**8. Conclusions**

front of aircraft). This solution could be applied in future at the new supersonic jet

The supersonic passenger aircraft Concorde Mark 2 filled in patent [33] by Astrium SAS and European Aeronautic Defense and Space Company would be capable to fly with 4023 km/h (1118 m/s) transporting 20 passengers or 3 tons of cargo on a distance of 8851 km. The duration of travel between London and New

The cathodes are sharp Wolfram needles placed along a rod, which is fixed in the tip of aircraft nose and along the wing LE (**Figure 18**). The anodes are thin copper sheets, which are fixed by the aircraft nose and pressure/suction sides of wing. Obviously, the anodes and cathodes are electrically insulated by the aircraft frame. [Note: In **Figure 18**, the dimensions of cathodes are exaggerated for clarity.

A high potential electrical source (thousands of volts) is connected to the cathodes and anodes by means of an electrically insulated wire network. When the electrical high voltage source is connected to the wire network, a high number of

[Note: This type of discharge differs by the type of discharge presented in Chapter 6.1 where positive ions are generated through loosing of electrons by atoms due to the primary electrons generated by cathode and accelerated by the potential

The released electros are spread in the air stream without generating a significant number of ions because the distance between cathodes and anodes is much

The quantity of electrons injected in air stream is very high due to the high number of cathodes and their sharpness and the high potential applied. After detaching the sharp cathodes, the electrons move together with the oxygen and nitrogen molecules to the shock wave, which has the semi-angle β given by Eq. (1) (in the case of oblique shock wave). The injected electrons can be free among the oxygen and nitrogen molecules or can be temporary attached by a part of molecules

In this way, the shock wave will be composed of neutral nitrogen and oxygen molecules, free electrons and temporary negative molecules. The shock wave is

*New solution proposed for dispersing of shock wave through injection of electrons in surrounding airflow by*

called Concorde Mark 2 (**Figure 18** [32]).

*Environmental Impact of Aviation and Sustainable Solutions*

Actually, they have the dimension of a usual sewing needle].

electrons are released through the sharp tips of the cathodes.

York would be of 1 hour.

The system works as follows:

difference between the cathode and anode].

larger than in the case of plasma actuators.

**Figure 18.**

**126**

*sharp electrodes [16, 32, 33].*

generating in this way temporary negative molecules.

The new solutions presented in this chapter use dispersion of shock wave through mechanical or electrical means. These solutions are alternatives for "shaping" solution or using of very thin fuselage.

Following the shock wave dispersion, the resulting sonic boom is spread on a much larger area at the ground level, as a consequence, the air in the 'N'shock wave is much smaller than in the normal case.

Low amplitude mechanical vibration of aircraft nose, wing LE, and horizontal empennage LE leads to shock wave dispersion.

A first technological possibility is vibrating a membrane, which is stretched over aircraft nose, wing LE, and horizontal empennage LE. In this case, the membranes are actuated by sonic pulses propagated through a hydraulic liquid.

A second solution is vibrating of elastic fairings placed over the aircraft nose, wing LE, and horizontal empennage LE.

Injection of electrons in front of aircraft cone/wing/empennage could be a productive technology for reduction of sonic boom impact on community in the case of supersonic/hypersonic passenger aircraft and business jets.

The cathode (negative electrode) is composed of multiple needles of Wolfram placed on a rod, which is fixed in the tip of aircraft cone or placed along the leading edges of wing and horizontal tail.

The anode (positive electrode) is composed of multiple copper plates glued by aircraft nose and wing suction/pressure sides.

The cathodes and anodes are electrically insulated by the aircraft frame.

The electrons released by the sharp cathodes in the airstream are free or can be attached by oxygen and nitrogen molecules forming temporary negative molecules.

When arriving in the shock wave, these temporary negative molecules and free electrons repel each other dispersing the shock wave. As a result, the impact of "N" shock wave at ground level will be much reduced.

Experiments should be initiated for evaluation of this possible effect. Voltages of many thousands of V should be used because the number of electrons injected in the air stream depends on the value of potential difference between the cathodes and anodes.
