The Wind Tunnel: A Tool for System Designers

Completely runs the fan at a speed, measures the pressure at this location and then plots that point here. This point is not useful to system designers other than to just have some way of comparing the system. Um because this doesn't occur in real life if you have zero flow it's not doing any good for you at all. The wind tunnel begins by opening valves inside here and allowing some air to flow from first chamber into the second chamber and that reduces the static pressure and the flow increases.

So as that happens the next data point is here and then it opens up some more and here and here and here and it works its way all the way down until the pressure here equals atmospheric pressure and that is the zero resistance point or maximum flow which is the other spec that you see on the box. Which is also doesn't occur in reality because if you don't have any resistance there's nothing in the way of your fan right just in reality your system will be somewhere in between these points and you can plot a resistance curve for say like a radiator um and that curve will go up in this direction and where those two curves intersect is the actual pressure and flow that you will receive when you combine those elements in a system.

That's actually the really useful information. Each one of these lines is a different speed, this 100% 90% 80% and so on all the way down to 20%. The horizontal lines here are the fans RPM excuse me these are the fans RPM and so um this blue line corresponds with this orange kind of peach colored line this green line with this purple line Etc. It shows the RPMs over here and as you can see this fan is very stable regardless of the amount of resistance it receives it doesn't really fluctuate and speed very much and that so that's the report you get after using it mechanically uh let's I guess walk from this end to that end what's going on inside of the Wind Tunnel.

So let's back up just a smidge um here is the plate where we Mount the device to be tested a fan or a radiator I've even hooked up whole cases to this thing um and measured flow resistance in cases um this ring right here is attached to four pressure Taps. This is the static pressure sensor it measures this in relationship to atmospheric pressure outside of the room inside here there are several screens those are to diffuse the flow so that the air Flows at the same speed through the entire diameter of the Wind Tunnel that's necessary for the calculations because the math makes certain assumptions about the diameter of the wind tunnel and how fast the air is Flowing.

These two pressure Taps here are differential they're measured against each other this is the high side pressure this is the low side pressure um in this plate here in the middle there's a series of valves that start out about half an inch in diameter and go all the way up to several inches in diameter and it can open one or more valves depending on the type of test that it's doing. This chart here actually shows the smallest valve is 8 mm in diameter and the largest is 42 but in this 32 plus 42 and all and it tells you the CFM range for whatever combination of valves you have open at that time.

So when measuring the differential pressure across here and knowing the exact diameter of the valve it knows the parametric pressure and it knows the temperature and humidity of the air calculates the air density can then calculate the exact CFM flowing through the system um this chamber has a couple more screens in it to equalize the flow and then that tube goes out to a big fan right there that's the counter blower. Um this is necessary because the wind tunnel itself has significant airflow resistance and so it actually pulls a vacuum in this chamber in order to get the flow that it needs to achieve in the first chamber.

Um this chamber often operates below atmospheric pressure that's that's normal so in order to get to this chamber this point here to equal atmospheric pressure this chamber here has to be significantly below atmospheric pressure very cool then uh wrapping it all back to the end product. This is the the numbers that come up on the box at the end of the day come up in the new XC sheet comes from something like this I guess that's correct all the published specifications for all of our fat products come out of this machine um.

This machine costs about $75,000 and once a year I fly a guy out from Taiwan to come calibrate it um his calibration reports are nist trable and you can actually go up on the National Institute of Standards website and look it up um so I am very confident in the numbers and performance data that comes out of this machine.

