Back on the yaw topic, if I may. Many NACA and NASA reports are available at the NASA Technical Reports Server at URL
http://naca.larc.nasa.gov/search.jsp. References useful at typical LSR speeds mostly date from WWII and earlier, before jet engines enabled higher Mach number speeds. Several such reports are listed on my website, and I am sure that there are many more in the database.
A very readable report that is germane to this yaw discussion is Hoggard, H. P., “Wind-tunnel Investigation of Fuselage Stability in Yaw with Various Arrangements of Fins,” NACA TN 785, 1940 (Document ID: 19930081581, Accession Number: 93R10871). Jon is spot on with the assertion that hindering airflow over the top of the vehicle will counteract yaw. This is likewise true of the bottom of the vehicle. This report shows to what extent dorsal fins on the rear portion of the fuselage counteract yaw, which helps to choose fin location and height. Fins on the forward portion of the fuselage destabilize the vehicle.
I plan to use both dorsal and ventral fins on my streamliner, 2 to 3 inches high on most of the hear half of the body. I am toying with the idea of adding side fins, to act as dorsal and ventral fins just in case it ever happen that I am sliding on my side hoping to remain pointed downrange. I am told that it happens.
Disclaimer: Always keep in mind that wind tunnel data taken from a model suspended in a test section is not necessarily directly valid for a wheeled ground vehicle.
Another interesting NASA article is
Benson, Tom, “Determining Center of Pressure,” NASA model rocketry website
http://exploration.grc.nasa.gov/education/rocket/rktcp.html.
I recently noticed that my polycarbonate eyeglass lenses have pits in them, even though I wear a face shield and ear muffs when grinding, and a helmet always when welding or riding a motorcycle. I wear ear muffs for just about everything except listening to music and my wife, trying to save what little hearing is left after open pipes, guns, wailing amplifiers, and having an artillery simulator go off just as I came up out of a gully, back when I was young and foolish (I am no longer young).
