Wednesday, February 29, 2012

Aerodynamics and the Automobile -- a Brief History Concerning the Path of Least Resistance

Streamlining and the Chrysler “Airflop”

As articulated previously, James Flink’s argument concerning technological stagnation during the interwar years is open to revision. For example, James Newcomb has argued that in terms of shape and design, the 1930s “represent a period of the most pronounced transition in automobile styling.”15 Newcomb argues that beginning with the1931 Reo Royale and the Chrysler Airflow, rounder, smoother, and more flowing shapes gradually were introduced, and that this was due to cultural constructs that emphasized security and togetherness at the expense of individualism. In sum, it was a shift in values tied to a Depression-era culture in transition that became expressed in the way cars looked. Consequently, the automobiles of 1940 in no way resembled the automobiles of 1929, just as the America of 1940 was far different than that prior to the Great Depression.
One prominent example illustrating Newcomb’s argument is the story of the development of the Chrysler Airflow and work in streamlining and aerodynamics in general that occurred in the automobile industry. Throughout the 1920s and 1930s, there was considerable enthusiasm for aviation, and some of it spilled over into automotive areas. Indeed, the relationship between the automobile industry and aviation remains to be studied beyond superficialities. As previously mentioned, the dashboard of the Cord 810 resembled that found in aircraft of the day. Supercharging, developed at Wright Field in Dayton, Ohio, was installed in 1930s Mercedes and Auburn-Cord-Duesenberg models. But the rise in interest in automobile aerodynamics was also due to increases in engine size and horsepower, coupled with improved roads. The drag of a vehicle was responsible for both lower top speeds and higher fuel mileage.
One of the first individuals to explore the aerodynamics of the automobile beyond a theoretical discussion was Edmund Rumpler, who constructed his Tropfenwagen (a car the shape of a water drop) in 1921.16 The Tropfenwagen can be translated as teardrop car, or raindrop car. Rumpler’s idea was that a falling drop of liquid was nature’s perfect airfoil design. As a drop fell, it would react to the pressure around it, and in so doing, its contour minimized wind resistance or drag. Only a limited number of these vehicles were built in 1921 and 1922, and then Rumpler sold the patents to the Benz firm. A surviving example of this historical curiosity can be found in the Technical Museum in Munich.
It is unclear what if any influence Rumpler had on the thinking of American automobile engineers, but technical articles appearing in the 1930s suggest that Paul Juray’s work was noticed and carefully studied in the U.S.17 The Hungarian-born Jaray was chief of the development department of the Zeppelin Airship works between 1914 and 1923. During the spring of 1921 he studied air flow passing around car bodies by using one-tenth scale wood models at the Zeppelin facility in Friedrichshafen, Germany. Jaray concluded that the vertical longitudinal section of a car was most important, and that it must be designed in such a way as to guide the air flow up and over the car in the front and down in the rear in such a manner that minimizes turbulence.
Others were thinking along similar lines during the late 1920s, and certainly one important figure was that of Carl Breer. As previously discussed, Breer, along with Owen R. Skelton and Fred Zeder, were known as the Three Musketeers at Chrysler Corporation during the 1920s. The three had formed a consulting engineering firm in 1921 after working for at time at Studebaker, and it was then that they caught the attention of Walter Chrysler. In 1924 they were instrumental in designing the Chrysler Model 70. As the story goes, Breer conceived of the Airflow concept while driving to his summer home in 1927. Traveling near Selfridge airfield, he spotted what he first thought was a flock of geese flying overhead, only to find it was a squadron of Army Air Corps planes on maneuvers. Aviation was on the minds of many Americans in 1927, as it was in May of that year that Charles Lindbergh flew solo across the Atlantic, and a new era of commercial aviation was just beginning. At any rate, this insight, and his playful inquisitiveness involving the forces of air resistance to an arm extended outside his car’s window led Breer to ponder ideas that were being discussed much of the time, namely that of form following function that had roots in the writing and architectural work of Louis Sullivan and his far more famous pupil, Frank Lloyd Wright. The question that remained in 1927 was “Why were aircraft becoming more streamlined while cars remained little more than boxy carriages?”
Approaching the problem scientifically, Breer went to William Earnshaw, an engineer at a research laboratory in Dayton, Ohio, and provided him with a car for making measurements of air-pressure lift and distribution. He also talked with Orville Wright, who assisted Earnshaw in designing a small wind tunnel where Breer subjected various scale models consisting of blocks of different shapes to aerodynamic analysis. With the addition of smoke, airflows passing around the models could be studied in the wind tunnel. As Earnshaw discovered from these experiments, areas of lower pressure formed behind the model, and higher pressures in the front. By rounding the front of the design and tapering the rear, streamlining was achieved.18
Before long, Walter Chrysler became interested, and approved construction of a much larger wind tunnel at Highland Park, Michigan, where over the next three years researchers tested hundreds of shapes, plotted eddy curves, noted turbulence, checked wind resistance, and calculated drag numbers.19
In addition to Chrysler engineers, there were others working on streamlining at this time. Most significantly, Amos E. Northrup, who worked for the Murray Body Company, designed the 1932 Blue Streak Graham with its enclosed fenders and radiator cap under the hood. A few others had more radical solutions, especially Buckminster Fuller with his Dymaxion car.20
