SHOULD THE VEHICLE DIMENSION REQUIREMENTS BE CHANGED?
In ASC2003, vehicles could have Classic, ISF5000, or 2-Person (Classic) dimensions. The 2003 Regs stated that Classic dimensions will probably not be allowed in ASC2005.
What are your thoughts? How to submit your response.
RESPONSES (Generally listed with newest response first.)
RESPONSE#7
[text related to other questions removed]
I don't think requiring a two passenger car is the way to go at all [refers to Response#6]. It
would require essentially every car to be rebuilt from scratch, which a
number of teams will be unable to do. There are only 3 cars in the
world that I know of that fit this configuration: the University of
South Australia's Ned and Kelly, and Queen's University's Genesis. All
others would start over, which many do anyway, but which many also do
not. Besides which, solar arrays for a two person car with the regs as
they currently stand allow for 50% more array power than a single seater
car. The tradeoff of adding weight for array power could actually be
beneficial, though it depends greatly on the the course. I don't think
this is a formula for slowing down the cars. You are corrent that the
PR value of such a configuration is high, but I think that PR value and
the construction of such a car is more a result of a particular team's
goals than it is about the car's performance. Leave the design options
open as much as possible.
FROM: Jason Kramb,
University of Michigan Solar Car Team Alumni,
Driver / Chief Aerodynamics and Body Engineer '99,'01
RESPONSE#6
[text related to other questions removed]
Going to a two-passenger, side-by-side forward facing seating
configuration would add weight and impact array coverage, which might
slow cars down. This might also make the cars appear more practical in
the eyes of the spectators. (And it would be kind of like the old days
of racing, where both a driver and a mechanic rode in each race car.)
Regards,
FROM: Carl,
Sunrayce 95 Participant
RESPONSE#5
With the current regulations, the solar cars are about the same size as a
Chevy Impala (just a little wider). This is a good size for a vehicle,
including solar cars. Race officials should not use the size of the array
or vehicle to try and adjust the performance of solar cars. If the size
approach is taken, how small do we go? If cars still go too fast in the
next race, do you make them even smaller for the following race? This is a
path we shouldn't head down.
Bringing down speeds of fast solar cars should be achieved by extending the
racing time each day.
Average Driving Power = Solar Energy/Driving Time.
By extending the racing time, the driving time denominator is not only
increased but the total solar energy is decreased because more time is spent
driving in low angle light, instead of pointing directly at the sun to
charge. If the racing started at 7:30am instead of 8:00am and ended at
6:30pm instead of 6:00, cars would have 11%-12% less power to use going down
the road. ASC should tweak the driving time so that teams are rarely
limited by the speed limit. This method allows for continuous adjustment as
cars get even faster in the future while maintaining continuity of vehicle
regulations. This method also has the added effect of cars going further
each day, so races could be 7 days instead of 10 for the same distance (an
idea some ASC planners might like).
FROM: Nathan Rues,
42
RESPONSE#4
The change in sizing reg moved the optimization problem from most teams
trying to fit a fixed sized (8m^2) array on the smallest car (for aero and
weight), to teams trying to fit the largest array on an essentially fixed
size car. Some limit needs to be put on the size of the car, just as
there is for basically every other form of racing, or we would, for some
reason or other, see a 10ft wide car that would fit on interstate lanes,
but not the small town main street that we also drive through.
Historically, this limit was arbitrarily set (though I'm sure there is
some reason for these numbers) for solar cars at 6m x 2m x 1.6m. I guess
my question would be why try to make the cars larger? Like I said, the
regs currently allow for a 9m^2 array with some sort of flat panel
rectangualr array. You sacrifice some amount of array area to improve
your aerodynamics by rounding the leading edge and sides, and by adding a
canopy somewhere in the middle. I think that is a much more interesting
optimization problem. While it does limit some variety in vehicle sizes,
I don't think your original argument that it takes away from the
variations possible for cars that do not have thier array integrated with
the cars leading edge. I've seen cars where most of the entire body is
one piece, cars where the upper surface splits the car exactly at the
stagnation point on the leading edge, and cars that integrate thier
leading edge with the lower surface of the car and don't start their array
until further back on the upper surface. Again, I think it comes down to
a optimization problem, but one that also includes manufacturing
techniques and the skill sets of the those doing the construction.
FROM: Jason Kramb,
University of Michigan Solar Car Team Alumni ,
Driver / Chief Aerodynamics and Body Design Engineer '99, '01
RESPONSE#3
I see this as a rule where there is no need for a rule.
Why should there be a limit on the geometric car size,
other than being able to fit in a lane?
One always has the option of building a short car.
FROM: Jerry Knight-Rubino, University of Arizona 2003 Team
RESPONSE#2
This [refers to Response#1] was essentially how the regs were specified pre-2001. The cars were
a max of 6x2x1.6 with the array limited to 5x2x1.6 (or 4.44x2x1.6 for WSC)
with a max of 8m^2. The current ISF regs were designed for two reasons,
first to make it easier for the cars to be measured. It is much easier to
simply measure the extents of the car to make sure both the car and array
are within the regs, than it is to measure both car and array separately.
Also, the smaller width car was created to make shipping the cars to
multiple international evert easier in a standard shipping container. The
current regs allow for a max of 9m^2 of array (with a flat rectangular
array). How much you reduce that size through aerodynamics, canopy, etc
is part of the optimization process and design of the car. The best cars
still fit at least 8m^2 of array on thier car, so I don't see much a
a reason to move backward again.
FROM: Jason Kramb,
University of Michigan Solar Car Team Alumni ,
Driver / Chief Aerodynamics and Body Design Engineer '99, '01
RESPONSE#1
Allow the car to be bigger than the array
Why: The current rules allow a max array and car size of
5m x 1.8m x 1.6m. This means that there is a severe
penalty for cars with a nose that is not integrated
into the leading edge of the array. This really
limits the variations possible for solar cars, and
forces the rayce cars to diverge from the design of
practical vehicles. While this is a race and not
necessarily about designing practical cars, the
rules should not force us away from practicality.
FROM: Jerry Knight-Rubino, University of Arizona 2003 Team
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