Aerodynamics of Vehicles and Airplanes, and Hydrodynamics of Ships - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 115

7.4.1 Aerodynamics of Vehicles
There are three approaches with different reduction potentials for fuel consumption
and exhaust gas emissions:
• The use of smooth and aerodynamically optimal surfaces;
• The introduction of new technologies to achieve low air resistance; and
• Combining lightweight construction materials which have comparable or better
surface characteristics than conventional materials such as steel and aluminum.
The power to overcome air resistance increases roughly with the cube of the
speed and the energy required per unit distance is roughly proportional to the
square of the speed. The power needed to overcome the rolling resistance is also a
decisive factor, particularly at lower speeds and higher gross weights. At very low
speeds, the dominant losses are from internal friction.
7.4.2 Aerodynamics of Airplanes
Redesigning the fuselage and the wings has the greatest potential for decreasing
aerodynamic resistance. There are two main research emphases for improved
aerodynamics:
• Improvement of existing airplanes and their systems; and
• Long-term development of completely new concepts for the next generations of
commercial aircraft.
The general use of winglets can save fuel on older as well as on new aircraft
because resistance goes down and fuel consumption decreases.
Radically new concepts for commercial aircraft, like a blended wing and body
airplane would aerodynamically deliver substantially better lift, but there are also
unsolved problems which will prevent the fulfillment of the concept in the next
decades. Laminar flow can be partly realized with artificial vacuum at a very high
cost level.
7.4.3 Hydrodynamics of Ships
Hydro- and aerodynamics plays a decisive role in the construction of ships and
determination of operating costs, similar to other sectors of transportation. Saving
fuel in ships requires:
• In the construction phase
- Increasing the vessel's size for higher fuel efficiency;