Overlaying a Car On the Template

[cleanspeed1]

So is the goal to make vehicle conform totally to the template shape? Some of the body shapes require a boattail that goes waaaaaaayyyy back, and may not be everyday practical or aesthetically pleasing.

I am an aero virgin, please be gentle.

This is what happens when you play with engines for the better part of your life.

[Frank Lee]

So is the goal to make vehicle conform totally to the template shape?

Depends on what you want to use the vehicle for, and how much cutting and hacking you are up for.

[cleanspeed1]

I mean for maximum effect, the cutting and hacking is just the price of admission.

[jtbo]

Originally Posted by cleanspeed1

I mean for maximum effect, the cutting and hacking is just the price of admission.

For maximum effect, you must of course go with maximum shape, ahem full shape that is.

However most of the effect comes from first part, there was recent thread about that also, can't remember how much it was, but it was not much that you would need to get most of the effect.

I have now 50cm kamm behind my wagon, that is bit under 2 foot as 66cm is 2 foot from my memory.

Even it is no larger than that, it still seem to be very efficient as coast down testing did show 24% improvement for air resistance, but there is some error margin, so I like to think it being 'only' 18% of improvement.

I think that is really a lot, but it coasts down really well and even wind noise is lot less, so I'm thinking that it must be true that first parts of template makes most effect.

[cleanspeed1]

Originally Posted by jtbo

For maximum effect, you must of course go with maximum shape, ahem full shape that is.

However most of the effect comes from first part, there was recent thread about that also, can't remember how much it was, but it was not much that you would need to get most of the effect.

I have now 50cm kamm behind my wagon, that is bit under 2 foot as 66cm is 2 foot from my memory.

Even it is no larger than that, it still seem to be very efficient as coast down testing did show 24% improvement for air resistance, but there is some error margin, so I like to think it being 'only' 18% of improvement.

I think that is really a lot, but it coasts down really well and even wind noise is lot less, so I'm thinking that it must be true that first parts of template makes most effect.

So that we are clear, you are talking about the front of the template vehicle, correct?

[Frank Lee]

NO!!! First part of boattail as used on a kamm.

[jtbo]

Originally Posted by Frank Lee

NO!!! First part of boattail as used on a kamm.

This is exactly right.

Front part is not meaningless, but it is rather not important, always focus the rear and there is most of the gains.

Sure there are few things at front too, but most is rear and maybe underside, rest I would leave for when one would like to get even more, but that is just my idea of aero.

[cleanspeed1]

OK, got it.

[cleanspeed1]

Originally Posted by Frank Lee

NO!!! First part of boattail as used on a kamm.

Haven't had coffee yet, Frank?

[Frank Lee]

Haven't been to sleep yet. Terrible insomnia.