hornetball

iTrader: (4)

I thought the experiment was pretty good from a control/repeatability standpoint. The main temperatures measured were IC intake and outlet temperatrues. The geek in the group (guy running MATLAB) had a few extra thermocouples, so they stuck them in a few other places. The ones you mention weren't material to the results.

Test was pretty much setup to maximize radiation results. Low CFM heated air source (heat gun) and an interior room much colder than the heat gun outlet temperature. Not particularly applicable to a real automotive environment (i.e., in the presence of a hot radiator), but I was still surprised by the numbers they achieved. I wouldn't bother to paint an intercooler black based upon this, but I liked the video. Sorry Brain, I guess I'm unwashed -- or maybe I'm hot for Aussies -- who knows?

Braineack

iTrader: (62)

if you want to heatsoak on IC, put it in an oven and make it so the core is exactly the same temp for both tests, the way they did it left a lot of margin for error. I think the heatsoak test was a complete waste of time/video/amazement for the tester. case and point: the painted IC exhibited "greater" efficiency without airflow.

hornetball

iTrader: (4)

Did we watch the same video? They ran the heat gun until a stabilized temp was achieved from the thermistors. Stabilized inlet temps were the same (or within a margin of error) for all tests.

No Airflow Results (Radiation and Convection):
Shiny: Delta T = 38C (basically convection only)
Black: Delta T = 77C (radiation and convection)

With Airflow Results (Conduction):
Shiny: Delta T = 100C
Black: Delta T = 97C

The above clearly shows that black paint increases emissivity over a shiny mirror finish -- which is expected -- just didn't expect this much. It also shows that black paint has a slight insulating effect. In both cases, the efficiency is much better with airflow.

???

chiods

I feel it safe to say mighty car mods guys arent scientists and any time they attempt to collect data without using tbe scientific method that it should be for entertainment purposes only.

Leafy

iTrader: (1)

But they had their tame mechatronics engineer there to perform the data collection.

y8s

iTrader: (8)

shiny metals are pretty much the worst radiating surface ever.

Braineack

iTrader: (62)

No, they ran the heat gun until the "lines on the graph are steady". You're assuming a lot.

Heat soaking an IC would suggest the IC is so hot, it can no longer cool the air that's passing through it as well. If they reached heat soak, then they should be reaching the point where the difference between the inlet and outlet temps starts to become smaller, not "steady". What they did was reach a sort of equilibrium point between the intercooler and ambient.

Testing without airflow did nothing but suggest that shiny metal doesn't emit Infrared (see how hairdryers work) as well as painted metal. And since we all know that black flat paint absorbs heat better than shiney metal, the test results were "mindblowning".

They could have tested the same with another color to disprove black in general, im sure red or even white flat paint would have similar results in this test. Or using glossy paint would have even altered the results. Even just scotchbriting the aluminum so it wasn't shiney might have a similar effect, or at least a different result to test.

All this test did was just confirm a proven common knowledge about shiney metal vs. flat paints.

and I still doubt the test method between these two, it would have been nicer to simply know the: ambient, inlet, and outlet temps; not just the delta.

But that's not what was important, when they finally added airflow, the difference in the delta was a 3% difference, so essentially the same, since they were no longer testing infrared, and the actual effectiveness of the IC. This was the only thing we really cared about and they put little emphasis on it. The tester went as far as talking about the mean value between 4 temp readings, but didn't give the number for the painted one. What it did at least prove is that the "thermal barrier" everyone is worried about is complete crap.

Leafy

iTrader: (1)

Brain. no. They're exactly right with heat soak. The condition you're looking for doesnt happen. Heat soak is when you hit steady state, its when the metal of the intercooler has stopped absorbing the hear energy and is now only removing heat from the air charge by transferring it to the environment outside of the intercooler. The only way your way happens is if the ability of the intercooler to transfer heat is terrible, or changes with temperature of the material the intercooler is made of.

Braineack

iTrader: (62)

oh whatever, it was still dumb.

18psi

iTrader: (76)

I was devastated that the plots were not upside-down

hornetball

iTrader: (4)

We're back in agreement then. To me:

1. Experiment was an interesting demonstration of radiative heat transfer and the difference between absorption/emissivity and reflection. Applicable to our heat shielding.
2. Other than the air flow case where both IC's performed the same, the experiment really is not applicable to the automotive environment.

Keep the stuff around your manifold/turbo/DP shiny dudes!

stratosteve

iTrader: (1)

(worthy of it's own thread, but totally related)

This thread along with the EFR fail thread have given me an idea. What if that EFR was using e cool? Would it redefine physics? Would we turn the corner and begin our descent into low low IAT's?

Ladies and gentlemen, today I introduce P cool........





Clearly that is black paint being injected into a DTB. I haven't come up with a way to control the spray just yet. I am thinking another pcpro? Combine the results from this thread and a proven liquid intercooler and profit.

18psi

iTrader: (76)

but does it require extra tuning?

stratosteve

iTrader: (1)

Need to come up with a better attachment other than gravity. Too soon to know.

Leafy

iTrader: (1)

gorilla tape.

stratosteve

iTrader: (1)

Can't wait till all that heat emissivityzes right on out the tailpipe

x_25

Woops... I am gonna have all that and a supercharger....

hi_im_sean

iTrader: (3)