CAD design and finding the most optimum fan shape?

[eBiz]

I must be wrong but it seems like with aerodynamic software and CAD that there would be one single design of fan blades that would be the most efficient. I mean fans have only a few variables, rpm, weight, and fan shape/number of blades. With modern software it seems like they would have found one fan shape that performs best for airflow, another optimized for low decibles, another for pressure optimization.

 

I know there is different designs for these things but I am talking about one singular design for these that could not be approved upon. Is this not acheivable or could be developed with todays software?

 

 

 

 

Also I saw this single bladed fan and thought it was quite interesting. Its claiming to be super efficient.

 

http://dornob.com/contemporary-single-blade-indoor-outdoor-ceiling-fan/

[BurgerBum]

i was thinking the same thing. 

 

i think four types are ~possible~ maximum pressure, maximum air flow, minimal noise, and one that averages all three.

 

but its impossible to just find the best one, because once you've made the perfect design, WHY THE HELL NOT SPEED IT UP.

and after you speed up a certian amount, the material you make it out of wont be able to handle pushing that air out of the way, and we'll move to light metals, but wait, then those light metals will find thier maximum speed. then we'll move to heavier metal, and stronger motors to be able to move those heavy ass blades, but then, wait, those motors are louder than the older ones, so we need to modify the blades again. 

 

 

its just a vicious circle of one increase in preformance cases another problem. 

[eBiz]

i was thinking the same thing. 

 

i think four types are ~possible~ maximum pressure, maximum air flow, minimal noise, and one that averages all three.

 

but its impossible to just find the best one, because once you've made the perfect design, WHY THE HELL NOT SPEED IT UP.

and after you speed up a certian amount, the material you make it out of wont be able to handle pushing that air out of the way, and we'll move to light metals, but wait, then those light metals will find thier maximum speed. then we'll move to heavier metal, and stronger motors to be able to move those heavy ass blades, but then, wait, those motors are louder than the older ones, so we need to modify the blades again. 

 

 

its just a vicious circle of one increase in preformance cases another problem. 

 

 

Hmm. Yeah, I guess you would have to settle on the fan motor first and make the design around that.

[BurgerBum]

lets take the averaged one of noise pressure and speed for example. 

 

so noctua finds this MAGICAL blade design, that uses 5 blades, (5 is just an example) and it has ridges to help air flow, and yadda yaddah yahduh. 

so, noctua has found it. but, whats stopping them from wanting to make it faster? 

now they need to redesign it to be able to widthstand that new speed. 

 

i repeat myself. 

vicious circle of improvement. 

 

as long as its possible to make it faster. they'll need to re-design the blades and enclosure.

[Dicoray]

Look at noctua fans... now you know what close to perfect design looks like (but that color...)

[eBiz]

lets take the averaged one of noise pressure and speed for example. 

 

so noctua finds this MAGICAL blade design, that uses 5 blades, (5 is just an example) and it has ridges to help air flow, and yadda yaddah yahduh. 

so, noctua has found it. but, whats stopping them from wanting to make it faster? 

now they need to redesign it to be able to widthstand that new speed. 

 

i repeat myself. 

vicious circle of improvement. 

 

as long as its possible to make it faster. they'll need to re-design the blades and enclosure.

 

 

I think were saying pretty much the same thing. You start with rpm, say 1500, then design the fan design around that. If they want to make it faster say 2000 rpm, yeah new design for the  increased speed.

[BurgerBum]

Hmm. Yeah, I guess you would have to settle on the fan motor first and make the design around that.

i honestly think the current fan designs are actually pretty much good for a long time. 

also, speaking of fans, whats your opinion of noise level? 

you care? or are you a silence person? 

 

i personally would rather have 2 200mm fans running at a low RPM for each intake side, and exauhst. just be whatever came with the case. x'D (none if thats the CASE... HAH! jokes.... ........................... im dead inside) 

 

 

 

speaking of 200mm. 

after a certian size increase/decrease, any one design will stop being optimal.

[BurgerBum]

Look at noctua fans... now you know what close to perfect design looks like (but that color...)

they have black ones. x'D

[BurgerBum]

I think were saying pretty much the same thing. You start with rpm, say 1500, then design the fan design around that. If they want to make it faster say 2000 rpm, yeah new design for the  increased speed.

yup.

[Dicoray]

they have black ones. x'D

they still have brown corners

[Real_PhillBert]

Believe it or not fans are extremely complex . The performance of any fan is highly dependent not only on the fan blades, but he housing, the RPM, the environment it is pushing air to and the environment it is pulling air from.

 

I am a mechanical engineer that specializes in mathematical analysis, specifically fluid flow. Believe it or not I have designed fans for a major agricultural company, they are several times larger than what is in your case, and compressor designs but fans nun the less.

 

I spent over a year with many many different fans on dynomometers and data acquisition systems, as well as countless designs that were tested using FEA software before we even bothered to produce them. I have Excel sheets that are thousands of pages long and contain millions of points on fan curves. The raw amount of data involved in fan design is truly spectacular. 

 

All fans are a balancing act on a couple of variables, RPM, the amount of static pressure it creates, and the amount of CFM it displaces. But because air is a compressible fluid you cannot make a fan with both (relatively) high static pressure and CFM. Even with that said you will get significantly differing performance in differing environments, primarily humidity and atmospheric pressure. So all fans on the market, regardless of their use, are a compromise based on how the engineers feel like they can best accomplish a particular task at a particular budget. A perfect, one stop shop fan, will never exist.

[eBiz]

i honestly think the current fan designs are actually pretty much good for a long time. 

also, speaking of fans, whats your opinion of noise level? 

you care? or are you a silence person? 

 

i personally would rather have 2 200mm fans running at a low RPM for each intake side, and exauhst. just be whatever came with the case. x'D (none if thats the CASE... HAH! jokes.... ........................... im dead inside) 

 

 

 

speaking of 200mm. 

after a certian size increase/decrease, any one design will stop being optimal.

 

 

I wouldn't say I’m a silent person but have much respect for "silent" systems. My PC is in my bedroom but the TV is always on and the heat/air conditioning running so the background noise drowns out the noise of the fans. The build I’m working on now uses the Cooler Master Jet Flo fans which are 120mm and 95cfm. They are quite loud at the max speed but I will probably keep them at around 1000rpm.

 

I have experience with inline fans and I can agree that going bigger is always better when it comes down to moving air and noise levels. Yeah 200mm fans set up like that would provide awesome airflow and low noise. It's too bad larger fan sizes are not as popular as smaller options.