Reducing contrails during operation of aircraft

Abstract

A method is described for reducing contrails during operation of an aircraft (100, 100) having a heat engine 10. The method includes inducing a condensation of moisture contained in the exhaust gas (A) of the heat engine by mixing at least a portion of the exhaust gas with ambient air (U) of the aircraft as well as separating the condensed-out water on the aircraft. Also described is an aircraft (100, 100) having a heat engine (10). The aircraft includes at least one nozzle (30) which is adapted for conducting exhaust gas (A) from the heat engine of the aircraft at least partially into ambient air (U) of the aircraft and thus to produce a gas mixture, and at least one separator device (40) for separating condensed-out water from the gas mixture.

Claims

1. A method for reducing contrails during operation of an aircraft having a heat engine, the method comprising: inducing a condensation of moisture contained in the exhaust gas of the heat engine by mixing a proportion of the exhaust gas with a proportion of ambient air flowing around the aircraft during operation to create condensed-out water; separating the condensed-out water on the aircraft; and injecting the water resulting from the separating step into a combustion chamber of the heat engine or using the water resulting from the separating step to generate steam; wherein the separating includes electrostatic charging of water molecules in the exhaust gas and directing charged, condensed-out water droplets towards a complementary pole.

2. The method as recited in claim 1 wherein the mixing is at least partially performed on an outer surface of the aircraft, at least a portion of the ambient air flowing along the outer surface.

3. The method as recited in claim 1 further comprising drawing off separated water using a condensate pump.

4. The method as recited in claim 1 wherein the mixing takes place at least partially in a mixing channel in the aircraft, at least a portion of the ambient air flowing through the mixing channel.

5. The method as recited in claim 4 further comprising adjusting an inflow of ambient air into the mixing channel by influencing a variable inlet opening of the mixing channel.

6. An aircraft comprising: a heat engine; at least one nozzle having an exit facing a rear of the aircraft and adapted for conducting exhaust gas from the heat engine at least partially into ambient air flowing around the nozzle during operation of the aircraft to produce a gas mixture; at least one separator for separating condensed-out water from the gas mixture; and at least one of a collecting channel for separated water or a condensate pump for drawing off separated water.

7. The aircraft as recited in claim 6 wherein the at least one nozzle is adapted for discharging exhaust gas led therethrough on an outer surface of the aircraft over which at least a portion of the ambient air flows during operation of the aircraft, or into a mixing channel through which at least a portion of the ambient air flows during operation of the aircraft.

8. The aircraft as recited in claim 6 wherein the at least one separator includes a first pole for electrostatically charging water molecules in the exhaust gas and a second, complementary pole for attracting charged, condensed-out water.

9. An aircraft comprising: a heat engine; at least one nozzle having an exit facing a rear of the aircraft and adapted for conducting exhaust gas from the heat engine at least partially into ambient air flowing around the nozzle during operation of the aircraft to produce a gas mixture; at least one separator for separating condensed-out water from the gas mixture; wherein the at least one nozzle is adapted for discharging exhaust gas led therethrough on an outer surface of the aircraft over which at least a portion of the ambient air flows during operation of the aircraft, or into a mixing channel through which at least a portion of the ambient air flows during operation of the aircraft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred exemplary embodiments of the present invention will be described in greater detail below with reference to the drawing. It is understood that individual elements and components may be combined differently than described. Reference numerals for mutually corresponding elements are used for both figures and, as the case may be, are not respecified for each figure.

(2) In the schematic drawing:

(3) FIG. 1 shows a first exemplary specific embodiment of an aircraft according to the present invention; and

(4) FIG. 2 shows a second exemplary specific embodiment of an aircraft according to the present invention.

DETAILED DESCRIPTION

(5) FIG. 1 schematically shows a first exemplary embodiment of an aircraft 100 according to the present invention. The aircraft, which is suited, in particular for implementing a method according to the present invention, encompasses a heat engine 10 for propelling aircraft 100 as well as a conduit system 31 schematically illustrated in the figure that is adapted for conducting exhaust gas A from the heat engine to a nozzle 30.

