Aerodynamics of Vehicles and Airplanes, and Hydrodynamics of Ships - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 111

modification with reinforcement of
the profile structure and development
and installation of electronic sensors

1 000 t less fuel consumption
per year, which is approximately 25 %
fuel reduction

integrated winglet

reduced noise

modification in approximately 25 days

variable profile curvature

more effective lifting system
by low velocity

Fig. 7.4 Wing of a middle distance airplane with raked wingtips

airplanes. The reduced aerodynamic resistance always leads to decreased fuel
consumption and exhaust gas emissions [ 11 ]. Development of a porous surface of
airplanes is a high risk technical challenge. Contamination by insects and debris
can significantly reduce the performance of laminar flow and increase maintenance
costs. Therefore more time is needed before it can be introduced [ 12 ].

7.3 Hydro- and Aerodynamics of Ships

The ship's fuel consumption depends on the function:
FC ¼ c R q w
2

v 2 S : ð 7 : 1 Þ

In the function c R is the resistance coefficient, q w the density of water, v the
speed of the ship and S the moistened surface. The resistance coefficient c R can be
relatively easily tested and exactly determined for cars and airplanes, but not for
ships because ships move through both the water and the air. The resistance is the
sum of both determining factors [ 13 ].
There are different basic types of approach to assess the hydrodynamic

resistance:

• Testing in a basin;
• Testing in wind tunnels; and
• Using a computer model [ 14 ].