Cars without a windshield have an advantage in controlling airflow using aerodynamic principles. However, these vehicles are not suitable for everyday use.
The Importance of Windshields
The windshield serves a very specific purpose – to prevent wind and dust from entering the eyes of the people inside the vehicle. Surprisingly, windshields were not a mandatory component in cars when they first appeared on the market. In the past, windshields were primarily ordinary glass panels sold as accessories rather than standard equipment.
Windshields were equipped as optional accessories in early cars.
This was because, in the early days of the automotive industry, engines were still in their infancy, moving at much lower speeds than today, thus causing less wind and dirt to disturb users. However, these initial glass panels were very brittle and would shatter into large, sharp pieces upon impact, posing significant danger to passengers. This led to the development of tempered glass and laminated glass.
Tempered glass breaks into small, blunt pieces upon impact, which is why it is used for side windows. Laminated glass, on the other hand, consists of a layer of plastic sandwiched between two layers of glass, which, when broken, still retains its structure due to the interlayer, providing safety for passengers and is commonly used for windshields.
In addition to protecting passengers from external elements, windshields serve two additional functions.
- First, they form a part of the car’s structure. This means they share some of the impact forces in the event of an accident, along with other components of the vehicle frame.
- Second, they reduce drag and improve fuel efficiency.
The windshield is the first barrier against external elements such as strong winds, dirt, insects, and flying debris when the vehicle is moving at high speeds. Thanks to the windshield, drivers and passengers are protected from these harmful agents, ensuring safety for their eyes, skin, and respiratory systems.
Why Do Some Cars Not Have Windshields?
If windshields play so many roles, then removing them from cars might sound like a technically foolish act. However, some limited-edition and expensive models lack a windshield.
This idea originated from small Italian boats called barchettas. This nickname is also used in the automotive industry, where it represents convertible sports cars. A distinctive feature of barchetta-style cars is the absence of a full windshield; instead, they have a small windscreen to partially protect the driver from weather elements.
Windshields made from special materials with high impact resistance help protect the driver and passengers in the event of an accident. While windshields can break, they do not shatter into sharp pieces, reducing the risk of injury to those inside the vehicle.
However, over time, these cars have completely eliminated windshields. To ensure passenger comfort and driving capability, the body panels are designed to control airflow around and through the cabin.
Although this design has various proprietary names from different manufacturers, the basic concept remains the same.
How Is Air Controlled in Windshield-less Cars?
In fact, when driving older barchetta-style cars, drivers should wear goggles or helmets with visors to protect themselves from incoming winds. However, for modern barchettas, this is unnecessary, as they are designed to optimize airflow and direct it through air ducts at the front of the vehicle.
In reality, no standard vehicle is manufactured without a windshield. The windshield plays a crucial role in safety and driving experience, making the absence of this component a violation of traffic safety regulations in most countries.
When a car moves forward, it cuts through the wind. Part of this wind is directed into air ducts, while the rest flows over the hood.
The air ducts are designed to channel high-speed airflow and create an angle for it to exit from the car’s hood. This angle is typically vertical or directed away from the driver. This air exits the duct, forming a barrier that obstructs high-speed airflow across the hood.
Some race cars are designed to optimize speed and aerodynamic performance may utilize a closed cockpit or helmet instead of a windshield. However, these vehicles are typically only used in controlled racing environments with other safety measures to protect the driver.
The result of this interaction is a stream of air flowing over the driver’s head similarly to airflow through a windshield. When this air reaches the cabin, it will be further directed through open channels to separate the turbulent component of the air from the laminar component.
Illustration of testing in a wind tunnel for windshield-less cars.
Barchettas are also equipped with wind deflectors that disrupt airflow in high-pressure areas to create low pressure. This improves airflow in the desired direction. Furthermore, they are also equipped with wings that generate downforce to keep the car grounded at high speeds.
However, due to the lack of conventional safety features, windshield-less cars are often prohibited from operating on public roads in many countries.
