Double inlets exhaust system for unmanned aerial vehicle

Abstract

The dual inlet exhaust design for the flying device incorporates easy-to-assemble designs with low number of components, suitable for limited space and small volume requirements, good performance. The exhaust is designed as a three-chamber cylinder with two coaxial inlet pipes running through the two chambers on both sides, extending into the middle compartment. The width of the two inlet tubes in the middle compartment is different. The inlet pipe at the two compartments on both sides has a bore. The outlet tube is located in the middle compartment, deviating to the side with a smaller expansion inlet, with the longitudinal axis of the outlet tube passing through the inlet tube.

Claims

1. A two-inlet exhaust pipe for an aerial vehicle, comprising: an exhaust frame body having three chambers, two inputs, and an output of which: the exhaust frame body comprises a circular cylinder having two ends and a diameter, using aluminum alloy material, wherein the body is divided into the three chambers by a first and second partition separating the chambers, in which the two chambers at the two ends of the exhaust frame body are substantially the same configuration, with a total volume of the two end chambers of the exhaust frame body being smaller than a volume of the middle chamber; two hollow round cylinders positioned coaxially on each of the two ends of the exhaust frame body and having inlet ends in communication with an exterior of the exhaust frame body and outlet ends in communication with the middle chamber of the exhaust frame body, the diameters of the hollow round cylinders being less than ⅓ of the diameter of the exhaust frame body; the two hollow round cylinders extend through the two end chambers of the body of the exhaust frame and extend a first and a second distance into the middle chamber to position the two outlets within the middle chamber, in which an extension distance into the middle chamber of a first of the hollow round cylinders is from 1.2 to 1.8 times an extension distance of a second of the hollow round cylinders; an outlet of the exhaust frame body comprising a cylindrical-shaped device, located in the middle chamber oriented perpendicular to the exhaust shaft on both ends, positioned closer to the second outlet with a shorter extension distance into the middle cavity.

2. A two-inlet exhaust pipe for an aerial vehicle according to claim 1, in which at a wall surface of the hollow round cylinders inside the end chambers of the exhaust frame body are formed holes which are evenly distributed, forming a chamber resonate with porosity, the ratio of area in % of the formed holes portions to a total surface area of the hollow round cylinder portions inside the end chambers satisfies: $\sigma =0.03739{\left(\frac{L}{D}\right)}^{-8.075}+3.288$ where L, D are a length and a diameter of the chamber, respectively.

Description

BRIEF DESCRIPTION OF THE FIGURE

(1) FIG. 1: A drawing of a section along the exhaust shaft.

DETAILED DESCRIPTION

(2) Refer to FIG. 1, the exhaust of the two engine inlet for the flying device according to the proposed invention includes: the body of the exhaust frame with three chambers: the first compartment 1, the second compartment 2, the third compartment 3; two inputs; output 8. In which:

(3) The body of the exhaust frame is circular cylinder, using aluminum alloy material, capable of working in high temperature environments. The exhaust frame body is divided into the first compartment 1, the second compartment 2, the third compartment 3 and separated by the first compartment wall 4 and the second compartment wall 5. The first compartment and the third compartment are similarly designed. The total combined volume of the first chamber 1 and the third chamber 3 is smaller than the volume of the second chamber 2.

(4) The two inlets are two hollow round cylinders, hereinafter referred to as first cylinders 6 and second cylinders 7 and are coaxially located on both sides of the exhaust frame body, i.e. the two flat bottom surfaces of the exhaust frame. The diameter of this cylinder is smaller than ⅓ of the diameter of the bottom of the exhaust frame.

(5) The first cylinder 6 pierces the whole first chamber 1 and extends a distance into the second chamber 2, this interval is defined as x.

(6) The second shaft cylinder 7 passes through the third compartment 3 and extends a distance into the second compartment 2, where the length of the extension extends into the second compartment 2, which is defined as y.

(7) Design of two exhaust pipes in accordance with the present invention, is such that the segment y is 1.2 to 1.8 times larger than x. The extension of two cylindrical cylinders into the second chamber 2 forms an expanded resonant tube. The two extension segments have different lengths to create two different resonant frequencies, since the resonant frequency depends on the extension segment length.

(8) At the wall surface of the first 6-axis cylinder inside the first chamber 1 and the 7-part second cylinder inside the third chamber 3 are drilled evenly distributed openings, forming a resonant chamber. Porosity, the ratio of the area in % of the bore to the total surface area of the pipe inside the cavity, is calculated using the following formula:

(9) $\sigma =0.03739{\left(\frac{L}{D}\right)}^{-8.075}+3.288$

(10) Where L and D are the length and diameter of the cavity, respectively.

(11) Output 8 is a cylindrical-shaped device, located in the third chamber 3 perpendicular to the shaft of the two inlet exhaust pipes, deviating towards the first chamber 1 with the long axis of the shaft passing through the first cylinder 6. This helps the air flow into the second chamber from the first axis 6 cylinder have a greater degree of direction change than if output 8 were placed in the middle of the third chamber. It also helps to extend the path of air flow from the second axis 7 and increase the area being changed. The cross-sectional area of output 8 is smaller than the total cross-sectional area of the first cylinder 6 and the second cylinder 7, which makes the air velocity at the output to be larger than the input, increasing the efficiency and decreasing noise.

(12) The design of the two-input exhaust pipe according to the proposed invention has the following working principle: the exhaust pipe uses destructive interference to minimize noise, which means that sound waves generated from the engine when passing through the exhaust pipe will automatically interfere with reflected waves and then suppressing each other. Reflection occurs when there is a change in geometry, area or when there is a change in air flow direction.