance curve where better to put static pressure probes - near the surface or near the center of the duct ?

In particular I am wondering about compressor blades, but it's an interesting question to pose for household type fans as well. We can imagine "waterwheel" type schemes, and also the more traditional schemes where the axis of rotation is parallel to the flow. Which produces more noise per...

I am to choose a certain type of jet fan in a parking garage. Looking at a spesific one, what I'm having a hard time considering is the noise it generates - 78 dB (A) at 3 m - and whether it would within acceptable limits? This is a fan that you would pass underneath walking to or from your car...

Hi all, I was thinking of doing an experiment with axial fan for determining it's stall condition. By stall, here, I mean airfoil stall. I want to do this experiment in order to gain a firm grasp on the concept of stall. I have read the theory but an experiment would definitely give me an...

Homework Statement A ceiling fan consists of a small cylindrical disk with 5 thin rods coming from the center. The disk has mass md = 3.3 kg and radius R = 0.26 m. The rods each have mass mr = 1.2 kg and length L = 0.72 m. What is the moment of inertia of each rod about the axis of rotation...

Homework Statement A person living in a 4m x 5m x 5m room turns on a 100-W fan before he leaves a warm room at 100kPa, 30 degrees Celsius, hoping that when he returned in 5 hours, the room would be cooler. Disregarding any heat transfer determine the temperature of the room when he comes back...

If fan blades move in a circular way how is the air moving towards you (in front of fan) ? Also propeller and fan have different shapes, does it mean they work different?

Dear all I'm designing an exhaust system for a wood working facility. Please correct me if I'm wrong as I'm new to this industry: The system needs about 4.8 m^3/s airflow (with main duct velocity of 20m/s and branch velocity of 23 m/s). The total pressure drop due to the ducts and...

I created a diagram of 5 scenarios in which I would like to understand how their variations would affect air flow and suction. Examples attached to post or link to examples: http://s29.postimg.org/kua3svg2f/understanding_airflow.png So onto the actual question, how will air flow and suction...

So I want to design a propeller that will slow down a motor and I want to know what formulas or equations I would use to calculate that torque. Also, if I decided I wanted to run it in a fluid, what it just be a matter of density change? I have attached a picture of what I want to do. Thanks

Hi, Looking at blower fan charts, why does the static pressure drop with increased CFM, what makes sense to me should be a pressure difference rise with increasing CFM.

Hello everyone, Firstly thank you for taking the time to read this! I am a complete electrics beginner, so forgive anything stupid I say. I'm also typing this on a phone, so sorry for the odd nonsensical word! So here is what I am trying to do: I have a small greenhouse, the plastic kind...

Other people must have come up with this before, but what if we attach a lever to a rotating fan. The lever can be attached to a bulb to run it, or maybe something like a Leyden jar or a KERS, (mind me if its the wrong device, i am just a rookie) to store it. So won't the house be self sufficient?

The attachment provided shows a frame in which a large fan is to be rested on. The fan is to remain static and has a weight of 6,060 kg and the location of the centre of gravity is shown in the attachment. Each frame member has a cross-section of 200h x 90w. I would like to know HOW to calculate...

Hello, I am trying to compare different combinations of Radiators and fans on their ability to cool water(or any liquid for that matter) Now I've been showen some Bernoulli's equation things and been pointed at Reynolds number but To be honest I haven't looked at any physics outside rigid...

I posted this question in a wood/coal stove forum and after 100 responses, we do not have a convincing answer: Will MORE heat be extracted from a heated metal object if you put a fan on it? If we have a simple electric resistance heater (a glorified toaster) making 10,000 BTU's, it seems...

Here's a random question from the depths of my brain. :) Say that there's a sailboat on a flat, empty lake. Now imagine that on the boat, behind the sail there's a big electric fan. If the fan were to be switched on(blowing towards the sail), would the boat move forwards, backwards, or...

I have a VFD fan that pushes air through a filter. Over time, downstream resistance gets higher due to the filter. Fan speed remains constant. We have looked at amperage draw and it has remained stable even with this added resistance. Does that mean that air flow remains constant? Kind of...

I was wondering if anyone could help me with this. I have a 200mm LED fan that currently has blue LEDs in it. I would like to swap them out for tri-color LEDs and run a switch through the LED loop to control which LED would turn on. I want to mount the switch into a PCI slot in the back of...

My understanding is that when a fan begins spinning, a partial vacuum is created. Physically, what creates this partial vacuum? Does the motion of the blades create a void in which there are fewer air molecules than in the ambient air and thus the pressure is lower than the ambient pressure?

Hi everybody! I'm currently working on a project where a wet cooling tower is involved. The wet cooling tower is an induced draft system. I know the volume of air handled and also the properties of the air entering and leaving the system. I want to determine the electricity consumption of...