7 replies to this topic

[Nathan]

Correct me if Im wrong, but I believe Gold is one of the better heat conductors is it not? If so, is it possible to run Gold fillings/paeticles in a cooling system? This was just something I was thinking up and wondered if it would work.

[moog101]

I think particles in a cooling system is going to end in tears.

They are going to settle and block any and every thing in sight as soon as you turn off.....

Also the gold would just transfer it's heat to the medium it was in, unless you ran gold at an ultra low pressure so it was liquid sort of self defeating tho' as it would just boil very easily.

[blkirk]

Yes, gold is a good conductor of heat. However, it only conducts heat when it is a solid piece. Little particles in the coolant would only add weight to the car.

Also, coolant doesn't really need to conduct heat. It just needs to hold on to the heat while it gets pumped from the block to the radiator. The thermal capacity of the coolant is much more important than its conductivity. If the coolant has a higher thermal capacity, then it will not change temperature as rapidly as you add heat to it. It will stay cooler in the engine causing more heat to flow in and stay warmer in the radiator helping more heat to flow out.

Water has a thermal capacity roughly ten times higher than most metals. I'm sure a chemist somewhere has come up with something with a higher capacity than water.

[desmo]

I read somewhere that at room temps, diamond is the best known thermal conductor! Don't know where to go with that, just thought I'd throw it out there. Contribute your wedding rings to your favorite team please!

[blkirk]

I just couldn't resist. I had to look up the thermal conductivities of a few materials, and you're right desmo. Diamond is a great thermal conductor.

Material............Thermal Conductivity at 273K (W/cm-K)
Iron................0.835
Aluminum............2.36
Gold................3.18
Copper..............4.01
Silver..............4.28
Carbon
Type I, Diamond.....9.94
Type IIb, Diamond...15.2
Type IIa, Diamond...26.2

So, it looks like diamond type IIa is the thermal conductor of choice. I wonder if any of the teams have considered using diamond fins on their engines and going air-cooled. Carbon nanotubes are supposedly even better conductors of heat, but it will still be a number of years before even F1 teams can afford to use them in any significant quantities.

n.b. I didn't find anything explaining the differences in the three types of diamond.

[Ray Bell]

Most women tend to get hot when given the right kind of diamond, it's true....

[desmo]

Ray,

Let me welcome you back to the Tech Forum. I've really missed seeing you contribute here. I hope the move went as smoothly as those things ever do. I hate moving!

Kurt

[desmo]

Carbon nanotubes! I wondered when someone would come up with a good application for those. Can you imagine the surface area one could get into a tiny rad with those? Assuming of course that you could persuade coolant through them in any quantity.

Buckyballs!