"WEBVTTKind: captionsLanguage: enhey everyone we are here in the Corsair validation facilities I'm joined by Bobby kinst and Bobby what what do you do here what do you know about this stuff so I'm the thermal engineer here at Corsair I design all the cooling systems that includes fans liquid coolers heat sinks I consult airf flow anything that involves heat transfer or Cooling and the first machine I or setup I want to talk about is a thermal chamber uh so in this room which you'll see some of this in a moment but there's a wind tunnel for fan testing thermal chamber there's a chroma chroma setup for power supply testing with this uh let's let's just talk about the very basics of a thermal chamber so we've we've already said why you would want one in previous content but what are some of the different types of Chambers available like humidity temperature control okay so basically a thermal chamber is a heater or refrigerator in a highly insulated box so you set the temperature that you want on here and that can be a high temperature or a low temperature for whatever you're trying to test for and then it maintains that temperature some of them are programmable so that they can go through different temperature ranges these are basic temperature only Chambers but they also make humidity control Chambers some Chambers with liquid nitrogen for extreme cooling um some Chambers have shock and vibration tables in them for extreme vibration um that sort of thing um some have dry air injection so they can get to extremely low humidities or extreme temperature conditions um but for this industry temperature only seems to do the job just fine so in in what use case would you want uh humidity control for a thermal chamber if you were building products for a very highly humid environment like southeast Asia or you concerned about corrosion or delamination of your circuit boards for example then you would definitely want a humidity chamber um we do that kind of testing just not at this facility and we were talking just before shooting this video about uh humidity and how it impacts the heat capacity of the air so let's let's run through that that again for viewers sure um the more humidity is in the air the more heat the air can carry per unit of volume and that's because the air density increases so if you have a cubic foot of air at 20% humidity you're going to be able to carry a little bit less heat than a cubic foot of air at 80% humidity um so in that regard even though high humidity is very uncomfortable for us people that actually helps the computer carry heat better got it and this chamber here what what are uh I guess you test your cool cases in here what's the how do you deploy the chamber yeah we put in these wire shelves that are up here on top we can put a computer in here or just a power supply or just a cooler I can show you in the next chamber over we have a setup for testing processors we use a thing called a thermal test vehicle um which is an actual processor made by Intel um and it goes into an actual processor socket and has the same mounting as a heat sink you can attach a heat syn to it and then the wires come out of this thing goes to a power supply and you turn it up and it's a heater it's just a heater chip it doesn't doesn't actually compute right and then I can say I want 100 watts and then I can measure the temperature of the top of the die and it's temperature differential and then calculate how well the heat sink is working right so you can basically simulate a CPU uh because you can set the the wattage I guess so you simulate the higher TDP or lower TDP chips exactly I can dial in whatever power level I want right so that's pretty cool Okay so we've moved camera shot uh this is what we were just talking about so can you walk me through this all right this is an Intel thermal test vehicle for socket 2011 processor um it has a socket 2011 sized CPU device here um has a heater built into it the heater is the same size as the microprocessor in real life so it has the same heat flux per square millimeter as a real processor um this little line right here on top is a thermocouple that's embedded in there that allows me to measure the temperature at the very top of the package I can measure the temperature of the heat sink or I can measure the temperature of the ambient and then calculate the effectiveness of the heat sink and its performance in degrees C per watt I know how much power I put into it by running it with my DC power supply over here so I know exactly how much power's going in know exactly how much Heat's coming out and then I can have a very good idea on the performance of the thermal system uh so for this programmable DC power supply what can you tell me so as the name suggests it's a DC power supply I can set it to Output any voltage that I want um it has current limits for safety um but what makes this very special isn't just that it's programmable is it has highly accurate metering built into it so so I can say you know we've got four digits of precision on voltage and and current um so I have a very very good idea how much power is going into it it cares so much that it actually measures the voltage at the TTV not at the terminals here so it compensates for the voltage drop Through the Wire oh cool okay so now we are in front of the Wind Tunnel let's start with the report that you have on screen what's what are we looking at here okay what we're looking at here is the actual wind tunnel report for the Corsair ml120 blue lud fan um these lines here each line represents the pressure and flow um at a particular Point um so this axis is pressure this axis is flow um the maximum pressure spec that you see on the Box is always measured at zero flow the wind tunnel closes itself completely runs the fan at a speed measures the pressure at this location and then plots that point here this point is not useful to system designers other than to just have some way of comparing the system um because this doesn't occur in real life if you have zero flow it's not doing any good for you at all the wind tunnel Begins by opening valves inside here and allowing some air to flow from first chamber into the second chamber and that reduces the static pressure and the flow increases so as that happens the next data point is here and then it opens up some more and here and here and here and it works its way all the way down until the pressure here equals atmospheric pressure and that is the zero resistance point or maximum flow which is the other spec that you see on the box which is also doesn't occur in reality because if you don't have any resistance there's nothing in the way of your fan right just in reality your system will be somewhere in between these points and you can plot a resistance curve for say like a radiator um and that curve will go up in this direction and where those two curves intersect is the actual pressure and flow that you will receive when you combine those elements in a system that's actually the really useful information so