Best 120x120x25mm fan that can deliver 70 CFM???

[SUBMAN1]

Update: Still messing with my new sys. The sys as a whole has amazing frame rates in games, but the PSU is a little noisier than I originally anticipated. I am at the point where I think I am going to pull it apart and mod it.

Researching it, there is an ADDA fan in this thing that puts out 85 CFM @ 39.1 dba @ max speed of 2200 RPM. This is a little too loud for my blood, even though it isn't terrible. The box on the Silverstone states 24 dba minimum but at lowest speed it is more like 30 dba before ramping up to the 39.1 dba at the max speed of the fan (So where did they get the 24 dba number from? Advertising gone wrong again)

So the question is, who makes a 120mm x 120mm x 25 mm fan that delivers about 67-70 CFM (I want to stay within 80% of the CFM of the original ADDA that shipped in the Silverstone PSU) and is relatively quiet? I anticipate this will be somewhere around 1600 to 1800 RPM and the max db output should be around 30 dba. This also means that the normal op of the PSU should have a db output of somewhere around the high teens to mid 20's.

I've found a company called Globe that makes one in the range I am looking for, but I can't find where they are sold!!! Ahhhhh! Anyway, any help you guys can offer would be appreciated.

Thanks,

-S

[jumpy]

I have a couple of DELTA 120 x 120 x 38mm fans going spare
from the blurb:

Welcome to 190 cubic feet of wholesome goodness. It sure "feels" like it too. The FFB1212EHE has "Server Use Only" written all over it. If you do decide to strap this jet engine in a desktop PC, be sure to apply a second sheet of Dynomat to save your ears.

Specifications: 120x120x38mm, -->190.00<-- CFM @ 4000 RPM, 59.0 dBA, 24.00 watts, 2.00 amps, 12v DC, 3+4 pin Molex connectors.

Do not use the Sidewinder Rheostat with this fan. Also note the power requirements of the FFB1212EHE, there is a 3.00 amp startup requirement too.

Go here there's loads of fans/water cooling/heatsinks etc to choose from. Pretty decent kit too, if a little to the extreme end of the scale at times hehe ...190cfm lmao what was I thinking?!


ps. if you get anything like one of those 190cfm monsters, keep yer piggies well away when it's spinning, else it'll have 'em off!

[SUBMAN1]

Originally Posted by jumpy

I have a couple of DELTA 120 x 120 x 38mm fans going spare
from the blurb:

Go here there's loads of fans/water cooling/heatsinks etc to choose from. Pretty decent kit too, if a little to the extreme end of the scale at times hehe ...190cfm lmao what was I thinking?!


ps. if you get anything like one of those 190cfm monsters, keep yer piggies well away when it's spinning, else it'll have 'em off!

What were you thinking? :rotfl: Those Deltas move air but wow! 59 dba!

My last system you could not hear unless you put your ear right next to it, but the new one is just noticable is all. I would like to make a silent system out of it but I have already given in to the fact that my power draw is so high with dual core CPU and x1900 XTX (soon to be 2 XTX's!) that the best I can hope for is relatively quiet.

Those Delta's though - WHIIIRRRRRRRRRRR! That has got to drive you nuts!

-S

[Skybird]

In the 120 departement, the item by Rheinmetall does a significant job in silencing complaints about too hot temperatures.

[SUBMAN1]

Originally Posted by Skybird

In the 120 departement, the item by Rheinmetall does a significant job in silencing complaints about too hot temperatures.

Where I am going is near silent and still able to move some CFM.

I can't find these guys that you mention. Do you have a link?

-S

[Skybird]

Sorry, I was just pulling your leg. Try here:

http://www.fprado.com/armorsite/leo2.htm
http://www.military.com/soldiertech/...rd2A6,,00.html

[TteFAboB]

I was going to make a joke, asking if that's the company that made Hitler's suicide pistol, since they are specialized in silencing complaints about too hot temperatures.

But, now the timing is gone.

[SUBMAN1]

Originally Posted by Skybird

Sorry, I was just pulling your leg. Try here:

http://www.fprado.com/armorsite/leo2.htm
http://www.military.com/soldiertech/...rd2A6,,00.html

Hahahaha!

Just looking at that Leapard however it would seem the designers made it capable of dishing it out but surely not taking it. That thing has straight sides! No way to deflect an incoming round properly, even with reactive armor!

