- 1993 "Maize & Blue" University of Michigan Solar Car
The 1993 Maize & Blue solar car was built by the
University of Michigan Solar Car Teamduring the period from 1990to 1993.
The car was raced in two races. The car won a national championship in Sunrayce 93, the predecessor race to the
North American Solar Challenge. It then went on to finish 11th in the 1993 World Solar Challenge. Maize & Blue is now part of the permanent display at the Museum of Science and Industry in Chicago, Illinois. The car had an evolutionary design descended from the General Motors Sunraycerand the University of Michigan's first generation car, Sunrunner. The car is considered an early example of and demonstration platform for energy efficient automobiledesign.
. The team that raced in 1993 was the second generation “Maize & Blue” team (team tradition dictates that each team names their car and that team is known by the name of their car). The Maize & Blue team was formally established in October 1990 and completed in December 1993.Over a three year period the team designed the car, built a prototype chassis, tested the prototype, built the race vehicle and then tested that vehicle in preparation for the two races.
The team was founded by a few individuals and grew to its peak of several hundred students from all academic disciplines. During design and construction, the team was at its largest in numbers. During testing and the actual races, the team shrunk to a core group dubbed the “race crew” composed of approximately 30 students and advisers., who participated in the early phase of the project but did not play a significant role in the final phases. In total approximately 70,000 hours of student labor were invested in the project.
Maize & Blue combined technology typically used in the
aerospace, bicycle, alternative energyand automotiveindustries. Unlike typical race cars, Maize & Blue was designed with severe energy constraints imposed by the race regulations. These rules limited the energy to only that collected from solar radiation and as a result optimizing the design to account for aerodynamic drag, vehicle weight, rolling resistance and electrical efficiency were paramount. Conventional thinking had to be challenged, for example, rather than a conventional automobile seat which would weigh tens of pounds, Maize & Blue employed a nylon mesh seat combined with a five-point harness that weighed less than 3 pounds.
One of the cutting edge, at the time, processes that the team employed in designing Maize & Blue was computer aided design. CAD was used to design almost all of the car using Dassault Systems'
CATIAand then modeling the physical characteristics using SDRC I-DEASand other programs most running on some IBMRS/6000 Unix workstations donated by team sponsor IBM.Initially several hand built foam quarter scale models were constructed and tested in the University of Michigan's subsonic low turbulence 5' x 7' wind tunnel. This testing was instrumental in determining the ultimate vehicle configuration. Once finalized, the body of the car was NC milled in quarter scale from the CATIAmodel and verified in wind tunnel testing. On May 8, 1993, Maize & Blue was tested in a full scale wind tunnel at Lockheed's facility in Atlanta, GA.
Obtaining cash and in-kind donations was critical to the completion of Maize & Blue. Early on in the project, the team created a dedicated group focused on raising funds. Team sponsors ranged from the University of Michigan itself to corporate sponsors and university alumni. In total, there were hundreds of sponsors who contributed to the project. Corporate sponsors included
Ford Motor Company, IBM, Northwest Airlines, General Motors, 3M, [http://www.magnetek.com/ Magnetek] , TRW, [http://www.monroe.com Monroe] , BASF, Dana Corporationand many others. Among the individual alumni sponsors, University of Michigan alumni [http://me.engin.umich.edu/news/pubs/mechanica/spring2000/eab.html Charles Hutchins] stood out as a major contributor.
Component, system and vehicle testing was a continual process throughout the process and began very early on in early 1991. An initial vehicle design for Maize & Blue had a three-wheel configuration with one wheel in front which afforded significantly improved aerodynamics but introduced handling concerns. In 1991, the team built a “test buck” which was used to evaluate the handling characteristics of the tricycle configuration. As a result of these tests, the design was abandoned in favor of a more conventional, and more stable, four-wheel configuration.In early 1992, the team constructed a prototype chassis based on the final vehicle design for Maize & Blue. This prototype chassis was tested in excess of 1,000 miles on closed courses, primarily the
Michigan International Speedwayin Brooklyn, Michigan.A final round of vehicle testing was conducted in San Angelo, Texas, at the Goodyear Proving Grounds and on nearby roads. Also, the team completed three days of testing on the actual race route the week prior to the start of the race (primarily to get a feel for the actual route and traffic patterns).
and qualified to start in the 10th position.
