On cars, old, new and future; science & technology; vintage airplanes, computer flight simulation of them; Sherlockiana; our English language; travel; and other stuff
VIRTUALLY, THE Land Speed Record car of Leopold F. Schmid has achieved its design goal of 800 km/h, 497 mph or 432 knots. I include this third equivalent unit because my GMax-built Schmid LSR performed this feat on the Bonneville Salt Flats in Microsoft Flight Simulator.
Porsche engineer Schmid designed his LSR car in the mid-1950s, though the concept never came to life. For the tale of his endeavor, see http://wp.me/p2ETap-2bC. For details of the craft’s GMax fabrication, see http://wp.me/p2ETap-2bV.
A 50 Percentile man finds the cockpit of the Schmid LSR a tight fit. The Henry Dreyfus Associates’ book The Measure of Man and Woman was useful in GMax modeling of the driver. See http://wp.me/p2ETap-2cl.
The LSR had a Bristol Siddeley Orpheus jet engine. And to skirt regulations requiring propulsion by wheel, Schmid placed a geared paddle wheel in its exhaust stream. He claimed it produced 40 percent of the LSR’s propulsion.
Now he would know, wouldn’t he?
Importing any model into the flight sim is a multi-step process. Necessary dimensional details such as frontal area and the like are defined in a graphical Model file. A separate Configuration file defines center of gravity, contact points, power and other dynamic data. The two files are independent to the point that it’s possible to make a brick fly like a Cessna 172. Or vice versa.
Though FS2004 is an aircraft sim, it can be finessed to accept a car with reasonable verisimilitude. (I modeled a functioning Cooper Formula 3 car as cargo for my Miles M.57 Aero Van; see http://wp.me/p2ETap-255.)
Schmid’s book provided most of the necessary Configuration details, though I had to guess on things like Moments of Inertia for roll, pitch and yaw. I found the model displayed the best stability when its Airplane Geometry portion was ignored. One day I must fool with negative lift to see if downforce can be modeled.
In my initial setup, I misunderstood Schmid’s citation of 2200 kp of static thrust. “Kilopascals?,” uh, no; but I seriously overpowered the Orpheus jet engine. My LSR exceeded even Schmid’s prediction of a theoretical top speed of 1140 km/h (708 mph).
In its first Bonneville test, my LSR reached 1000 km/h lickety-split, albeit launching itself into the air on the slightest provocation of Bonneville terrain.
Come to think of it, Schmid did write, “Part III shows how the body must be shaped after the latest knowledge in order not to be endangered by sidewinds.”
It turns out, though, that 1 kp is 9.80665 N. The Newton; there’s a unit we can get our hands on. Or better yet, 1 kp = 2.2046 lbforce, this last word uttered sotto voce but included just in case any physicists are listening.
Hence, the LSR’s Orpheus actually produced a static thrust of 4850 lbforce. And we’re ready for a proper Bonneville run.
Microsoft Flight Simulator records its activities as .fsr files, a format useful only in the sim. But www.fraps.com offers Real Time Video Capture & Benchmarking; and Windows Movie Maker transforms this into the proof of Schmid’s concept shown here.
All in good fun, and onto my next GMax project. Hint: Its topic is almost 140 years old. ds
© Dennis Simanaitis, SimanaitisSays.com, 2014