each one of these lines is a different speed this 100% 90% 80% and so on all the way down to 20% the horizontal lines here are the fans RPM excuse me these are the fans RPM and so um this blue line corresponds with this orange kind of peach colored line this green line with this purple line Etc it shows the RPMs over here and as you can see this fan is very stable regardless of the amount of resistance it receives it doesn't really fluctuate and speed very much and that so that's the report you get after using it mechanically uh let's I guess walk from this end to that end what's going on inside of the Wind Tunnel so let's back up just a smidge um here is the plate where we Mount the device to be tested a fan or a radiator I've even hooked up whole cases to this thing um and measured flow resistance in cases um this ring right here is attached to four pressure Taps um this is the static pressure sensor it measures this in relationship to atmospheric pressure outside of the room inside here there are several screens those are to diffuse the flow so that the air Flows at the same speed through the entire diameter of the Wind Tunnel that's necessary for the calculations because the math makes certain assumptions about the diameter of the wind tunnel and how fast the air is Flowing these two pressure Taps here are differential they're measured against each other this is the high side pressure this is the low side pressure um in this plate here in the middle there's a series of valves that start out about half an inch in diameter and go all the way up to several inches in diameter and it can open one or more valves depending on the type of test that it's doing this chart here actually shows the smallest valve is 8 mm in diameter and the largest is 42 but in this 32 plus 42 and all and it tells you the CFM range for whatever combination of valves you have open at that time so when measuring the differential pressure across here and knowing the exact diameter of the valve it knows the parametric pressure and it knows the temperature and humidity of the air calculates the air density can then calculate the exact CFM flowing through the system um this chamber has a couple more screens in it to equalize the flow and then that tube goes out to a big fan right there that's the counter blower um this is necessary because the wind tunnel itself has significant airf flow resistance and so it actually pulls a vacuum in this chamber in order to get the flow that it needs to achieve in the first chamber um this chamber often operates below atmospheric pressure that's that's normal so in order to get to this chamber this point here to equal atmospheric pressure this chamber here has to be significantly below atmospheric pressure very cool then uh wrapping it all back to the end product this is the the numbers that come up on the box at the end of the day come up in the new XC sheet comes from something like this I guess that's correct all the published specifications for all of our fat products come out of this machine um this machine costs about $75,000 and once a year I fly a guy out from Taiwan to come calibrate it um his calibration reports are nist trable and you can actually go up on the National Institute of Standards website and look it up um so I am very confident in the numbers and performance data that comes out of this machine awesome so for more information as always Link in the description below we'll have an article with more information thank you Bobby for joining me we'll see you all next time forhey everyone we are here in the Corsair validation facilities I'm joined by Bobby kinst and Bobby what what do you do here what do you know about this stuff so I'm the thermal engineer here at Corsair I design all the cooling systems that includes fans liquid coolers heat sinks I consult airf flow anything that involves heat transfer or Cooling and the first machine I or setup I want to talk about is a thermal chamber uh so in this room which you'll see some of this in a moment but there's a wind tunnel for fan testing thermal chamber there's a chroma chroma setup for power supply testing with this uh let's let's just talk about the very basics of a thermal chamber so we've we've already said why you would want one in previous content but what are some of the different types of Chambers available like humidity temperature control okay so basically a thermal chamber is a heater or refrigerator in a highly insulated box so you set the temperature that you want on here and that can be a high temperature or a low temperature for whatever you're trying to test for and then it maintains that temperature some of them are programmable so that they can go through different temperature ranges these are basic temperature only Chambers but they also make humidity control Chambers some Chambers with liquid nitrogen for extreme cooling um some Chambers have shock and vibration tables in them for extreme vibration um that sort of thing um some have dry air injection so they can get to extremely low humidities or extreme temperature conditions um but for this industry temperature only seems to do the job just fine so in in what use case would you want uh humidity control for a thermal chamber if you were building products for a very highly humid environment like southeast Asia or you concerned about corrosion or delamination of your circuit boards for example then you would definitely want a humidity chamber um we do that kind of testing just not at this facility and we were talking just before shooting this video about uh humidity and how it impacts the heat capacity of the air so let's let's run through that that again for viewers sure um the more humidity is in the air the more heat the air can carry per unit of volume and that's because the air density increases so if you have a cubic foot of air at 20% humidity you're going to be able to carry a little bit less heat than a cubic foot of air at 80% humidity um so in that regard even though high humidity is very uncomfortable for us people that actually helps the computer carry heat better got it and this chamber here what what are uh I guess you test your cool cases in here what's the how do you deploy the chamber yeah we put in these wire shelves that are up here on top we can put a computer in here or just a power supply or just a cooler I can show you in the next chamber over we have a setup for testing processors we use a thing called a thermal test vehicle um which is an actual processor made by Intel um and it goes into an actual processor socket and has the same mounting as a heat sink you can attach a heat syn to it and then the wires come out of this thing goes to a power supply and you turn it up and it's a heater it's just a heater chip it doesn't doesn't actually compute right and then I can say I want 100 watts and then I can measure the temperature of the top of the die and it's temperature differential and then calculate how well the heat sink is working right so you can basically simulate a CPU uh because you