Book on history of car aerodynamics

[freebeard]

Thanks. It's hard to tell but I don't see mention of the rounded nose of the Type II Transporter.

...I just am not much interested in racing cars

And yet the Bluebird gets six pages?

[JulianEdgar]

Originally Posted by freebeard

Thanks. It's hard to tell but I don't see mention of the rounded nose of the Type II Transporter.


And yet the Bluebird gets six pages?

The Transporter is covered twice, once specifically for its rounded nose and a second time in an extract from Hucho's autobiography dealing with front-end radii.

I don't categorise Land Speed Record cars as 'racing cars'.

[aerohead]

Originally Posted by JulianEdgar

I thought of it but couldn't find any detailed info on the car's aerodynamics.

A Member shared an online article about the A2 a few years back.
One of the European universities took an A2 into a wind tunnel and did a progression of mods.
Starting with Cd 0.288, they got it down to Cd 0.204, illustrating the drag evolution, item by item, as the modifications piled on.
If someone doesn't beat me to the citation, I'll try and grab it for next time.
I think you'll like it.

[Vman455]

The article (not the Powerpoint slideshow, which has been posted here before but doesn't contain all the data) was published in Sustainable Vehicle Technologies: Driving the Green Agenda (Cambridge: Woodhead Publishing Limited, 2012). JP Howell conducted the research for Tata in partnership with the Low Carbon Vehicle Technology Project and wrote the article, pp. 145-154. But, this article isn't about the development of the A2; rather, it's an investigation of drag reduction of an A2 and a Tata Vista that was intended to inform Tata's further development of EVs. The most interesting part is the comparison of the A2 tested with the same modifications in the fixed-floor MIRA tunnel and the moving-ground S2A tunnel.

[JulianEdgar]

Originally Posted by aerohead

A Member shared an online article about the A2 a few years back.
One of the European universities took an A2 into a wind tunnel and did a progression of mods.
Starting with Cd 0.288, they got it down to Cd 0.204, illustrating the drag evolution, item by item, as the modifications piled on.
If someone doesn't beat me to the citation, I'll try and grab it for next time.
I think you'll like it.

Thanks, but not really relevant to the book I am working on. (The book is not about modifications.)

[aerohead]

Originally Posted by JulianEdgar

Thanks, but not really relevant to the book I am working on. (The book is not about modifications.)

Just thought the reader might find it interesting that, in 1999, a vehicle like the A2 had the makings for Cd 0.204, which is just now available with the Tesla Model S Plaid / Hyundai Sonata Hybrid ( if fully electrified ).

[JulianEdgar]

Originally Posted by aerohead

Just thought the reader might find it interesting that, in 1999, a vehicle like the A2 had the makings for Cd 0.204, which is just now available with the Tesla Model S Plaid / Hyundai Sonata Hybrid ( if fully electrified ).

Maybe. But I think that they will find the 1939 Schlör car's 0.189 Cd even more interesting!

No, I am not covering any modified cars in this book - that belongs in my Modifying the Aerodynamics of Your Road Car.

Having said that, the author of the cited chapter (Jeff Howell) is one of the reviewers of this current book, and he is being outstandingly helpful.

I am trying to wrap-up the aero history book up fairly soon, as my 'proper job' (training people in writing skills) is finally picking up post-Covid.

[JulianEdgar]

The book is progressing. Professor Jeff Howell, particularly, has been brilliant in critiquing my mistakes and also providing new information.

The 1960s Donald Campbell Land Speed Record Car (Bluebird) section is currently undergoing its third re-write, as Professor Howell (a) corrects my mistakes, and (b) provides new information. Incredibly, he has given me a copy of the original wind tunnel tests of the Bluebird models, conducted at the Imperial College (London, UK) wind tunnel. The graphs in the report are drawn in pencil on graph paper! I think that my book will be the first with detailed aero info on this car. I was lucky enough to see Bluebird in the UK a few years ago and it remains my favourite LSR car.

Dr Thomas Wolf of Porsche has also become intrigued by the Type 64 Porsche (the pre WWII car designed for the 1939 Berlin–Rome long-distance race that was cancelled because of WWII). He has been investigating historic resources inside Porsche and doing lots of calculations of the car's likely drag coefficient.

MIRA (the UK's Motor Industry Research Association) is providing me with info on their 1960 full size wind tunnel - Jeff Howell said that if I was going to cover the FKFS and VW tunnels, I had to cover the MIRA one!

In the US, GM has given me permission to use a lot of tech info on their 2019 Chevrolet Corvette C7 ZR1 (but unfortunately, no coefficients of drag or lift), and Rob Palin (ex Tesla) has added a lot of great personal commentary to my coverage of the development of the Tesla Model S.

Porsche has also given me permission to use detailed info on the Taycan, and has provided high-res pics.

There are a few other cars I am hoping to get detailed aero info on (but as soon as I say that I preferably want Cd, CLf and CLr figures, a lot of manufacturers go quiet) but some signs look encouraging.

And from EM, Vman455 has been proof-reading (he's very good - I think he could get a job as a proof-reader/editor), and I have used the Ford Sierra patent that Aerohead linked to explain how the bi-plane Fiord rear wing works.

[aerohead]

Julian, have you seen the hand-built recreation of the car?
It's been wind tunnel tested in the USA. So far, the owner hasn't revealed the data, however, that could change. That would be a great public service.
Roughly gauging the Porsche with the V2 Sagitta numbers, the mirror-delete and turn indicator delete alone would put the 60K10 around Cd 0.207.
The Porsche's front skirts are more full-coverage.
Windshields are different.
A variability with wipers between iterations of the car.
No idea if the tire width is different.
'hope I live long enough to find out.

[JulianEdgar]

Originally Posted by aerohead

Julian, have you seen the hand-built recreation of the car?
It's been wind tunnel tested in the USA. So far, the owner hasn't revealed the data, however, that could change. That would be a great public service.
Roughly gauging the Porsche with the V2 Sagitta numbers, the mirror-delete and turn indicator delete alone would put the 60K10 around Cd 0.207.
The Porsche's front skirts are more full-coverage.
Windshields are different.
A variability with wipers between iterations of the car.
No idea if the tire width is different.
'hope I live long enough to find out.

Yes I saw a pic of the replica in a tiny wind tunnel. I'd be reluctant to quote any figures from that. I did ask Dr Wolf if he could get the remaining 'real' car into the Porsche wind tunnel, but he didn't reply to that - other than to say the car is not owned by Porsche.