The Leopard 2 is better and the designers took those ideas into account, but they screwed up again and made what looks like shot traps! Nice tank, but vulnerable to return fire is all I have to say.

-S

[Skybird]

I severly doubt that dedicated anti-tank-rounds, especially SABOT, do "bounce off". It's more likely that the armour is meant to be penetrated, and the shot then get stuck. I once wrongly assumed myself, looking at the wedge of the turret's front of the new Leo2-A5 and A6 series, that the downside of the wedge almost would funnel any incoming frontal shot towards the ring between turret and hull where tanks are said to be vulnerable. But insiders and tankers told me that such ammunition is very unlikely just to bounce off, no matter at what angle it would hit the armor.

Germans know a thing or two about constructing fully competitive tanks I would think the engineers have their reasons why they built the modern Leos the way they are.
I should know. I sim with Steel Beasts Pro!

[SUBMAN1]

Originally Posted by Skybird

I severly doubt that dedicated anti-tank-rounds, especially SABOT, do "bounce off". It's more likely that the armour is meant to be penetrated, and the shot then get stuck. I once wrongly assumed myself, looking at the wedge of the turret's front of the new Leo2-A5 and A6 series, that the downside of the wedge almost would funnel any incoming frontal shot towards the ring between turret and hull where tanks are said to be vulnerable. But insiders and tankers told me that such ammunition is very unlikely just to bounce off, no matter at what angle it would hit the armor.

Germans know a thing or two about constructing fully competitive tanks I would think the engineers have their reasons why they built the modern Leos the way they are.
I should know. I sim with Steel Beasts Pro!

I don't agree with that assesment. Point blank maybe not, but at range, some angles with definitely help you. The Germans knew this best in WWII by the way!

Your simple answer to this question to show that angles help you is to simply look at the advances in design between a Leopard 1 and 2. The 2 has big improvements in angles for the very reason of shot deflection and it is very apparent across the entire tank - something sorely lacking on the 1st rev. Maybe they figure that the size of the tank made it a non factor if it got hit? Dunno.

Another example - take a T-90 or American Abrahms. They didn't make those angles for good looks!

-S

[Skybird]

that is because of very different kind of armour. i am no specialist for that, but I do know that steel armour, composite armour, chobham armour and what they all have are materials or clusters of materials that cannot be worked on all the same way. Where you can bend steel, you can't do that with certain composite armours, which comes in flat plates - this is why the russian tanks have bubble-turrets, while Abrams, Leo2 and Challenger have more squared surfaces (its also about size, design and components inside the tanks). The wedge at the front of the Leo2A5 for example,. which is new compoared to the A4 - we even do not know what it is, it is top secret. could be massive armour. Could reactive armour. could be hollow. Could be a bluff. I asked for that detail, but people from the Bundeswehr did not answer that and actively refused to do so. Also, the penetration power of projectiles from WWII and the present should,not be compared. In WWII, tank gun-projectiles bounced off hulls eventually, leaving a dent or a bump. If you look at todays armour, where a SABOT or even an uranium poenetrator hit, you see the material immediately penetrating, leaving star-shaped scratches if they were stopped by the armour, leaving a dead tank when they went through.So again, I have gotten confirmation that SABOT rounds do not that easily bounce off modern armour, but tend to heavily react with the surface. A SABOT penetratoris no giant bullet like they used in Napoleon'S times, it is a dart. Where the needle hits, it tries to pierce in. If you want to know more detaisl about that - I am no expert and can only rerpated what has been told to me - you need to visit the Steel Beast forum: lots of still active or ex tankers both from Abrams and Leo crews there that can answer your question with more expertise than I can. Concerning small and medium callibre fire and explosive warheads it maybe is like you say. SSnake (ex-Leo2-tanker) once said the riccocheting rounds that can be seen in Steel Beasts when a shot hits the ground at a shallow angle, or armour, actually are not meant to be the tank cannon rounds themsleves, but just sparkes and splitters. The rounds themselves, he said actually do not reflect off the ground or the armour, but penetrate more or less, always. I also was told that the wedge at the front of the Leo2A5-turret does not reflect rounds from tank cannons. I quote that &quot;as is&quot;.http://www.steelbeasts.com/modules.p...f0cc271e8b21Do not compare Leo2 and Leo 1. Leo-1 was a heavy-class turret put on top of a medium-class chassis, giving it firepower and mobility/agility at the price of armour. Speed was considered to be a priority in those days of newly introduced AT-missiles that at that time defeated most armour there was. the prsent generation of MBTs are all heavy-class equipment: chassis, turret, and gun. Nevertheless they do not suffer in speed, acceleration and agility, which tells volumes on the developement in engine technology, traction, and tracks. Since the tactics have changed with the shift from M60/Lep1/T72 to M1/Leo2/T80/90 as well, one should not compare these generations to each other. Try Steel Beasts, and get yourself into an old Leo1. You do not stand a single chance to survive the first round that hits you full, even if the shot hits the frontal turret. It is different in the Leo2 A4, and again slightly diffrent in the A5. I also start to get a feeling for the M1 now (but it lags behind in ergonomics, especially for the commander).One wants to assume that the models that are used for these vehicles in the sim are not totally off target due to it's professional target audience.
Hope that Neals fixes the messed up Return-buttons and plenty of
, / and missing text formatting soon.

