The Leading Edge by Goro Tamai

[NeilBlanchard]

Kevin Smith of Illuminati Motor Works mentioned this book 'The Leading Edge' by Goro Tamai, and he recommended it highly. Has anyone here on EM read it, and if so what do you think?

[aerohead]

I've avoided it.Tamai made a comment regarding aerodynamics in the mid-1990s which demonstrated a complete lack of understanding about verisimilitude and it put me off so much that I'm uninterested in anything he has to say.
From an ad for the book,I understand that he makes a very contextual argument for aerodynamic compromise with regards to University-constructed solar competition vehicles.He doesn't venture beyond solar race cars.

[NeilBlanchard]

I'm sorry to hear this, Phil. I trust your judgment on things aero. I did already order the book, though, so I'll keep your concern in mind. And I'll spend more time with my 4th edition Hucho, too.

[mallrat]

Let us know what you think, NeilBlanchard. We can hope that the one comment and advert that Phil read aren't an accurate indication of the book as a whole.

[aerohead]

Originally Posted by NeilBlanchard

I'm sorry to hear this, Phil. I trust your judgment on things aero. I did already order the book, though, so I'll keep your concern in mind. And I'll spend more time with my 4th edition Hucho, too.

Information is information and as 'rare' as aerodynamic documents go,whatever is in print is all grist for the mill.And of value,anyway you look at it.
You won't regret purchasing the book.
Hucho's made at least one contextual error in his book(s), regarding Walter Lay's research and results.
Considering the vast amount of material he's had to cover though,you've got to cut a person like him some slack.
Tamai may have 'slipped' with his choice of wording.A technical editor or jury would help catch things.Perhaps (and hopefully) he will flesh out the context in which he makes his points.

[NeilBlanchard]

I got my copy of The Leading Edge yesterday (it is a print-on-demand paperback) and it is heavy on details for solar cars and pedal/electric competition vehicles. It has a LOT of formulas and it covers a lot of the basics as well as in depth minutia.

The couple of things that jumped out at me that I had not run into much before is the term "wetted area" which seems to be the plan area of the vehicle, possibly in relation to the frontal area.

The second thing is junction interference, which comes heavily into play with outboard wheels or canopies that jut up sharply from the top of the vehicle.

He also covers laminar flow quite a bit, and ground clearance and the shape of the underside of the vehicle. Bottom line on ground clearance: lowering the vehicle will *increase* the drag, in all likelihood.

Hucho's book is far broader in scope, and probably more useful overall for most types of vehicles. Tamai's book is very much focused on über low drag vehicles and is also quite useful.

[CFECO]

From Wiki
"In sailboating, the wetted area is the area of the hull which is immersed in water.
In aircraft, the wetted area is the area which is in contact with the external airflow. This has a direct relationship on the overall drag of the aircraft."

So for us, it would be the total 3D surface area I guess. One reason external faired wheels are not the best, so I've heard.

[Frank Lee]

Wetted area would be surface area and the concern there would be skin friction, which Aerohead says is a quite small component of drag for land, or should I say street vehicles. Of course for competition vehicles no stone should be left unturned and they will seek to get competitive advantage whereever they can.

I'd be interested in what he had to say about junction interference but I'd imagine it isn't real deep; we can see from the aviation world how they treat the wing/fuselage junction, and also the tail/rudder/fuselage junctions and they are either dealt with with fillets of modest size or nothing at all. An example from the marine world would be the sail and sail planes on a sub and there too the junctions have modest fillets.

[ausias]

where did you get the hucho book? I want to buy it and get shipped to Europe.
did you recommend any edition? sometimes there are differences that make an edition interesting.
i feel happier saving 2.5L/100 km in a 1400 kg car ( adding 23 us mpg in a 3100 pounds car) than trying to build a solar thing. but i found your reviews very useful. thank you

[gone-ot]

What Princeton (college) says about "wetted area" as applied to jet aircraft (page 12):

http://www.princeton.edu/~stengel/MAE331Lecture4.pdf

Something from Southampton England (slides 4-thru-6):

http://www.google.com/url?sa=t&rct=j...6wIIwbYYOjgh6A