can set the the wattage I guess so you simulate the higher TDP or lower TDP chips exactly I can dial in whatever power level I want right so that's pretty cool Okay so we've moved camera shot uh this is what we were just talking about so can you walk me through this all right this is an Intel thermal test vehicle for socket 2011 processor um it has a socket 2011 sized CPU device here um has a heater built into it the heater is the same size as the microprocessor in real life so it has the same heat flux per square millimeter as a real processor um this little line right here on top is a thermocouple that's embedded in there that allows me to measure the temperature at the very top of the package I can measure the temperature of the heat sink or I can measure the temperature of the ambient and then calculate the effectiveness of the heat sink and its performance in degrees C per watt I know how much power I put into it by running it with my DC power supply over here so I know exactly how much power's going in know exactly how much Heat's coming out and then I can have a very good idea on the performance of the thermal system uh so for this programmable DC power supply what can you tell me so as the name suggests it's a DC power supply I can set it to Output any voltage that I want um it has current limits for safety um but what makes this very special isn't just that it's programmable is it has highly accurate metering built into it so so I can say you know we've got four digits of precision on voltage and and current um so I have a very very good idea how much power is going into it it cares so much that it actually measures the voltage at the TTV not at the terminals here so it compensates for the voltage drop Through the Wire oh cool okay so now we are in front of the Wind Tunnel let's start with the report that you have on screen what's what are we looking at here okay what we're looking at here is the actual wind tunnel report for the Corsair ml120 blue lud fan um these lines here each line represents the pressure and flow um at a particular Point um so this axis is pressure this axis is flow um the maximum pressure spec that you see on the Box is always measured at zero flow the wind tunnel closes itself completely runs the fan at a speed measures the pressure at this location and then plots that point here this point is not useful to system designers other than to just have some way of comparing the system um because this doesn't occur in real life if you have zero flow it's not doing any good for you at all the wind tunnel Begins by opening valves inside here and allowing some air to flow from first chamber into the second chamber and that reduces the static pressure and the flow increases so as that happens the next data point is here and then it opens up some more and here and here and here and it works its way all the way down until the pressure here equals atmospheric pressure and that is the zero resistance point or maximum flow which is the other spec that you see on the box which is also doesn't occur in reality because if you don't have any resistance there's nothing in the way of your fan right just in reality your system will be somewhere in between these points and you can plot a resistance curve for say like a radiator um and that curve will go up in this direction and where those two curves intersect is the actual pressure and flow that you will receive when you combine those elements in a system that's actually the really useful information so each one of these lines is a different speed this 100% 90% 80% and so on all the way down to 20% the horizontal lines here are the fans RPM excuse me these are the fans RPM and so um this blue line corresponds with this orange kind of peach colored line this green line with this purple line Etc it shows the RPMs over here and as you can see this fan is very stable regardless of the amount of resistance it receives it doesn't really fluctuate and speed very much and that so that's the report you get after using it mechanically uh let's I guess walk from this end to that end what's going on inside of the Wind Tunnel so let's back up just a smidge um here is the plate where we Mount the device to be tested a fan or a radiator I've even hooked up whole cases to this thing um and measured flow resistance in cases um this ring right here is attached to four pressure Taps um this is the static pressure sensor it measures this in relationship to atmospheric pressure outside of the room inside here there are several screens those are to diffuse the flow so that the air Flows at the same speed through the entire diameter of the Wind Tunnel that's necessary for the calculations because the math makes certain assumptions about the diameter of the wind tunnel and how fast the air is Flowing these two pressure Taps here are differential they're measured against each other this is the high side pressure this is the low side pressure um in this plate here in the middle there's a series of valves that start out about half an inch in diameter and go all the way up to several inches in diameter and it can open one or more valves depending on the type of test that it's doing this chart here actually shows the smallest valve is 8 mm in diameter and the largest is 42 but in this 32 plus 42 and all and it tells you the CFM range for whatever combination of valves you have open at that time so when measuring the differential pressure across here and knowing the exact diameter of the valve it knows the parametric pressure and it knows the temperature and humidity of the air calculates the air density can then calculate the exact CFM flowing through the system um this chamber has a couple more screens in it to equalize the flow and then that tube goes out to a big fan right there that's the counter blower um this is necessary because the wind tunnel itself has significant airf flow resistance and so it actually pulls a vacuum in this chamber in order to get the flow that it needs to achieve in the first chamber um this chamber often operates below atmospheric pressure that's that's normal so in order to get to this chamber this point here to equal atmospheric pressure this chamber here has to be significantly below atmospheric pressure very cool then uh wrapping it all back to the end product this is the the numbers that come up on the box at the end of the day come up in the new XC sheet comes from something like this I guess that's correct all the published specifications for all of our fat products come out of this machine um this machine costs about $75,000 and once a year I fly a guy out from Taiwan to come calibrate it um his calibration reports are nist trable and you can actually go up on the National Institute of Standards website and look it up um so I am very confident in the numbers and performance data that comes out of this machine awesome so for more information as always Link in the description below we'll have an article with more information thank you Bobby for joining me we'll see you all next time for\n"