[Skybird]

Is it only me having problems with text formatting, giving links, and printing quotation marks? Also, editing existing posts is a pain, formatting is totally messed up.

[TteFAboB]

Good, an opportunity for another joke, this time with timing:

And here I was, thinking you typed that hole thing in one go, with the compulsion of one who seeks to share his knowledge, but at the same time finds it all too obvious and boring to polish and make the message appealing to the eye, or ears.

[SUBMAN1]

Originally Posted by Skybird

that is because of very different kind of armour. i am no specialist for that, but I do know that steel armour, composite armour, chobham armour and what they all have are materials or clusters of materials that cannot be worked on all the same way. Where you can bend steel, you can't do that with certain composite armours, which comes in flat plates - this is why the russian tanks have bubble-turrets, while Abrams, Leo2 and Challenger have more squared surfaces (its also about size, design and components inside the tanks). The wedge at the front of the Leo2A5 for example,. which is new compoared to the A4 - we even do not know what it is, it is top secret. could be massive armour. Could reactive armour. could be hollow. Could be a bluff. I asked for that detail, but people from the Bundeswehr did not answer that and actively refused to do so. Also, the penetration power of projectiles from WWII and the present should,not be compared. In WWII, tank gun-projectiles bounced off hulls eventually, leaving a dent or a bump. If you look at todays armour, where a SABOT or even an uranium poenetrator hit, you see the material immediately penetrating, leaving star-shaped scratches if they were stopped by the armour, leaving a dead tank when they went through.So again, I have gotten confirmation that SABOT rounds do not that easily bounce off modern armour, but tend to heavily react with the surface. A SABOT penetratoris no giant bullet like they used in Napoleon'S times, it is a dart. Where the needle hits, it tries to pierce in. If you want to know more detaisl about that - I am no expert and can only rerpated what has been told to me - you need to visit the Steel Beast forum: lots of still active or ex tankers both from Abrams and Leo crews there that can answer your question with more expertise than I can. Concerning small and medium callibre fire and explosive warheads it maybe is like you say. SSnake (ex-Leo2-tanker) once said the riccocheting rounds that can be seen in Steel Beasts when a shot hits the ground at a shallow angle, or armour, actually are not meant to be the tank cannon rounds themsleves, but just sparkes and splitters. The rounds themselves, he said actually do not reflect off the ground or the armour, but penetrate more or less, always. I also was told that the wedge at the front of the Leo2A5-turret does not reflect rounds from tank cannons. I quote that &quot;as is&quot;.http://www.steelbeasts.com/modules.p...f0cc271e8b21Do not compare Leo2 and Leo 1. Leo-1 was a heavy-class turret put on top of a medium-class chassis, giving it firepower and mobility/agility at the price of armour. Speed was considered to be a priority in those days of newly introduced AT-missiles that at that time defeated most armour there was. the prsent generation of MBTs are all heavy-class equipment: chassis, turret, and gun. Nevertheless they do not suffer in speed, acceleration and agility, which tells volumes on the developement in engine technology, traction, and tracks. Since the tactics have changed with the shift from M60/Lep1/T72 to M1/Leo2/T80/90 as well, one should not compare these generations to each other. Try Steel Beasts, and get yourself into an old Leo1. You do not stand a single chance to survive the first round that hits you full, even if the shot hits the frontal turret. It is different in the Leo2 A4, and again slightly diffrent in the A5. I also start to get a feeling for the M1 now (but it lags behind in ergonomics, especially for the commander).One wants to assume that the models that are used for these vehicles in the sim are not totally off target due to it's professional target audience.
Hope that Neals fixes the messed up Return-buttons and plenty of
, / and missing text formatting soon.

