A teardrop trailer is an aerodynamically shaped semi-trailer with a curved-roof that differs in shape from the traditional rectangularly shaped trailer. The trailer is meant to be paired with a compatibly designed tractor unit leading to greater fuel efficiency of the tractor-trailer combination. As such, the "teardrop" phrase refers to the entire combination, not just the trailer. The curved shape of the roof decreases aerodynamic drag by smoothing airflow over the top, thus improving fuel efficiency.
One operator has reported the trailers save 2% in fuel in service that included significant low speed delivery operation and 5% in higher speed long-haul operation. [1]
Another factor improving airflow is the gap between the tractor and trailer is minimized to lessen the amount of turbulence created by air flowing into the gap. [1]
Teardrop trailers are only available in the United Kingdom and manufactured by one company, Don-Bur Trailers & Bodies Ltd which has patented the design. The manufacturer claims they can save 11.3% in fuel. [1]
The design echos streamlined shapes used in submarines, automobiles and camping trailers. The first streamlined car was the Tropfenwagen introduced in 1921, named after its teardrop shape (the literal translation from German is "drop car").
A study of trucking fleets in North American found that improving trailer aerodynamics was the least used method for improving fuel efficiency. Improving tractor aerodynamics and using low rolling resistance tires were adopted at much higher rates. [2]
The trailers have been used in the United Kingdom for several years by various operators. Deutsche Post DHL operates over 1,100 in the UK and was the first operator in continental Europe; it announced in 2014 that it would use the trailers in France and Germany. [3]
A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is expressed as its lift-to-drag ratio. The lift a wing generates at a given speed and angle of attack can be one to two orders of magnitude greater than the total drag on the wing. A high lift-to-drag ratio requires a significantly smaller thrust to propel the wings through the air at sufficient lift.
A velomobile ; velomobiel, velo, or bicycle car is a human-powered vehicle (HPV) enclosed for aerodynamic advantage and/or protection from weather and collisions. Velomobiles are similar to recumbent bicycles, pedal go-karts and tricycles, but with a full fairing and are not to be confused with purpose-built mobiles for racing or speed records fully faired vehicles with two wheels, generally called streamliners. Streamliners have set many speed and distance records.
Automotive aerodynamics is the study of the aerodynamics of road vehicles. Its main goals are reducing drag and wind noise, minimizing noise emission, and preventing undesired lift forces and other causes of aerodynamic instability at high speeds. Air is also considered a fluid in this case. For some classes of racing vehicles, it may also be important to produce downforce to improve traction and thus cornering abilities.
In aeronautics, wave drag is a component of the aerodynamic drag on aircraft wings and fuselage, propeller blade tips and projectiles moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects, and tends to present itself as a sudden and dramatic increase in drag as the vehicle increases speed to the critical Mach number. It is the sudden and dramatic rise of wave drag that leads to the concept of a sound barrier.
In aerodynamics, the lift-to-drag ratio is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under given flight conditions. The L/D ratio for any given body will vary according to these flight conditions.
In aerodynamics, lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, is an aerodynamic drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings or a lifting body redirecting air to cause lift and also in cars with airfoil wings that redirect air to cause a downforce. It is symbolized as , and the lift-induced drag coefficient as .
A Kammback—also known as a Kamm tail or K-tail—is an automotive styling feature wherein the rear of the car slopes downwards before being abruptly cut off with a vertical or near-vertical surface. A Kammback reduces aerodynamic drag, thus improving efficiency and reducing fuel consumption, while maintaining a practical shape for a vehicle.
A spoiler is an automotive aerodynamic device whose intended design function is to 'spoil' unfavorable air movement across the body of a vehicle in motion, usually described as turbulence or drag. Spoilers on the front of a vehicle are often called air dams. Spoilers are often fitted to race and high-performance sports cars, although they have become common on passenger vehicles as well. Spoilers are added to cars primarily for styling purposes and either have little aerodynamic benefit or even worsen the aerodynamics.
A V formation is a symmetric V- or chevron-shaped flight formation. In nature, it occurs among geese, swans, ducks, and other migratory birds, improving their energy efficiency, while in human aviation, it is used mostly in military aviation, air shows, and occasionally commercial aviation.
The Chrysler Airflow is a full-size car produced by Chrysler from 1934 to 1937. The Airflow was the first full-size American production car to use streamlining as a basis for building a sleeker automobile, one less susceptible to air resistance. Chrysler made a significant effort at a fundamental change in automotive design with the Chrysler Airflow, but it was ultimately a commercial failure due to a lack of market acceptance and controversial appearance.
