Questions tagged [fan]
The fan tag has no usage guidance.
25 questions
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Strange air vents in my office. Is it safe?
On my office ceiling there are a few air vents. They are usually inactive, yet a few days per year (for some incomprehensible reason) they start working, and air flows in.
What concerns me is the ...
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2
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FreeCAD/OpenFOAM vs Paid CFD Software
I am a mechanical engineer who is dipping his toes in CFD for a work project, where we have an array of axial fans in a tower and we're trying to optimise the airflow (its actually two towers facing ...
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are ducted fans better than turbines generating vaccum?
Basically I want to make a trap that sucks mosquitoes into a screen container for future studies, to do this I need to generate a vacuum and I need to choose whether to use a ducted fan (simpler) or ...
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Why is the fan efficiency zero at high flow rate?
How is the fan efficiency zero at the highest flowrate point (at which there is zero pressure rise)? I know the fan efficiency is given as
$fan\_efficiency = output\_power/input\_power$
where ...
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How can I estimate the shape of stator vanes to straighten the flow of an axial fan?
I have an axial 140 mm fan which I need to connect to a duct and I need to design a converging duct as adaptor from circular to the shape and size of the duct I have.
From past experiences, an axial ...
- 169
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Aerodynamic design and characteristic of fan vs blower
I just learnt about the difference between a fan and a blower, namely the former providing high flow rate at very low outlet pressure (<1.1*inlet) and the latter providing a slightly increased ...
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95
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Help me choose an approach to gpu cooler design
I want to remake my gpu's cooler cause the original fans have a terrible bearing sound on low rpm and no amount of software solution helped.
Anyway, I want to use 3x nf-a9x14 pwm 92mm fans as its fits ...
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41
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What are rule of thumb or technical standard for industrial fan?
I want to design a small centrifugal fan to transport wood dust. Is there any Handbook or ISO/DIN/ASME standard for industrial fan? For example, number of blade, hub size, shaft diameter, blade ...
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129
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Why does my self-made air pump not blow air in the correct direction?
I am embarking on a project for building a low-noise air pump for use with things such as air mattresses or pool toys. I just find that the pumps sold at stores are way too noisy, plus it looked like ...
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Why does a centrifugal fan work better than an axial fan for high pressure drop systems?
I read that this is true, but I cannot understand why. Conversely, I heard that Axial fans are better for low pressure systems where large volumes of air need to be moved.
More info on centrifugal vs ...
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Failure of component due to natural frequency vs stress
lets take a component like a fan blade as an example. Is it right to conclude that it will fail even when the stress is within permissible limits but its operating frequency is close (close enough ...
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Radial fan with both input and output on the same plane
An axial fan moves air from one side to the other, where the fan is placed on the plane normal to the axis:
A radial fan, moves air from a normal axis to the same plane where the fan runs:
Is there ...
- 113
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1k
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Multiple inline fans
I have a chimney with a single 100 cfm exhaust fan. If I would add a second similar fan in the same chimney,in line with the first fan, what would happen? Would I move 200 cfm? Would I still move 100 ...
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410
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How to theoretically determine the flow rate for a fan design?
I am trying to design a ducted axial fan. The fan will be pulling air through a filter, and ejecting out into the atmosphere (For a CO2 direct air capture application). However I want to start with ...
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Scroll design for off the shelf tangential/cross flow fan rotor
I'm trying to figure out a somewhat optimized fan scroll shape for a cross flow fan rotor I aquired. However I seem to have vastly underestimated the complexity as I have a lot of trouble finding ...
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What is the purpose of springs in rotor's ventilator/fan
In my lawmower's motor plastic fan/ventilator on rotor has broken to few pieces
There are 2 small springs in fan's slots.
What is the purpose of these springs?
Are there any standards for such ...
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Increasing airflow of fan
I learned at at young age from a physics kit that one can blow up a large bag with your mouth by blowing into it from a distance and letting the air pick more air with it. Later in life when Dyson ...
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is there a difference in performance between these two fan designs
These two fans are usually used in hairdryer is there a difference between them in performance if both have same rpm and same outer diameter.
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128
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Routing the flow from an axial "box" fan
I have a project where I need to generate a certain flow rate to levitate a ping pong ball using the Bernoulli principle. From some rough calculations, I found that it would take about 30 CFM through ...
- 169
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113
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How does temperature not affect fan airflow?
Please correct me if I am wrong : fans are devices moving a constant volume of air, given a constant rotation speed.
Though, flowrate depends of the total resistance of a circuit and the ability of ...
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298
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How can a fan keep spinning normally but suddenly move very little air?
I have a small portable fan, around 15 cm in diameter and lately it is behaving oddly.
Basically I turn it on, the airflow is good but then after 10 minutes or 30 minutes or sometimes hours, the ...
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Why does the manual to my floor fan tell me to pull out the cord whenever it's not in use?
In the manual to my just-bought floor fan, it says this (among many other weird requirements/expectations):
Pull out the plug from the power point when the product is not in use. Do not pull the ...
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How to select a fan blade for my application (strong, focused breeze)
My question is how fan blade design relates to the focus of the air leaving the fan. I am looking to generate the most focused breeze I can with a fan blade, excluding additional ducting etc, the fan ...
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Fan performance curve
I am being asked to compare a fan which is going obsolete with its proposed replacement. From a mechanical and electrical point of view, they are almost completely identical so I have no concerns from ...
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What size of fan requires motors with a transmission? [closed]
I am wondering at what fan size/speed a direct drive motor is no longer sufficient to drive a fan? Phrased alternatively, what size/speed of fan requires motors with a transmission? For an axial fan.
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