(6) In the illustrated operation of the aircraft (in the region of a boundary layer), nozzle 30 is at least partially circumflowed by ambient air U and is adapted for discharging exhaust gas A led therethrough in the direction of flow of ambient air U on a surface 20 over which the ambient air flows (thus, along which the ambient air flows). Thus, exhaust gas A and the respective portion of ambient air U mix at surface 20. The resulting gas mixture then continues to flow along surface 20.

(7) The inventive mixing of exhaust gas A with ambient air U allows moisture contained in the exhaust gas to be efficiently cooled to below the dew point, without the aircraft having to be equipped therefor with heavy and bulky special devices, such as heat exchangers (which are effective in the current field of application). The cooling causes a greater drop in the saturated vapor pressure in the gas mixture than in the partial pressure of the water; supersaturation occurs, and fine water droplets W form on what are commonly known as condensation nuclei (for example, on dust particles and/or soot particles and/or on electrically charged molecules).

(8) Furthermore, aircraft 100 has a separator device 40, which, in the present case, includes a spray electrode 41 for charging the water molecules in accordance with the corona charging method (impact ionization) and a precipitation electrode 42, which extends along surface 20 as a result of an applied pole that is complementary to the spray electrode. The electrostatic forces cause water droplets W to move in the direction of the surface, where, further downstream, they contact surface 20 and then, for example, are passed into a collecting channel 50.

(9) Alternatively or additionally, the separator device of an aircraft according to the present invention could include a device for centrifugally separating and/or for centrifuging out at least a portion of the condensed-out water (not shown).

(10) In addition, the illustrated example of an aircraft 100 according to the present invention has a condensate pump 51 which is adapted for drawing off the thus separated water from collecting channel 50. The water may then be allowed to drain overboard directly via a discharge conduit 52, and/or at least a portion of the water may be fed to a water treatment 53 and, subsequently theretothrough a channel system 54 (schematically illustrated in the FIG.)to heat engine 10. There, the water may be directly injected into the combustion chamber of the heat engine, for example, or fed to a steam generator which uses the exhaust gas heat of the heat engine to generate steam.

(11) FIG. 2 schematically shows an aircraft 100 in accordance with an alternative specific embodiment of the present invention. In contrast to aircraft 100 shown in FIG. 1, nozzle 30 of aircraft 100 is located inside a mixing channel 60. The ambient air, which partially flows over the aircraft (namely upstream from the nozzle) (preferably from a boundary layer), flows through channel 60 and is thereby mixed with exhaust gas A.

(12) An inlet opening 61 of the mixing channel may be varied by a flap 62 (and preferably by an associated actuation and control unit that is not shown), so that an inflow of ambient air U into mixing channel 60 is variable, for example, as a function of a respective current output power of the heat engine and/or of a temperature of ambient air U.

(13) Similar to the example shown in FIG. 1, nozzle 30 of aircraft 100 also has a spray electrode 41 for electrostatically charging water molecules in the exhaust gas. In the present exemplary embodiment, an associated precipitation electrode 42 of aircraft 100 is formed as part of a channel wall of mixing channel 60, toward which water droplets W are directed in response to the electrostatic forces. Analogously to the case illustrated in FIG. 1, the thus separated water is collected and removed.

(14) A method is described for reducing contrails during operation of an aircraft 100, 100 having a heat engine 10. The method includes inducing a condensation of moisture contained in exhaust gas A of the heat engine by mixing at least a portion of the exhaust gas with ambient air U of the aircraft as well as separating the condensed-out water on the aircraft.

(15) Also described is an aircraft 100, 100 having a heat engine 10. The aircraft includes at least one nozzle 30 which is adapted for conducting exhaust gas A from the heat engine of the aircraft at least partially into ambient air U of the aircraft and thus to produce a gas mixture, and includes at least one separator device 40 for separating condensed-out water from the gas mixture.

LIST OF REFERENCE NUMERALS

(16) 10 heat engine 20 surface of the aircraft 30 nozzle 31 conduit system 40 separator device 41, 41 spray electrode 42, 42 precipitation electrode 50 collecting channel 51 condensate pump 52 discharge conduit 53 water treatment 54 channel system 60 mixing channel 61 variable inlet opening 62 adjustable flap 100, 100 aircraft A exhaust gas U ambient air W condensed-out water droplets