The race was held over seven days from June 20-26, 1993. The race began at the recently-opened Ballpark in Arlington (now known as Ameriquest Field) in
Arlington, Texasand finished at the Minnesota Zooin Minneapolis, Minnesota.
By the end of the first race day, Maize & Blue had moved from 10th into 1st place, just a few minutes ahead of the second place car from [http://www.csupomona.edu/~capset/web_pgs/intrepid.html Cal Poly Pomona] . Pre-race favorite [http://www.calstatela.edu/academic/engr/solar_e/solar_e2.htm Cal State LA] suffered debilitating electrical failures on day 1 putting them out of contention for the remainder of the race. Over the next three days, the team jockeyed for position at one point falling behind first place by as much as 20 minutes, primarily due to two penalties levied by race officials for violation of traffic rulesPopular Mechanics, September 1993] .
On day 5 of the race, the weather forecast called for rain and overcast conditions for most of the day. Maize & Blue was the only car to finish that leg of the race under its own power (the Iowa State University car finished ahead of Michigan, but incurred a 10-hour penalty for replacing their battery pack at the start of the day
PBSScientific Frontiers hosted by Alan Alda, November 3, 1993, (20:00)] ). On day 5, the Michigan team accumulated a 90-minute lead over the next fastest car.
Days 6 and 7 were uneventful with Maize & Blue maintaining its lead and finishing in [http://www.formulasun.org/history/sunrayce_93.html first place] overall followed by Cal Poly Pomona in second and Cal State LA in third. Maize & Blue finished with an average speed of 27.29 mph over the 1100-mile course edging out the second place car by 90 minutesPopular Mechanics September 1993"] . The victory gave Michigan its second consecutive national championship in solar car racing.
1993 World Solar Challenge
Between Sunrayce 93 and the 1993 World Solar Challenge, the team made many changes to Maize & Blue, the two most important being replacing the lead acid battery pack with an equivalent capacity silver-zinc pack with resulted in a significant weight savings and the other being replacing about 40% of the solar cells with high-powered "Green Cells" produced specially for the team by Dr. Martin Green at the University of New South Wales. Unfortunately, as a result of an assembly flaw during the encapsulation process the new cells were unable to produce peak power output resulting in "lower" total array power.
As a result, Maize & Blue finished in 11th place in the 1993
World Solar Challenge. Hondawon the 1993 World Solar Challenge followed by the team from Biel University. Maize & Blue finished the race ahead of the 1990 University of Michigan Sunrunner's record of 5 days, but that was not enough for a top finish.
