**6. The supersonic European business and passenger aircraft**

The European community intends to enter the competition for manufacturing of the future supersonic business and passenger aircraft. The future European supersonic aircraft could have a normal design except the nose and LE of wing and horizontal empennage. In a more sophisticated case, even the vertical empennage and the entry in engine admission device can be vibrated (**Figure 15** [26]). In the indicated areas, vibrating membranes or fairings should be mounted for shock wave dispersion.

### **7. Electrical solutions for dispersing of shock wave**

Intense research is taking place in our days for dispersion of shock waves generated by aircraft through electrical means. It was observed that the so called plasma actuators consisting of high voltage electrodes (cathodes and anodes) have effect on airflow through air ionization. At present plasma actuators are researched both for noise reduction in the fan ducts of jet engines and for dispersion of shock wave for mitigation of its effects at ground level.

#### **7.1 Using of plasma actuators for dispersion of shock wave**

In some preliminary experiments, plasma actuators (**Figure 16**) were used for increasing of semi-angle β of conical shock wave (**Figure 16b**) [31].

Taylor-Maccoll theory). The potential difference between the two electrodes is of

In the presented case, positive ions are generated when atoms are losing an electron. An avalanche effect is taking place when electromagnetic energy is ionizing more atoms (this effect is visible as a blue light). Applying of such a solution seems to be difficult in the case of real aircraft because the electrical discharge can

On the other hand, the aircraft nose and wing LE have a large area, and it is hard to believe that such a system, which was tested at low scale can be applied at the

The new possible solution proposed in this paper is based on a massive injection of electrons through very fine and sharp electrodes in the upstream of air stream (in

**7.2 A new possible solution for shock wave dispersing through injection of**

**electrons in surrounding airflow through sharp electrodes**

become thermal destroying in this way the electrode surfaces.

several thousands of volts.

*Detaching of shock wave for a given potential [31].*

**Figure 16.**

**Figure 17.**

**125**

*Dispersing of shock wave using plasma actuators [31].*

*Sonic Boom Mitigation through Shock Wave Dispersion DOI: http://dx.doi.org/10.5772/intechopen.85088*

large scale of an aircraft.

When the potential difference between two electrodes (cathode, anode) (**Figure 16a**) is increasing progressively, the cone semi-angle β (**Figure 16b**) is increasing to a critical value βcr when the shock wave becomes detached (**Figure 17**,

#### **Figure 15.**

*A possible European supersonic business jet/passenger aircraft using vibrating surfaces for shock wave dispersion [26].*

*Sonic Boom Mitigation through Shock Wave Dispersion DOI: http://dx.doi.org/10.5772/intechopen.85088*

A sonic generator sends pressure pulses to the main duct containing hydraulic liquid. The pressure pulses propagate with high speed to the liquid existent between membrane and wedge. As a result, membrane surface is bending and wedge angle

The experimenting procedure is similar to that presented at point 4.1: Firstly, the shock wave is observed for various speeds when sonic pulses through the main duct

After that, sonic pulses are sent through the main duct with hydraulic liquid, and

For every measurement, the shock wave should have a variable taper and thick-

The experiments using the test equipment no. 2 are very useful because they

The European community intends to enter the competition for manufacturing of the future supersonic business and passenger aircraft. The future European supersonic aircraft could have a normal design except the nose and LE of wing and horizontal empennage. In a more sophisticated case, even the vertical empennage and the entry in engine admission device can be vibrated (**Figure 15** [26]). In the indicated areas, vibrating membranes or fairings should be mounted for shock wave dispersion.

Intense research is taking place in our days for dispersion of shock waves generated by aircraft through electrical means. It was observed that the so called plasma actuators consisting of high voltage electrodes (cathodes and anodes) have effect on airflow through air ionization. At present plasma actuators are researched both for noise reduction in the fan ducts of jet engines and for dispersion of shock wave for

In some preliminary experiments, plasma actuators (**Figure 16**) were used for

When the potential difference between two electrodes (cathode, anode) (**Figure 16a**) is increasing progressively, the cone semi-angle β (**Figure 16b**) is increasing to a critical value βcr when the shock wave becomes detached (**Figure 17**,

*A possible European supersonic business jet/passenger aircraft using vibrating surfaces for shock wave*

with hydraulic liquid are not present. Position of shock wave is schlieren

the shock wave is schlieren photographed for the same speeds as before.

**6. The supersonic European business and passenger aircraft**

**7. Electrical solutions for dispersing of shock wave**

**7.1 Using of plasma actuators for dispersion of shock wave**

increasing of semi-angle β of conical shock wave (**Figure 16b**) [31].

photographed for various values of Mach number.

*Environmental Impact of Aviation and Sustainable Solutions*

ness depending on frequency and Mach number.

simulate very close the real case on aircraft.

mitigation of its effects at ground level.

**Figure 15.**

**124**

*dispersion [26].*

increases with Δα.

**Figure 16.** *Dispersing of shock wave using plasma actuators [31].*

**Figure 17.** *Detaching of shock wave for a given potential [31].*

Taylor-Maccoll theory). The potential difference between the two electrodes is of several thousands of volts.

In the presented case, positive ions are generated when atoms are losing an electron. An avalanche effect is taking place when electromagnetic energy is ionizing more atoms (this effect is visible as a blue light). Applying of such a solution seems to be difficult in the case of real aircraft because the electrical discharge can become thermal destroying in this way the electrode surfaces.

On the other hand, the aircraft nose and wing LE have a large area, and it is hard to believe that such a system, which was tested at low scale can be applied at the large scale of an aircraft.