Fuller, one of the true design geniuses of the twentieth century, is better known for his geodesic dome structure that was first proposed in 1949. In 1928, during a period of intense study, Fuller wrote a 2,000 page essay he called 4-D, and it was from the ideas articulated in this essay that the Dymaxion car emerged. Fuller designed his streamlined automobile in an abandoned Locomobile factory located in Bridgeport, Connecticut. The first Dymaxion was produced in 1933 from plaster models, and demonstrated at the Chicago Century of Progress World’s Fair. It was a gleaming, aluminum bullet-shaped object powered by a standard Ford V-8, and it was capable of going 115 mph. It brought together submarine and dirigible shapes, and there was nothing like it on the road. In this car the driver sat in the front, and there was no long hood. Shatterproof aircraft glass wrapped around the front, and sticking through the roof was a rear periscope. It was a low-slung vehicle that resembled a wingless fish and rode on just three wheels, two in the front and one in the rear. The two front wheels provided traction and braking and the rear steering. So many new ideas went into that transport: front wheel drive, air-conditioning, recessed headlights, and a rear engine. But an unfortunate accident killed the novel vehicle, even though it was not its fault, and its major idea, streamlining, was captured by the 1934 Chrysler Airflow.
In the six years that Breer and his team spent on the Airflow project, many trial and error experiments were performed that discovered some of the practical the rules of aerodynamics. One of the conclusions suggested a modified teardrop shape that allowed for a windshield and hood.21 The Airflow was an “engineers car,” with a conventional front engine rear and drive layout, but with some important modifications. Its engine was moved some 20 inches ahead of its normal position, front end styling characterized by a short curved nose, and an integral trunk. The fuel tank and radiator were now concealed. Inside, the center latch doors were chair-height seats in a vast, spacious interior. Riders sat at almost the center of the car's balance, producing an effect described in one brochure as “Floating Ride.” Indeed, “Floating Ride” was the consequence of Breer’s insights concerning the natural rhythms of the human body and the periodic oscillations that automobiles developed because of spring height. “No matter whether you are sitting in the front seat or the back, you can relax completely and utterly . . . you can ride comfortably amidships . . . experience no bumping, bouncing or vibration of any kind. The bumps seem to flow under the car without reaching you.” Also missing from the Airflow was the typical wood and steel composite body common to virtually all other cars of the period. In its place was one complete unitized steel unit “built like a modern bridge.” Streamlining was thus achieved not only on the outside of the car, but structurally as well. Box girders ran longitudinally up from the front and were joined with vertical and horizontal members to create an exceptionally strong structure, supposedly 40 times more rigid than the conventional frame and body. With the rear seat moved 24 inches inward, and the engine now positioned immediately above the front axle, driver and passengers no long experienced the same levels of fatigue as those riding in traditionally-designed vehicles.
For all of the Airflow's virtues, many buyers just couldn't ignore its new shape. In retrospect, it was probably too different for the general public to accept. The most controversial elements were probably the rounded snout with its waterfall grill, plus slabbed sides and the spatted rear wheel openings. After its introduction in 1934 and public criticisms, modifications were made to the 1935, ‘36 and ‘37 designs, including changing the shape and size of the grill to the point where by the end of the production run, it appeared to take on a conventional appearance.22
Despite these attempts to earn public acceptance, the critics were unforgiving and unrelenting. Industrial designer Henry Dreyfuss claimed that the Airflow was a “case of going too far too fast.” Frederick Lewis Allen, editor of Harper's Magazine, described it as being “so bulbous, so obesely curved as to defy the natural preference of the eye for horizontal lines.” Because of lengthy retooling delays, the car was late coming off the line and there were rumors of it being a lemon. GM didn't help by orchestrating a smear campaign and introducing its own turret-top all steel roof automobiles in 1935. And certainly early models were plagued with flaws, as line workers had difficulty making this very new kind of car.
Chrysler responded with publicity stunts like that of Citroen where a car was dropped off a 110-foot cliff. The Airflow’s doors opened easily; it then started under its own power and was driven away. Beginning in 1935, Chrysler made outward design changes and entered the car in various endurance motor sport events. But the damage was done, and the cars would not sell. Beginning with only 12,000 units sold in 1934, the numbers continued to slide though 1937 before it was discontinued after 1938. More conventional models and a conservatively revised Airflow design called Airstream saved the company, but the whole episode is a case study in what rumors will do to undermine a technologically advanced product. From innovative leader to conservative follower, Chrysler emerged from the Airstream episode badly shaken, reluctant to take on major changes given what could happen. Throughout the 1940s, and indeed into the 1950s Chrysler was content to follow GM designs, the third of the Big Three. Chrysler’s executives were well aware that it could be trampled by the large paws of GM if it went in too bold a technological direction.
The story of aerodynamics and the automobile industry during the 1930s had a happier ending at the Ford Motor Company. It was at Ford during the late 1930s that John Tjaarda, a Dutch-born designer who had studied aerodynamics in England and served in the Dutch air force, designed the Lincoln Zephyr. The Lincoln Zephyr’s drag coefficient was lower than that of the Airflow, as was its weight. Dr. Alexander Klemin, one of the designers of the Airflow, had miscalculated and made the Airflow’s body twice as strong as it had to be.
Drag and aerodynamics were for the most part ignored in the U.S. even after World War II, the one exception being the abortive Tucker of the late 1940s. In Europe, however, car companies that included Citroen, Volkswagen, and Fiat did pay attention to aerodynamics. It was only after the 1973 fuel shock that computer-aided design and computer-aided engineering were harnessed to improve the streamlining of autos, since fuel efficiency is intimately connected with drag. Thus, it was 40 years after Carl Breer at Chrysler had made the bold move to study aerodynamics at Chrysler that the industry caught up.23 In the process, the engineer and the stylist were now together in terms of their functions, and thus the stylist of old, artists the likes of Harley Earl, gave way to a new type of professional in the auto industry working in the 1980s.


  1. Thanks for sharing history regarding this information and quite interesting for car dealers to dealership especially in cars like Chrysler.
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  2. 参考になりました!ありがとうございます!