2
1 The Experimental Approach in Aerodynamic Design
Fig. 1.1 Forces acting on a flying vehicle (© Dassault Aviation)
could affect grounding of the vehicle at high-speed and creates unnecessary drag.
Here, we look for a zero or even negative lift when the goal is to turn at high speed,
mainly in Formula 1 race.
The drag determines the propulsive force to exercise to keep the vehicle moving.
This is an essential piece of information that determines fuel consumption. The side
force is one of the components playing an important role in the stability of the vehicle.
For example this could be the effect of a gust or a side wind on the handling of a car.
Aerodynamic moments are also critical for the stability of the vehicle or structures.
Earlier we introduced the notion of the centre of pressure variations which is the
point of application of the variations of aerodynamic forces. The relative positions
of the centre of pressure and the centre of gravity define the stability conditions.
In addition to controlling drag and lift, aerodynamic studies must also predict the
local forces exerted on the body, especially the pressure, in order to calculate the
deformations of the structure. The reciprocal influence between the structure, which
by deforming modifies the aerodynamic field, and the flow which therefore imposes
a varying load on the structure, is the origin of a fluid-structure interaction which can
lead to severe conditions like flutter. A famous example is the failure of the suspension
bridge of Tacoma which was triggered by a storm. This phenomenon, which is a
concern for most aerodynamic applications including compressor or turbine blades,
helicopter and wind turbine blades, brings us to the field of aeroelasticity.
Aeroacoustic deals with the interaction between aerodynamics and acoustics. The
main focus in this field is on reducing the noise emitted by the turbulent boundary
layer, the flow separations occurring on certain parts of the vehicle, the jets of the
reactors or even those generated by propellers, helicopter rotors and wind turbines.
Aerodynamic noise is also a concern for land vehicles, its level exceeding the rolling
1 The Experimental Approach in Aerodynamic Design
Fig. 1.1 Forces acting on a flying vehicle (© Dassault Aviation)
could affect grounding of the vehicle at high-speed and creates unnecessary drag.
Here, we look for a zero or even negative lift when the goal is to turn at high speed,
mainly in Formula 1 race.
The drag determines the propulsive force to exercise to keep the vehicle moving.
This is an essential piece of information that determines fuel consumption. The side
force is one of the components playing an important role in the stability of the vehicle.
For example this could be the effect of a gust or a side wind on the handling of a car.
Aerodynamic moments are also critical for the stability of the vehicle or structures.
Earlier we introduced the notion of the centre of pressure variations which is the
point of application of the variations of aerodynamic forces. The relative positions
of the centre of pressure and the centre of gravity define the stability conditions.
In addition to controlling drag and lift, aerodynamic studies must also predict the
local forces exerted on the body, especially the pressure, in order to calculate the
deformations of the structure. The reciprocal influence between the structure, which
by deforming modifies the aerodynamic field, and the flow which therefore imposes
a varying load on the structure, is the origin of a fluid-structure interaction which can
lead to severe conditions like flutter. A famous example is the failure of the suspension
bridge of Tacoma which was triggered by a storm. This phenomenon, which is a
concern for most aerodynamic applications including compressor or turbine blades,
helicopter and wind turbine blades, brings us to the field of aeroelasticity.
Aeroacoustic deals with the interaction between aerodynamics and acoustics. The
main focus in this field is on reducing the noise emitted by the turbulent boundary
layer, the flow separations occurring on certain parts of the vehicle, the jets of the
reactors or even those generated by propellers, helicopter rotors and wind turbines.
Aerodynamic noise is also a concern for land vehicles, its level exceeding the rolling