Fan Definition and 338 Threads

Hi, This is my first post on the PhysicsFormus I am trying to design an inlet and outlet for an axial fan and calculate velocity and pressure profiles in the duct. See the sketch attached. The ultimate goal is to carry out a CFD study but I was wondering if there is an analytical solution for...

Is there a cooling fan with a heat sink on the Smartphones CPU - Quadcore processor and above similar to the desktop and Server CPU? If not, why?. Is it not required? Thanks & Regards, Prashant S Akerkar

Let us assume we have a cylindrical wind tunnel having a 0.5 m diameter fed by an electric fan. The cross-sectional area of the wind tunnel would be A1 = (PI/4) D1^2 = 0.196349541 m2. Let us suppose the motor driving the fan has a power rating of 1,500 W. At this stage, let us assume that the...

I'm making a ventilation system with a fan that will blow air through a 1700mm long pipe that has a 45 degree bent in the middle. I should decide on a pipe diameter of 125mm or 160mm. Also I need to choose between 3 different fans that has the following specs from the manufacturer: 120mm fan...

Any cooling fan, as well as any objects that it cools, will invariably become choked with fine dust after a time. But this seems quite surprising considering that all the dust is being accumulated on surfaces that are exposed to large currents of moving air. I've learned of two possible...

Hello! I am building a recording studio which will be air tight and will need fresh air intake and stale air exhaust. I have a general question regarding which is better, using one or two inline fans for the job? I was told that that you could have one fan on the exhaust duct which can pull out...

Good day! How do I calculate how much torque I need in a motor for my project? I must rotate a 100lb propellor, which is 11 ft in diameter, at 1 rpm .

What is basic and advanced physics mechanism behind this ceiling can? Why it rotates in one direction? Why it can't rotate reversely ? How air is supplied by this fan ?

I have a 5/8" hex shaft that is turning at 90 RPM that I need to add a 2.7 N.m load to it. The shaft is running in a dust box. I would like to mount a fan on the hex shaft to create the torque but I am unsure how to calculate the torque that would be added by the fan. Would anyone be able to...

i made a small thing for my nephew, i connected two small fan motors with one switch and one battery but everytime one of the motors jams or he grabs the fan the other fan rotates faster. why is that? also tried to increase number of batteries but same thing

A ceiling fan has kinetic Momentum in 1 blade hitting a fixed target. Would the design allow the other blades to flex , reducing target impact? If the 4 blades are combined and bolted together at same velocity is different Momentum delivered? Similar q : a human arm is about 8kg and a sword...

Can adding a nacelle in front or behind a standard pedestal fan affect the speed of the air coming in and out? If so, which is more beneficial: an intake nacelle or a nacelle in the front? Using Q=AV, with Q being constant because of the fan blade's max speed, can affecting the area (A) create...

Fan makes me wonder the Vicinity of Physics. The fan is rotating at an anti-clockwise direction & it is suspended from the ceiling by a cylindrical handle. Now the fun starts here... According to Newton's 3rd law every action has its opposite reaction. That means the anti-clockwise angular...

Hi All, I have a VFD running supply fans and I currently have two values I can see. One is the VFD actual speed percentage from the VFD. The other is a calculated Fan Speed based off of VFD current. (I control off the calculation). The calculation is (Current^.33)*25.54=%. Does anyone know this...

Hi all, I am trying to design a open circuit wind tunnel, and I've got to the point where a fan should be selected. However, I am not familiar with fans at all, so I am wondering if you could help me! My understanding is that the fan selection process is quite similar to the pump selection...

I have a 3x3.5 (meters) room with a bathroom of approximately 1.5 x 2. I want to know whether to close the door or not, If I running Fan Mode. There is wall in front of my door, about 60 cm, My assumption: Fan mode only circulate the air, If I open the door, I'll bring outside air in, which is...

I have a capacitor from a fan. The electrician says it's dead, but I think he is lying. I want to test it with a multimeter. But I can't identify which terminal is positive or negative as it's old and from local company. A poor video of the capacitor is below: A few pics from the video...

due to a design issue I'm trying to figur out whether i can get enough thrust to lift a 150-200 kg using some costume made radial fan instead of the usual propellers for a little vtol drone I'm willing to produce. any comment will be much appreciate. Thanks.

Hi everyone! I was wondering if there is a known equation to calculate how the speed of a fan affects the cooling of a heat source. Is there a way to calculate this or know what type of relationship it is? Thanks!

Homework Statement Hello, I have a task to make a heat balance of the evaporator. To do this, I was told to carry a few smaller energy balances in different parts of the evaporator. One of the things I had to calculate was the heat generated during steam compression. -steam is entering...

I 90% understand the question and solution but unfortunately I have some hesitations about the formal solution in the book. First of all, when calculating P4-P3, choosing lines and points on them, why do book assume velocities of 3 and 4 to be the same...

I'm trying to calculate the air flow decrease of a backward inclined centrifugal fan with inlet bell house with expanded metal installed. The air flow of the fan is 18,400 cfm, 2.6 total static pressure drop, 1540 RPM, 100 deg. air. Orig. equipment did not have this expanded metal on the inlet...

