AppendixResearch Car from the AcademeFrom October, 1979 to September, 1981, about 35 student engineers and instructors at four technical universities in West Germany worked full time to create a research car. They were sponsored in part by a grant from the BMFT. The project was coordinated by Professor Bert Breuer in Darmstadt.The result is a roomy family car with sedan/wagon profile, diesel power, and front-wheel drive. The project came into being under the same BMFT program in which Audi, Mercedes-Benz, and V olkswagen participated. But in September, 1981 it was announced that only the Uni-Car (University-Car) qualified for continued BMFT funds. Support for the other projects was terminated. This left the car companies to pursue their research an development work independently.Whether the Uni-Car is better than what the motor industry can com up with or not, it is worth a closer look. A lot of thought has gone into it, and some of the solutions are daring yet realistic. The universities placed greater emphasis on passive safety than the car companies. Throughout the car, its designers have aimed for new solutions in simplified maintenance, easier repairs, and longer life. Suitability for mass production also has been a fundamental requirement.Foremost among the design objectives was a 25-mpg average fueleconomy for a four seater with 900 pounds payload capacity and a range of 250 miles. Moreover, it should have a top speed of at least 90 mph and be able to accelerate from 0 to 60 mph in no more than 13 seconds. Other goals concerned noise, exhaust emissions, durability, recyclability, and energy use during manufacture. It is not a production prototype, but a carrier of ideas that can help put new solutions into the service of the industry.The Uni-Car was designed for a 108.3 inch wheelbase with a track of 57 inches in front and 54.3 inches in the rear. Its overall dimensions are 181.1 inches in length, 69 inches in width, and 54 inches in height—running on 175 HR-15 tires.The weight target was 2756 pounds maximum (anything lighter would have been preferable).But during the construction period, it was found that the target could not be met, and the prototype ended up with a dry weight of 3032 pounds.The team from the Stuttgart Technical University, led by Professor Ulf Essers, was assigned the body design, aerodynamics, ventilation, and noise control. The wind tunnel work and consequent modifications were carried out by Jurgen Potthoff.Professor Hermann Appel and Professor Hans-Peter Willumeit of the Technical University of Berlin led the team that concentrated on body structure, ergometrics, occupant protection, interior layout, andnonaggressivity to pedestrians. Thus there was close cooperation between the two teams from beginning to end. Karosseriewerk Karmann was brought in as a subcontractor for the actual building of the body. The main structure is made of steel. The roof is a sheet-steel panel, but the doors and tailgate are made of aluminum to save weight. The hood is mainly plastic, and attached to an aluminum frame.Once the basic interior space requirements had been formulated, body design was directed by aerodynamic principles. Four different shapes were tested on 1/5 scale models in the wind tunnel, and the Kamm-back winner was chosen for further development. The final model proved to have a Cx as low as 0.226. That led the team to the conclusion that a drag coefficient not exceeding same design. In fact, the basic shape was so favorable, and Potthoff’s fine-tuning so successful, that the actual car has drag coefficient as low as 0.24. “And further improvement is still possible,” says Potthoff.Among its notable design features is the smoothly rounded nose where bumper, lamps, and plastic hood blend into an unbroken surface. The body has a pronounced taper from the A-post to the rear end panel. The small, silenced air intake integrated with the bumper, air extractors in the forward edge of the front doors, faired-in outside mirrors, flush-fitting wheel covers and full-panel rear fenders, play small but vital roles. Various refinements were added for their potential role in adding toactive safety. For instance, the big housings for the outside mirrors also contain wiper mechanisms for the wiper arms that sweep the front door windows. The mirrors are not unusually big. The size of housings is due to the requirement for allowing the mirrors to yield in impacts with pedestrians. At the same time, the springs and hinges must be sufficiently strong to prevent accidental damage, and the linkage could not be miniaturized.The steering wheel is taken from a BMW. And VDO supplied the instrumentation using liquidcrystal displays.In addition to the energy-absorbing front end and the side-impact protection built into the doors, the Berlin team made some interesting decisions. They decided to fix the front seat in place and back it up with a steel bulk-head running the full width of the car (form B-post to B-post). That will guarantee adequate survival apace even in a frontal collision at any speed where seat belts will save the occupants.Fixing the seat made it necessary to provide a wide range of adjustment for the pedals as well as the steering wheel. The seat belts do not have their locks in the middle of the car —as is common practice because the B-post makes the most convenient anchorage point for the upper-torso end of the belt —but next to the doors so as to facilitate unlocking by outside persons coming to the rescue after an accident . The upper-torso anchorages take the form of a bracket on the roof-height crossbar formingpart of the central bulkhead.The team from the Technical University of Aachen, led by Professor Jurgen Helling, was responsible for most of the Uni-Car chassis (the brakes were done in Stuttgart).The chassis has all-independent suspension with automatic level control at the rear end, four-wheel disc brakes with ABS antilock, and recirculating-ball, low-energy-loss power steering. The level control is not just a comfort feature, but plays a part in the aerodynamics because the body attitude can affect the air flow. Responsibility for the engine tested with the Stuttgart team. They subcontracted with the big truck and engine makers of Munich, M.A.N. to build a 2.5-liter, four-cylinder diesel engine. It is turbocharged and delivers 98 hp. Fully encapsulated in its compartment, its noise pollution is insignificant. Because of the engine dimensions and the lack of width between the front wheel housings, it became impossible to mount it transversely as had been the original intention. Instead it was mounted longitudinally , and tilted at 45 degrees to the right to avoid putting bulges in the hood.The four universities agreed that with a front-mounted engine, it is logical to drive the front wheels even in a vehicle of this type and size. The transmission was Aachen’s task, and the choice fell on an experimental stepless drive under development by Van Doorne (Transmatic).Tests with the four prototypes assemble at the Darmstadt Technical University began early in 1982. The Uni-Car vastly surpassed its top-speed target—reaching 120-125 mph without difficulty. The acceleration target also was comfortably met. But the fuel economy? Considering the weight and payload capacity of Uni-Car, it is outstanding. At a constant 56 mph it gives 51mpg. Cruising at 74.5 mph it gives 39 mpg. And in the urban driving cycle it is a real winner at 30 mpg. Professor Bert Breuer at Darmstadt is pleased with the results, so far, and foresees two important consequences of this work. First, he looks forward to a greater readiness in the automobile industry to accept new technology from academic sources.Second, he expects the Uni-Car to generate more interest in auto engineering at the high-school level and bring in higher numbers of engineering students to the universities.附录学术角度的汽车研究从1979年10月到到1981年12月来自德国西部四所技术型大学的35个学生工程师和结构设计生利用全职时间创作了一辆研究型汽车。