Basics of a landspeed racing machine
(OK, primarily with reference to special construction classes)
1. Not an aircraft; i.e. dependent on the Earth for support against gravitational forces
2. Propulsion via rule limitations of the sanctioning body for the speed trials and record recording
3. Safe enough to satisfy all the stakeholders in its operation
4. Primary design purposes: Minimize aerodynamic drag, maximize available power in the same physical package and operate for long enough to achieve its objective. (usually but not always to set a record)
5. The machine must be something capable of being built with an attendant expenditure of resources and some risk of failure. Unbuilt and untested conceptual designs at any stage of development really don't count for a lot.
6. Some practical observations born of recent experience with organized land speed trials (not really races in the sense that a race is two or more cars on the same track competing against each other to determine who finishes a course first).:
a. Otto and diesel cycle internal combustion engines are the most common power source. Electric motors are gaining interest. Hybrids are just an interesting mix of energy source/storage/conversion schemes. Ditto fuel cells.
b. Streamlining (reduction of drag coefficient) gets much attention; less so the important other half of the equation, frontal area.
c. Maximum power output per cubic inch of engine displacement is sought. Sanctioning body rules often handicap easily measurable engine variables such as displacement, fuel type and induction methods and occasionally basic design features such as with Wankel rotary engines.
d. Trials courses are long and straight to reduce any handling and acceleration advantages of the vehicle to at most second order influences on measured speed.
e. There tend to be fairly elaborate safety requirements generally unique to individual racing venues but still with much in common. Born of decades of experience and mostly concerned with protecting human life and limb they sometimes have a restricting effect on vehicle performance.
f. Organizations that sanction and conduct meets tend to be small and limited in resources. Their rule books lean heavily toward safety rules but in general do not try to cover every possible situation whether the question be one of safety, vehicle classification or event management. As a result the final word on disputes rests with the duly appointed managers of the enterprise. Rulebooks are always a guide. They are not legal codes subject to challenge in a court or formal appeal process like the legal systems under which governments function. Best to reflect on that while building or fuming over a tech inspector's request that something be changed before you can run your car.
g. A lot of crazy ideas have been tried and didn't work over the last 75 or so years. This history is worth paying attention to.
h. We still need human drivers in LSR. In spite of the success of R/C technologies in model cars as well as unmanned aircraft we still have a ways to go before we automate even some of the traditional driver's tasks let alone all of them. The biggest question is and will be for a long time how to insure that an unmanned LSR vehicle won't be a hazard due to uncontrolled departures from its planned course.
i. I can see the day when a fully recumbent driver won't need an optical periscope (tried in LSR from time to time) because the electronic front and side looking display is built right into his helmet and the controls are entirely "fly by wire". Likely not while I'm still around.
OK time to design an LSR machine.
I submit that frontal area is the biggest deal. The frontal area of a reclined driver surrounded by roll cage and required helmet and padding is the start. (take note of Jack Costella's success, in spite of his resource limitations, through focusing on that one issue) Next add to that frontal area of the wheels that extend below the body. That will be determined by the combination of course roughness and requisite suspension travel (remember the frame structure flexes a bit too). We pretty much know how to get the right body, nose and tail shape as well as other tricks of the aircraft designer. Notice there is scant mention of the vehicle length here. Practical considerations like getting it on and off the trailer are a possible limit. So is the length of your workshop (which seemed to be only a nuisance impediment to Al Teague)
Obviously the engine/driveline package frontal area should fit inside the basic driver profile. Doesn't matter how long it is. Sure there are limitations. To the extent that your ingenuity overcomes them you are better positioned than the next guy to set a new streamliner or lakester record.
Hint: Take a look at high speed bullet trains. How can they go so fast? They just add more cars each with their own electric motors behind the fixed frontal area of the leading "locomotive". Why don't they just make one locomotive real long? Because they have to be able to go around long sweeping curve tracks. Also the structure would sag in the middle. Also note that the European and Japanese bullet train rails are on concrete tie foundations. Here in the US we use wood ties on rock ballast on most class 1 railroads. Fine for crossing hundreds of miles of prairies and mountains. Not so fine for 300mph trains.
Chew on this…………Yeah, I know, as one with a BMI of 30 and a love of recumbent activities, preferably while steering a brew in the proper direction, it's easy for me to suggest cockpit configurations fit only for a subteen female gymnast. A bit more difficult to cope with them ……….Ed Weldon
When the Stanley car set a land speed record of 127 mph at Daytona, nothing remotely like it had ever existed.
http://www.steamcar.net/stanley/fastest.pdfAlthough it took Reid Railton two design iterations (1933 and 1935) to get Sir Malcolm Campbell's Bluebird to go 300 mph, Railton went directly from the first 300 mph car to the first 400 mph car by, among other things, dumping all the design concepts he'd previously used.
Athol Campbell had never built a racecar in his life. The closest thing to Graham's City of Salt Lake was Campbell's Bluebird (single water cooled V-12 aircraft engine with rear wheel drive), except Graham's car weighed 4,000 lbs instead of 10,000 lbs and went over 40 mph faster. Had Mickey Thompson not beaten him to it, Graham would have been the first American driver to go 300 mph. For many years afterward, Graham's was the fastest single engine rear wheel drive car in history.
The first jet land speed car wasn't designed by observing other jet land speed cars.
When Breedlove, the Arfons brothers, and Gabelich were going for the record, USAC steward Joe Petrali had to tech inspect for safety cars for which there were no established rules and which had never before existed.
If anyone ever gets serious about building a wheel driven car with the least frontal area and most horsepower is when we'll finally see a land speed car powered by a nonairbreathing gas turbine.