*Drag Coefficient, Cd: 0.115
*Frontal Area, A: 1.16 m^2 (12.53 ft^2)
*Drag Area, CdA: 0.133 m^2 (1.44 ft^2)
*Measured full scale in the Lockheed, Atlanta, Georgia, 4.9 x 6.1 meter (16 x 20 foot) wind tunnel with boundary layer blowing to simulate moving ground plane ;"Chassis:"
* 6061-T6 Aluminum tubing space frame, 2.54 cm (1 in) OD, 0.11 cm (0.045 in) wall
Nomexbody, Kapton insulators between panel and body
* Weight w/o Driver: 358 kg (790 lb)
* Length: 5.75 m (18.87 ft)
* Width: 2 m (6.56 ft)
* Height: 1.1 m (3.61 ft)
* Wheelbase: 2.2 m (7.22 ft)
* Track Width: 1.89 m (6.20 ft)
* Clearance: 0.45 m (1.48 ft)
;"Wheels and Tires:"
* 36 spoke, 43.18 cm (17 in.) wheels with spoke covers;
* Michelin 43.18 x 3.18 cm (17 x 1.25 in.) slick tires @ 150 psi
* Number of wheels: 4
* Est. Tire Rolling Resistance Coefficient: 0.0060
;"Brakes, Suspension, and Steering:"
* Hydralic motorcycle disk front brakes
* No emergency brake (used chocks)
* Custom titanium suspension parts. Modified MacPherson strut with Monroe custom shocks in front, 86 lbf/in (15.1 N/mm). Separate coil spring. Trailing arm rear, with 236 lbf/in (41.3 N/mm) coil over shocks
* Rack and pinion steering with two redundant push-pull cables
* Direct drive chain to rear wheel
* 2.06/1 ratio typical
* Motor: Custom [http://www.magnetek.com/ Magnetek] DC brushless, 1.8 kW rated, 3.7 kW max, 2250 RPM, 100 volts, 14.5 kg (32 lb), 93% efficient at operating power level, 95% peak efficiency. Blower cooling
* Controls and Instrumentation: Constant power / constant speed motor controller. Telemetry of voltages, currents, temperatures, and speed to chase van
* Batteries: Eagle Picher, 3 parallel packs, 96 volts, 4.8 kW·h, 54 A·h, 154 kg (340 lb)
* Type of Solar Panel: Fixed panel with eight gently curved facets
* 8 facets of 3 modules each
* [http://www.bp.com/modularhome.do?categoryId=4260&contentId=7004852 BP Solar] Saturn Cells, Laser grooved, Monocrystaline Silicon, 7615 cells, 90% area packing, 17% single cell rated efficiency, 16.3% mean single cell observed efficiency measured at
TRWin Redondo Beach, CA. Average was for 8000 cells processed. Overall panel efficiency 14.5%, 1300 watts peak. Note that for the World Solar Challengeapproximately 40% of the array of BP cells was replaced with higher efficiency silicon cells manufactured by Dr. Martin Green at the University of New South Wales
* 8 [http://www.windsun.com/ChargeControls/maximize.htm AERL] peak power trackers
* Panel voltage: 130 volts
Maize & Blue and the team received prominent press coverage and recognition including:
* The [http://www.umich.edu/~urecord/9293/Jul19_93/14.htm University Record] July 19, 1993 by the Regents of the University of Michigan
* [http://www.abc.net.au/quantum/solarcar/1993wsc.htm Australian Broadcasting Corporation] November 7, 1993
Popular MechanicsSeptember 1993, page 104
CNNEarly Prime, June 20, 1993, 3:25PM, (0:30)
CNNHeadline News, June 27, 1993, 5:57PM, (0:25)
CBSThis Morning, June 23, 1993, 8:33AM, (4:00)
NBCSaturday Today, June 5, 1993, 7:50AM, (1:30)
FOXKSHB-41, Kansas City, June 23, 1993, 10AM Live, (15:30)
PBSScientific Frontiers hosted by Alan Alda, November 3, 1993, (20:00)
* [http://www.umich.edu/news/MT/ Michigan Today] , October 1993, Volume 25, Number 3, Cover Story
Ann ArborNews Sunday Edition, April 11, 1993, page C1
Ann ArborNews April 10, 1993, Cover Story
* [http://www.michigandaily.com Michigan Daily] , October 2, 1993, page 5
, where it now resides as part of its [http://www.msichicago.org/exhibit/transport/index.html Transportation Zone] exhibit.
Beginning in early 1994, the Maize & Blue team began the transfer and hand over to the third-generation team and thus concluded the project.
List of solar car teams
World Solar Challenge
North American Solar Challenge
* [http://www.umsolar.com/ UM Solar Car Team]
* [http://www.americansolarchallenge.org/ North American Solar Challenge]
* [http://www.wsc.org.au/ World Solar Challenge]
* [http://www.opencortex.org/ Open Cortex]
List of team members
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