A mudflap or mud guard is used in combination with the vehicle fender to protect the vehicle, passengers, other vehicles, and pedestrians from mud and other flying debris thrown into the air by the rotating tire. A mudflap is typically made from a flexible material such as rubber that is not easily damaged by contact with flying debris, the tire, or the road surface.
The Rumpler Tropfenwagen was a car developed by Austrian engineer Edmund Rumpler.
The Czechoslovakian Tatra 77 (T77) is one of the first serial-produced, truly aerodynamically-designed automobiles. It was developed by Hans Ledwinka and Paul Jaray, the Zeppelin aerodynamic engineer. Launched in 1934, the Tatra 77 is a coach-built automobile, constructed on a platform chassis with a pressed box-section steel backbone rather than Tatra's trademark tubular chassis, and is powered by a 60 horsepower (45 kW) rear-mounted 2.97-litre air-cooled V8 engine, in later series increased to a 75 horsepower (56 kW) 3.4-litre engine. It possessed advanced engineering features, such as overhead valves, hemispherical combustion chambers, a dry sump, fully independent suspension, rear swing axles and extensive use of lightweight magnesium alloy for the engine, transmission, suspension and body. The average drag coefficient of a 1:5 model of Tatra 77 was recorded as 0.2455. The later model T77a has a top speed of over 150 km/h (93 mph) due to its advanced aerodynamic design which delivers an exceptionally low drag coefficient of 0.212, although some sources claim that this is the coefficient of a 1:5 scale model, not of the car itself. Recent article confirmed the Tatra 77/77a drag coefficient for real full-size car as 0.36.
The SmartWay Transport Partnership is a business organization administered by the United States government and designed to encourage businesses to manage logistics in an environmentally responsible way. The program was formed in 2004, and is administered by the United States Environmental Protection Agency (USEPA) and is housed with the USEPA's Office of Transportation and Air Quality (OTAQ) - Transportation and Climate Division (TCD). SmartWay aims to voluntarily achieve improved fuel efficiency and reduce environmental impacts from freight transport. SmartWay currently has approximately 600 member businesses, membership is voluntary. The organization provides incentives and recognition for top performers to encourage continued improvement.
An adaptive compliant wing is a wing which is flexible enough for aspects of its shape to be changed in flight. Flexible wings have a number of benefits. Conventional flight control mechanisms operate using hinges, resulting in disruptions to the airflow, vortices, and in some cases, separation of the airflow. These effects contribute to the drag of the aircraft, resulting in less efficiency and higher fuel costs. Flexible aerofoils can manipulate aerodynamic forces with less disruptions to the flow, resulting in less aerodynamic drag and improved fuel economy.
The drag coefficient is a common measure in automotive design as it pertains to aerodynamics. Drag is a force that acts parallel to and in the same direction as the airflow. The drag coefficient of an automobile measures the way the automobile passes through the surrounding air. When automobile companies design a new vehicle they take into consideration the automobile drag coefficient in addition to the other performance characteristics. Aerodynamic drag increases with the square of speed; therefore it becomes critically important at higher speeds. Reducing the drag coefficient in an automobile improves the performance of the vehicle as it pertains to speed and fuel efficiency. There are many different ways to reduce the drag of a vehicle. A common way to measure the drag of the vehicle is through the drag area.
A motorcycle fairing is a shell placed over the frame of a motorcycle, especially racing motorcycles and sport bikes, to deflect wind and reduce air drag. The secondary functions are the protection of the rider from airborne hazards and wind-induced hypothermia and of the engine components in the case of an accident. A motorcycle windshield will usually be integrated into the design of the fairing.
The wing configuration of a fixed-wing aircraft is its arrangement of lifting and related surfaces.
The KenworthT600 is a model line of conventional-cab trucks that were produced by the American truck manufacturer Kenworth from 1984 to 2007. Distinguished by its aerodynamic sloped hood, the T600 was a Class 8 truck, typically sold in semitractor configuration.
Semi-trailer aerodynamic devices are devices affixed to semi-trailers, for the purpose of reducing aerodynamic drag caused by air turbulence. The two major types of device in use are trailer skirts, affixed to the underside of trailers, and trailer tails, affixed to the rear. Several such devices have been recognized by the U.S. Environmental Protection Agency's SmartWay Transport Partnership, making them eligible for funding under the Diesel Emissions Reduction Act.