Yeah - You make some valid points but the shot defelction part is still a major catagoy in MBT design, but maybe not Medium tank design. The LEo2 is definetly more survivable just by looking at it - it has way better angles to it. The Leo1 just looks like a barn door waiting to be hit!

All Sabot rounds fired from American tanks by the way are made of depleted uranium. Also, shot deflection of a sabot round was a major considration upon the turret design of the XM1 prototype. Here are some notes from that project. I'll add some sabot vs chobam vs angle here after breakfast.

I'm thinking 2 eggs cooked in butter with a lid, some patato cubes + onions and peppers cooked in extra virgin olive oil (Italian) and sprikled with sea salt, Italian sasauge patty, Tazo Zen green tea, and a peice of French bread toast sounds just about right. I'm making myself hungry! I'll be back. :p

-S


Chapter I.3. -- Target Description Methods (*DRAFT*)

By Michael John Muuss , U. S. Army Research Laboratory.
Decomposing the Task of Vulnerability Analysis


The vulnerability of a target to a given threat munition can be thought of as a synthesis of its vulnerabilities over the space of all given attack vectors and velocities. In order to extend the notion of vulnerability into the domain of survivability each individual vulnerability must be weighted by some measure of the probability that a munition will arrive on that attack vector, according to this formula: V(target) = SIGMAi=1..n { V(pi) * w(pi) } where

• V() is a function which returns an abstract measure of the vulnerability for a given attack path,
• pi is the ith specific attack path,
• w() is the weighting function ranging from 0..1 which describes the likelihood that an opponent will be able to attack on a given path, and
• n is the number of attack paths being considered.

The weighting function w() takes into account the natural geometry of the target and it's relationship with the ground that it sits on, any countermeasures which might make the target more difficult to sight and acquire from certain directions or under certain conditions, and tactical considerations such as the use of cover and defilade . For example, a design with a robust turret but a weak underbelly would be much more valuable to the Army for tank-to-tank combat than a design with a weak turret and a robust underbelly. In this case, the weighting function expresses the fact that it is unlikely that a tank-fired munition will approach the target from below.

The task of evaluating the function V() can be broken into two parts. First, it is necessary to determine the geometry at the point where the threat munition impacts the target, and second, it is necessary to compute the response of the materials of both threat and target to their high-velocity collision. This chapter addresses only the geometric concerns; subsequent chapters will detail the modeling of the material response, and the process of synthesizing the individual shot results into an overall presentation that is meaningful to design engineers and program managers.

[SUBMAN1]

What is with the text limitation? 7500 Characters? Wow!

Here is more to that article, but it seems we are limited on how big a post we can add.

The Shotline as a Model of Projectile Travel


While it has long been understood that projectiles do not fly through the atmosphere in a straight line, their trajectories over short intervals (several meters or less) can be safely approximated by a straight line-segment. This approximation is particularly apt for tank ammunition, which is typically fired at low gun elevations and high velocities. Thus, the attack path pi can be safely described as a mathematical ray, or directed line, emmanating from a starting point P in three-space and proceeding along a given direction vector D. As long as the actual trajectory of the projectile and the matehmatical ray are coincident in the vicinity of the target, the approximation remains valid.
The ray may be expressed in parametric form, such that every point X on the ray has a one-to-one correspondence with some value of the scalar parameter t: X = P + t * Dwhere X, P, and D are 3-tuples, and t is a scalar. t is thus a measure of the distance that the projectile has traveled along the ray.

Each component of the target, or region, may be considered to partition the shotline into intervals along the ray. The start of each interval occurs where the ray enters the component, and the interval ends where the ray exits the component. If two components adjoin one another, a second interval may immediately follow the first.
For each interval, at a minimum it is necessary to be able to provide the parametric distances corresponding to the entry and exit points, and the surface normal at both the entry and exit points. From those values it is possible to compute the line-of-sight thickness through the component, the 3-space coordinates of the entry and exit points, and the obliquity angle of the shot. These are essential inputs into the penetration equations.
When a penetrator passes through an armor plate, it's trajectory is usually deflected somewhat off it's initial course. For the most accurate results, it is necessary to generate a new shotline each time one layer of armor is perforated.