Homework Statement Homework EquationsThe Attempt at a Solution

Good evening to all...I am troubling with a doubt that how a propeller differs from a fan regarding jet engines..

I am try to build a magnetic motor using a computer fan on the basis of a video I saw on YouTube. I have placed 4 neodymium magnets at the edges of the fans frame. However the fan has failed to spin from the magnetic field created by the magnets. How can I find the correct orientation in order...

Hi all great PF members, Can anyone help me to sizing fan static pressure strong enough to open a metal cover an angle 15 degree at the end of the duct (20m in length with few 90 degree bends), I'm really not good at math so any help are greatly appreciated. Please refer to sketch attached for...

Hi - I'm a writer/editor/writing coach/teacher, now retired - alas, more due to disability rather than age. My speciality when I was working was various sorts of non-fiction. I particularly enjoyed coaching professionals writing their first books, on various topics in business, the non-profit...

I'm Brazilian, and until a few years ago most commercial electric fans sold in the country looked like this: But then one company started making them with 6 blades, claiming it had better wind output and made less noise than the 3-bladed fans (they didn't directly made this claim; it was...

Homework Statement A 2.34-kg cart on a long, level, low-friction track is heading for a small electric fan at 0.22 m/s . The fan, which was initially off, is turned on. As the fan speeds up, the magnitude of the force it exerts on the cart is given by at2, where a = 0.0200 N/s2. What is the...

Single fan is enough for 6800K? like Thermaltake CLW0222-B Liquid CPU Fan or Cooler Master SEIDON 120V Plus Liquid CPU Cooling Fan. I want a ans which better for me 2 fan cooler or single fan cooler? note: My PC should be RUN minimum 14h/day

How can you calculate air volume in cubic feet per minute through a fan when the only data available is pressure drop and fan diameter? For example, How many cubic feet per minute of air is a fan blowing if it has a diameter of 20" and a pressure drop of -50 pascals?

I want to design a device that will require a small dc fan that may have to operate for long periods with fog-like moisture passing through it. Is there any advice on what to look for?

I have a 24 volt power supply to power a 12 volt fan. Since I don't want to burn the motor out I used a voltage divider with two 1kΩ resisters to cut the voltage in half. I measured that the voltage on the divider is 12 V, so this is good. However, it won't drive the fan. When I hook the fan...

One of my classmate asked me a question that Why we used capacitor in the fan ? I gave her the answer but she said the answer in not fully appropriate ! Any one give me proper explanation of this question ?

Would a fan with half the blade length be more efficient? My reasoning is that there would be less mass to spin, also a shorter blade length would make the lever arm smaller thus reducing more of the torque the air would create on the blade.

the vw type 1 engine comes with flaps that close when the engine is cold. i know the flow through the fan doesn't completely stop but for the sake off argument let's assume that is does. the fan is spinning but there is no flow. what power is required to maintain the pressure differential...

I have an electric fan that looks like this: Recently, when I flip the switch, the fan blades won't start spinning without any initial assistance. I have to manually push the blades to get them going. But this is not due to too much friction, the friction is the same. When I flip the switch...

Every desk fan has it. What's the purpose of the white cap attached to the front fan grille?

I have fan that's 20 V and 14 A. I give it an input of 5V 1A. So my question is... increasing what will increase the performance of my fan more... Current or Voltage??

Picture a circular horizontal piece of duct, open at each end. If a fan is to be placed somewhere along the duct and move a certain amount of air, does it make a difference for the fan and it's operating point where it is positioned? Or does it only come down to the total length of duct and the...

Really quick question, what exactly does the fan of the outside part of my split ac do? That fan seems to just make wind for no clear reason. I'm curious to know what it actually does.

Homework Statement I stumbled upon some thought, suppose we have an electronic fan cart like this https://i.ytimg.com/vi/Zy7JQ0lwj1w/maxresdefault.jpg My question is, when I turn it on and it continue to move, is the power expanded by the fan cart constant? I suspect it is not because it is...

Hi to all, this is my first topic and I hope I'm not in the worng section. As you can see at this link: http://www.skeetty.com/disco.jpg, I have a plate with a diameter of 4 meters which can rotate at 200 RPM. On this platform, I have four fans with 4 blades where the length of each blade is 1...

Homework Statement An electric fan which is plugged into a 115 V(rms), 60 Hz socket in your house can be considered as made up of a 1500 Ω resistor in series with a 1.4 H inductance. How much power is dissipated by this electric fan on the average? (in W) Homework Equations P = IV = I^2 R I =...

Hi, We have an axial fan in the lab that apparently vibrates badly ("wobbles") at certain frequencies. To find the resonance and the bad frequencies, I decided to do an ANSYS modal analysis. I am still pretty new to it, and have a few questions. 1) Regardless of how many modes I pick...

Hi, I've been considering the design of a fan that sucks air radially and blows axially to resolve a technical problem of a machine. I've looked around for the equations governing the air particles and the angle of the radial blades (angle between a flat blade and a radial line) of the fans, but...

Being a non- physicist, it is extremely difficult for me to conceptualize QM. I hope to get some definite help at this forum. QM says that the sub-atomic particles exist as both waves and particles. It is not that much difficult to conceptualize. QM also says that the sub-atomic particles can...

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...