Easiest way to test cooling ducts?

[M_a_t_t]

Would it be reasonable to test ducts without the car? I have an idea for some cooling ducts for my mercury, but I think it would be easier to make the duct and test with it in a fixture ahead of the car rather than tearing apart the current cooling system to keep playing with it for the different tests.

If the inlet/outlet are in fixed positions would that eliminate not having the car surrounding the duct?

The last question is slightly off topic from the thread title, can you calculate (theoretically or through testing) how much radiator/cooling you need? I am hoping to get my swap (metro engine in the mercury) done this summer and I have a few options for the cooling setup. Use the mercury's radiator, use the metro's radiator, or use something else.

[aerohead]

Originally Posted by M_a_t_t

Would it be reasonable to test ducts without the car? I have an idea for some cooling ducts for my mercury, but I think it would be easier to make the duct and test with it in a fixture ahead of the car rather than tearing apart the current cooling system to keep playing with it for the different tests.

If the inlet/outlet are in fixed positions would that eliminate not having the car surrounding the duct?

The last question is slightly off topic from the thread title, can you calculate (theoretically or through testing) how much radiator/cooling you need? I am hoping to get my swap (metro engine in the mercury) done this summer and I have a few options for the cooling setup. Use the mercury's radiator, use the metro's radiator, or use something else.

1) it's unlikely that you can achieve the actual dynamic pressure anywhere else than in the actual location of the inlet at the nose. You'd have an unknown quantity out ahead of the car.
2) the inlet/outlet is a 'system' reliant upon all dynamics present in the eventual 'installed' position. Again, I know of no way you could accurately simulate these conditions.
3) you need your design heat flux, then sizing will come from the heat exchanger's manufacturer recommendations, at conditions which match Furnace Creek, Death Valley, California, full sun, summer peak conditions, car parked, idling, maximum passenger load, all accessories 'ON.'

[JulianEdgar]

Originally Posted by aerohead

1) it's unlikely that you can achieve the actual dynamic pressure anywhere else than in the actual location of the inlet at the nose. You'd have an unknown quantity out ahead of the car.
2) the inlet/outlet is a 'system' reliant upon all dynamics present in the eventual 'installed' position. Again, I know of no way you could accurately simulate these conditions.

Yes I agree.

[freebeard]

M_a_t_t, I hope you realize what you've accomplished here.

[JulianEdgar]

Originally Posted by freebeard

M_a_t_t, I hope you realize what you've accomplished here.

Not everything that Aerohead writes here is wrong. Just the vast majority.

[Autobahnschleicher]

Wait, you guys can agree on something?

[JulianEdgar]

Originally Posted by Autobahnschleicher

Wait, you guys can agree on something?

I never disagree with Aerohead just for the sake of it. I disagree because so much of what he posts is outright wrong, is misleading or is deceptive. On this occasion, the bit I quoted wasn’t any of these things.

[JulianEdgar]

But this part is typical Aerohead - completely unhelpful to the poster and misleading, in that this is not a suitable approach for an amateur.

Originally Posted by aerohead

3) you need your design heat flux, then sizing will come from the heat exchanger's manufacturer recommendations, at conditions which match Furnace Creek, Death Valley, California, full sun, summer peak conditions, car parked, idling, maximum passenger load, all accessories 'ON.'

[Xist]

Can't you two just get along?!

Is it me or is this a one-sided feud?

[aerohead]

Originally Posted by JulianEdgar

But this part is typical Aerohead - completely unhelpful to the poster and misleading, in that this is not a suitable approach for an amateur.

Well, I'd give myself at least an ' incompletely' unhelpful.
* I've no idea what a Mercury Tracer Trio is.
* I've no idea what the operational envelope of the proposed vehicle would be.
* Without the envelope there's no way to predict the road load.
* Without the road load there's no way to compute the required brake horsepower requirement.
* Without the brake horsepower requirement there'd be no way to come up with the heat flux, even with a BSFC map.
* Without the heat flux, we can't anticipate if any of the two original radiators would be adequate to dissipate it, or if the Metro water pump would be adequate for the necessary ( but unknown ) coolant flow rate.
* there's a heat transfer coefficient involved ( an unknown )
* will there be an air conditioning condenser coil upstream of the radiator, to add to its work?
* what is the difference in energy / distance / degree ratings? ( conductance capacity )
* are there options to coolant chemistry and chemical compatibility with existing components.
* ditch the mechanical water pump and go with a Messier electric, variable-speed pump with sensor and logic ?
I'd need some more data.