Device for mixing fresh air and heating air and use of the device in a ventilation system of an aircraft

1. A device for mixing fresh air and heating air in a ventilation system installed on board an aircraft, the device comprising:

a fresh air source and a source of heating air;

a fresh air inlet fluidly connected with the fresh air source to supply the fresh air,

a heating air supply body supplying the heating air from the source of heating air, and

a mixed air outlet for delivering mixed fresh air and heating air from the device,

wherein the heating air supply body includes a first portion and a second portion which constitute a flow resistance to the fresh air,

wherein the second portion is formed as a closed hollow body with a plurality of heating air supply openings and is connected to the first portion at a downstream end of the first portion, viewed in the flow direction of the heating air, wherein the number of heating air supply openings in a downstream area of the second portion is greater than in an upstream area of the second portion, and a surface density of the heating air supply openings at the second portion increases in the flow direction of the fresh air, and

wherein the first portion is formed as a supply line extending into the device to the second portion, the supply line defining, as seen in the flow direction of the fresh air, a streamlined shape in the form of a teardrop cross-section.

2. The device according to claim 1 , wherein the second portion defines a streamlined shape viewed in the flow direction of the fresh air.

3. The device according to claim 1 , wherein the second portion is of spherical or elliptical shape.

4. The device according to claim 2 , wherein the cross-sectional area of the first portion in the flow direction of the fresh air is smaller than the cross-sectional area of the second portion.

5. The device according to claim 2 , wherein the plurality of heating air supply openings at the second portion are uniformly distributed.

6. The device according to claim 2 , wherein the number of heating air supply openings in a downstream area of the second portion is greater than in an upstream area of the second portion.

7. The device according to claim 2 , wherein the second portion defines a teardrop shape defined along a flow direction of the fresh air.

8. The device according to claim 2 , wherein a flow direction of the heating air in the first portion of the heating air supply body is perpendicular to the flow direction of the fresh air.

9. The device according to claim 1 , further comprising:

a first body including the fresh air inlet and the mixed air outlet, wherein the heating air supply body is fastened to the first body.

10. The device according to claim 9 , wherein the first body is made of a glass-fibre reinforced plastics material and the heating air supply body is made of a titanium alloy.

11. The device according to claim 9 , wherein a temperature sensor is disposed on the first body downstream of the heating air supply body.

12. A method for mixing fresh air and heating air in a ventilation system installed on board an aircraft, the method comprising:

installing a device in the ventilation system, the device comprising a fresh air inlet fluidly connected to a source of fresh air, a heating air supply body supplying the heating air from a source of heating air, and a mixed air outlet for delivering mixed fresh air and heating air from the device, wherein the heating air supply body includes a first portion and a second portion which constitute a flow resistance to the fresh air, wherein the second portion is formed as a closed hollow body with a plurality of heating air supply openings and is connected to the first portion at a downstream end of the first portion, viewed in the flow direction of the heating air, wherein the number of heating air supply openings in a downstream area of the second portion is greater than in an upstream area of the second portion, wherein a surface density of the heating air supply openings at the second portion increases in the flow direction of the fresh air, and wherein the first portion is formed as a supply line extending into the device to the second portion, the supply line defining, as seen in the flow direction of the fresh air, a streamlined shape in the form of a tear drop cross-section;

delivering fresh air through the fresh air inlet into the device; and

delivering heating air through the heating air supply body into the device for mixing with the fresh air and discharge at the mixed air outlet.