Aerodynamics pioneers through today’s eyes

Škoda has been studying aerodynamics for longer than you may have thought. While air drag is reduced today by the use of sharp lines, the previous strategy used rounded shapes. What has changed over the years?

20. 5. 2024 Škoda World

Aerodynamics is one of the key issues in the development of new cars today. Drag has a major impact on fuel consumption and, in the case of electric cars, range per charge. But the quest for the most aerodynamic shapes is nothing new for the Czech carmaker.

Today’s aerodynamics experts invited Škoda Storyboard to the Škoda Museum to take a look at three special cars that blazed the aerodynamics trail many decades ago – the Škoda 935 Dynamic from 1935, the Škoda Popular Monte Carlo from 1937 and the Škoda Rapid OHV from 1940.

Naturally, the main focus was on how early designers approached a field where the goal is to reduce air resistance, make body curves elegant and get as close as possible to ideal streamlined shapes. Can any inspiration be drawn from 90-year-old solutions?

Three veterans that led the way in aerodynamics decades ago - Škoda 935 Dynamic, Škoda Rapid OHV a Škoda Popular Monte Carlo (from left).

“One paradoxical characteristic of cars up to the early 1930s that is both typical and interesting for us aerodynamicists is that they had less aerodynamic drag when going backwards than when going forwards! That’s because the front of the car was usually made up of several flat parts at right angles to the ground, such as the radiator, headlights, windscreen etc., and the transitions between them were very sharp, whereas the rear of the car was rounder. By the late 1930s, motorways were being built and driving was getting faster. Speed was becoming more important for customers and carmakers started trying to create teardrop-shaped aerodynamic shapes inspired by nature,” says Jan Jagrik, head of the aerodynamics development department.

Paradoxically, cars at the start of the 1930s tended to have better aerodynamic resistance going backwards than forwards.

Blinds then and now

“On the black Škoda Popular Monte Carlo coupé we see a tapering rear end with a fin to provide stability, as well as teardrop-shaped mudguards. The grilles in front of the headlights and radiator are prominent, and are designed to help air flow around what are essentially vertical headlight surfaces,” Jagrik says, describing the striking design.

Jan Jagrik, head of the aerodynamics development department, and the Dynamic 935 - a “streamlined” car designed with motorways in mind and with several aerodynamic features, such as rear wheel covers and a stabilising fin on the tapering rear.

According to his colleague, aerodynamics project manager Vojtěch Jakubec, the cars show an effort to tackle issues that are still being pursued today, albeit in a slightly different way, of course. “It’s precisely the flow detachment behind the rear of the car that we are still very much focused on today. Another issue is the wheels – the 935 Dynamic has its rear wheels covered, which is a real benefit to the aerodynamics. On the other hand, I don’t think they paid much attention to the underside of the floor back then, which is a very important focal point on cars today.”

So can the experts find elements on vintage cars that are still used today? Some, apparently, although the vast majority of solutions used ninety years ago simply aren’t applicable today. That’s mainly because of the present-day legislation. In the past, car’s behaviour in crashes wasn’t considered – there were no crash tests, there were no pedestrian protection regulations, cars could have all kinds of protruding parts, and there was no consideration of the view from the cab or the positioning of headlights.

Aerodynamics specialist Josef Šiman and the Škoda Popular Monte Carlo

“But on the Rapid, for example, we see a blind in front of the radiator that the driver could roll down when cooling wasn’t needed. The blind shielded the radiator so the air was not forced through, but flowed around the body – a path of less resistance. We still have this today in modern cars, but its design is of course completely different and it has automatic electronic controls. But the principle is the same,” explains aerodynamics specialist Josef Šiman.

The blind in front of the radiator grille on the Rapid, which the could lower if he didn’t need cooling.

