sharp edges on tail

[D15r]

So most cars have rounded trailing edges . This we know isn't the best for low drag. As I've learnt more about aeros I keep my eyes open for cars that have interesting aerodynamic features. I find it interesting since most people will find a square trailing edge unappealing simply because they don't have a care for aerodynamic function which sucks frankly.

So far I've seen the square rear edges on newish Subaru impresa hatch...strangely but mad respect to their design teams. Prius no surprises here but still go them. Audi fast back style saloon unexpected as detracts from styling.

I wonder if it is going to be more common to see more and more cars with this feature. I doubt it as like I mentioned from a styling point of view it doesn't really look aerodynamic or beautiful.

Being interested in boat design, I was thinking when we design boats they are either designed primarily for planning or displacement operation. Now how this relates to cars is that all cars operate in a pure displacement environment yet we design them as if we expect them to plane which is really stupid. So most of all our cars are dragging huge wakes behind them which we know is stupid, Strange eh.

[kach22i]

Originally Posted by D15r

Being interested in boat design, I was thinking when we design boats they are either designed primarily for planning or displacement operation. Now how this relates to cars is that all cars operate in a pure displacement environment yet we design them as if we expect them to plane which is really stupid. So most of all our cars are dragging huge wakes behind them which we know is stupid, Strange eh.

Interesting observations, I've seen it and thought along similar lines myself.

I suppose a fully submersible submarine is close to being in a continuous fluid, with air acting like a fluid as well.

The whole ground plane thing (pressure wave) really makes cars/truck unique, aircraft only experience this during take off and landing.

[LittleBlackDuck]

Originally Posted by D15r

So most cars have rounded trailing edges . This we know isn't the best for low drag. As I've learnt more about aeros I keep my eyes open for cars that have interesting aerodynamic features. I find it interesting since most people will find a square trailing edge unappealing simply because they don't have a care for aerodynamic function which sucks frankly.

Nope, some people want a car to just look nice. Beauty is in the eye of the beholder (beerholder? ). Practicality and safety is also taken into configuration by the manufacturer.

I own 3 different hybrid cars - Lexus RX450h, Lexus CT200h and Prius Gen 3. The shapes of each of them was conceived from a different perspective and I can appreciate each of them. The Prius' shape is unconventional but I appreciate it from the space that it adds in the interior as well as the lower drag that it offers.

Not everybody is turned on by an old and tatty looking Honda Insight that has skirts, grille block and a boat tail made from coroplast. I must admit that I would never drive such a conveyance, but I can still appreciate the effort made to reduce its drag and thus its fuel usage.

I also don't expect everybody to like nor agree with what I have chosen to own and drive, but we are all entitled to express ourselves.

Simon

[Erasmo]

Beer holder indeed:

[D15r]

I have to do the walk of shame and clean up what I was saying here.

I thought about this concept of relating car shape to boats displacement planning etc and I got lost somewhere. I forgot my point and so this post was off, basically I had a blonde moment and it has actually taken me sometime to return and fess up.

I see only 300 odd people have viewed so no harm done right.

Anyway to finish up I've been noticing a lot more square trailing edges on cars which I hadn't noticed or known about yet, gtr skyline corvette etc. So there is hope for our species after all, well not really but you all know what I mean.

[Ecky]

I've considered adding sharp edges to the back of my Insight. I'm greatly inspired by OG VX:

[D15r]

[gone-ot]

Yep, you want to 'trick' the airflow into abruptly horizontally-separating from the surface rather than 'clinging' to the the rounded surface as similarly happens at airfoil wingtips not having winglets.

[aerohead]

Originally Posted by D15r

So most cars have rounded trailing edges . This we know isn't the best for low drag. As I've learnt more about aeros I keep my eyes open for cars that have interesting aerodynamic features. I find it interesting since most people will find a square trailing edge unappealing simply because they don't have a care for aerodynamic function which sucks frankly.

So far I've seen the square rear edges on newish Subaru impresa hatch...strangely but mad respect to their design teams. Prius no surprises here but still go them. Audi fast back style saloon unexpected as detracts from styling.

I wonder if it is going to be more common to see more and more cars with this feature. I doubt it as like I mentioned from a styling point of view it doesn't really look aerodynamic or beautiful.

Being interested in boat design, I was thinking when we design boats they are either designed primarily for planning or displacement operation. Now how this relates to cars is that all cars operate in a pure displacement environment yet we design them as if we expect them to plane which is really stupid. So most of all our cars are dragging huge wakes behind them which we know is stupid, Strange eh.

Kamm and Fachsenfeld advocated that the body follow the ideal streamline path and then wherever you want to terminate the length,just chop it as with a loaf of bread.
A current example is Mercedes' 2016 M-B IAA (with some stylistic license)