Rapid in a tunnel

It may come as a surprise to some that wind tunnels began to be used to improve cars’ aerodynamics almost ninety years ago. Prague’s Czech Aerospace Research and Testing Institute had a wind tunnel as early as the 1920s, but there are no reports of its use for car manufacture in that decade. We do know, however, about the youngest of the three cars, the Škoda Rapid OHV “motorway” model. “There is a report in the company archives from 1938 about a 1:6 scale wooden model being tested in the tunnel in the research institute and being compared with a model of a car with a standard body.”

While today – put simply – body shapes are tweaked mainly by computer simulation and then checked in the wind tunnel, back then the wind tunnels were actually used to develop the bodies. “There was no other option than to have several alternative shapes in advance for parts of the car like the bumpers or mirrors, and to fit each in turn onto the model, see how the air flows around them, and then choose the best version – basically by trial and error. Gradually, clay models began to be taken into the tunnel and shaped on the spot by designers with scrapers – taking off a bit here and adding a bit more there. Thanks to the development of modern wind tunnels from about the 1980s onwards, and especially with the advent of computer simulations at the turn of the century, we now have much more information about the shapes being developed. Obviously, this makes the development of aerodynamics more efficient,” explains Jakubec.

Aerodynamics manager Vojtěch Jakubec and the Škoda Rapid OHV

You might be wondering how airflow was studied in the wind tunnel. Fine cotton wool was glued onto the bodywork at certain points, and the designers watched how it fluttered and in which direction at each of those points. Alternatively, smoke was used and its movement around the car was observed. That hasn’t changed to this day.

An aerodynamics masterclass

Now it’s time to take a closer look at the prototype of the aerodynamic Škoda 935 Dynamic sedan, which was unveiled at the 1935 Prague Motor Show. The three aerodynamics experts point out more interesting details. “Although the Dynamic and Popular cars are from a similar era, there is a marked difference in design. The different class of car and therefore the price no doubt played a big part in this. The most striking thing about the Dynamic is its teardrop-shaped silhouette with a tapering rear end, the cabin that gets narrower towards the rear and the covered rear wheels. Compared to the other cars, there’s one more thing: the engine is mounted in front of the rear axle, which allows the underside of the car to be almost flat all the way around, which isn’t possible with a front-mounted engine. There’s also an attempt to make the headlights as flush as possible with the nose and therefore to give the entire body a single line. There are no longer several separate teardrop shapes – bumpers, roof and so on. Instead, we can see the endeavour to make a single monoblock, one big teardrop shape. Note also the front wheels, which are not significantly pushed inside – the gap between the edge of the tyre and the mudguard is minimal. It’s an aerodynamics masterclass,” Šiman says with a smile.

View 5 photos

It is on the Dynamic that the principles of aerodynamics, which were as valid then as they are today, are most evident. “It’s about trying to have the airflow as close to the body as possible. And if the air does get forced away at some point, it’s best to have it defined by some distinct edge. That adhesion can be better realised with a teardrop design – we can see how the cross-section and shape of the car changes smoothly so that the air doesn’t actually have much reason to detach anywhere,” Jakubec says.

“I reckon it’s worth remembering how cars were actually built back then. There were no car designers at that time. Everything was designed by constructors who drew templates on drawing boards, so they designed the body shapes as well. You then had a craftsman who – if I can exaggerate a bit – sat at his bench and hammered a piece of metal into the shape of a bumper or a bonnet, tweaking it slightly according to his experience and feel so the end result was slightly different and maybe even a little bit better. The work was not as clear-cut as today. Shapes and lines emerged organically in the hands of the craftsmen, and it’s thanks to their skill and feel that the beautiful aesthetic shapes we admire to this day were created. They radiate emotion. It’s a lovely piece of history and good old craftsmanship,” says Jan Jagrik, head of the aerodynamics development department, paying home to his forebears.

“The aerodynamics tradition at Škoda really is ninety years old. That’s longer than many of today’s carmakers have existed. I am proud that our work here has such firm foundations,” he adds.

Today’s aerodynamics specialists can still take inspiration from the work of old bodywork artisans.