Patent ID: 12241381

DETAILED DESCRIPTION OF THE INVENTION

A gas mixing device10and a moving object12according to an embodiment of the present invention will be described below with reference to the drawings. As shown inFIG.1, the gas mixing device10according to the present embodiment is mounted on, for example, an aircraft14, which is the moving object12. The aircraft14is, for example, an electric vertical take-off and landing aircraft (eVTOL). The moving object12may be, for example, a ship, a vehicle, etc.

The aircraft14includes a fuselage16, a front wing15, a rear wing17, eight VTOL rotors18, and two cruise rotors20. The fuselage16extends in the front-rear direction of the aircraft14. The front wing15is provided at a portion further forward than the center of the fuselage16in the front-rear direction. The rear wing17is provided at a portion further rearward than the center of the fuselage16in the front-rear direction. The VTOL rotors18generate an upward thrust force for the aircraft14. The cruise rotors20generate a horizontal thrust force for the aircraft14. The two cruise rotors20are attached to the rear wing17, and the number and arrangement of each of the VTOL rotors18and the cruise rotors20can be set suitably.

Inside the fuselage16, a power generation module22is arranged. As shown inFIG.2, the power generation module22includes a gas turbine engine24, a generator26, and a gas mixing device10. The gas turbine engine24generates high-temperature combustion gas by burning fuel. The combustion gas causes the turbine30of the gas turbine engine24to rotate. The generator26is coupled to the turbine30. The generator26generates electric power by the turbine30rotating. The power generated by the generator26is supplied to electrical equipment. The electrical equipment may include, for example, electric motors for driving the VTOL rotors18and the cruise rotors20. Also, as the electrical equipment, batteries, inverters, and the like can be mentioned. The generator26is arranged in the X1direction with respect to the gas turbine engine24. It should be noted that the X1direction and the X2direction, which will be described later, are shown inFIG.2with arrows.

The gas turbine engine24discharges high-temperature exhaust gas in the X2direction as a result of the rotation of the turbine30. The X2direction is the opposite direction to the X1direction. The exhaust gas flows in a spiral shape around the axis Ax of the turbine30. In other words, the exhaust gas contains a swirling component with a negative pressure at the center of the swirling component. The swirling direction of the swirling component of the exhaust gas is, for example, clockwise when viewed from the X1direction.

The gas mixing device10is coupled to the gas turbine engine24. The gas mixing device10is positioned in the X2direction with respect to the gas turbine engine24. The gas mixing device10includes a discharge flow path32that discharges exhaust gas from the gas turbine engine24. The gas mixing device10cools the exhaust gas by mixing the exhaust gas flowing through the discharge flow path32with the cooling gas flowing through a radiator40, which will be described later. The cooled exhaust gas is discharged to the outside of the fuselage16.

The discharge flow path32is provided with a discharge pipe34, a cooling gas introducing portion36, and a diffuser38. The discharge pipe34extends from the gas turbine engine24in the X2direction.

The cooling gas introducing portion36is located downstream of the discharge pipe34. The cooling gas introducing portion36is provided with the radiator40. A cooling pipe44through which a cooling medium for cooling the generator26flows is connected to the radiator40. Outside air can circulate in the radiator40. The radiator40exchanges heat between the outside air and the cooling medium guided from the cooling pipe44. In other words, the radiator40cools the cooling medium with the outside air.

The outside air that has circulated through the radiator40is warmed by the cooling medium. However, the temperature of the outside air that has circulated through the radiator40is lower than the temperature of the exhaust gas. That is, the outside air that has circulated through the radiator40can be a cooling gas for cooling the exhaust gas. The outside air that has circulated through the radiator40is hereinafter referred to as cooling gas. As described above, the exhaust gas contains a swirling component with a negative pressure at the center of the swirling component. Thus, a portion with the negative pressure is generated in the discharge flow path32. Since the negative pressure is generated in the discharge flow path32, the cooling gas is drawn into the discharge flow path32via the cooling gas introducing portion36.

The cooling gas introducing portion36has an introducing main body46and a housing portion48. The introducing main body46is arranged on the downstream side (X2direction) of the discharge pipe34. The introducing main body46is made of, for example, a metal material. The introducing main body46includes a tubular portion50and a plurality (e.g., six) of guide portions52(seeFIGS.3-5). A communication passage54is provided inside the discharge pipe34to allow the inside of the tubular portion50and the gas turbine engine24to communicate with each other. The axis of the tubular portion50and the axis of the discharge pipe34coincide with an extension L of the axis Ax of the turbine30.

The housing portion48houses the introducing main body46. The housing portion48is connected to an extended end portion of the discharge pipe34. The radiator40is connected to the housing portion48. An introducing chamber56is provided between the outer peripheral surface of the tubular portion50and the housing portion48, and the cooling gas that has circulated through the radiator40is guided to the introducing chamber56. The tubular portion50is attached to the housing portion48.

As shown inFIGS.2to4, the tubular portion50is diametrically enlarged toward the downstream side of the discharge flow path32. In other words, each of the inner diameter and the outer diameter of the tubular portion50gradually increases in the X2direction. As shown inFIGS.2to5, the guide portion52guides the cooling gas guided to the introducing chamber56to a radially central portion58of the tubular portion50. The guide portion52is provided at the end portion of the tubular portion50on the downstream side (X2direction) of the discharge flow path32.

Since the pressure is negative at the center of the exhaust gas discharged from the gas turbine engine24to the communication passage54, the cooling gas guided to the central portion58of the tubular portion50flows toward the upstream side of the communication passage54. That is, the cooling gas guided to the central portion58of the tubular portion50is drawn to the upstream side of the discharge flow path32. In the communication passage54, the exhaust gas and the cooling gas are mixed. The exhaust gas mixed with the cooling gas flows along the outer peripheral side of the inside of the tubular portion50toward the downstream side of the discharge flow path32.

As shown inFIGS.3to5, the guide portions52are spaced apart in the circumferential direction of the tubular portion50. In other words, the guide portions52are arranged at equal intervals in the circumferential direction of the tubular portion50. The number of guide portions52can be set suitably. Between the adjacent guide portions52, an extracting flow path60is formed for letting the mixed gas flow in the X2direction.

The guide portion52extends radially inward from the tubular portion50. The central portion58of the interior of the tubular portion50, which is surrounded by the extended end portions of the guide portions52, is in communication with the communication passage54that is upstream of the tubular portion50(seeFIG.2).

The guide portion52has a first side wall portion62, a second side wall portion64, and a connecting portion66. Each of the first side wall portion62and the second side wall portion64extends radially inward from the tubular portion50. The first side wall portion62and the second side wall portion64are arranged to face each other in the circumferential direction of the tubular portion50.

When the introducing main body46is viewed from the X1direction, the first side wall portion62is located in the clockwise direction with respect to the second side wall portion64(seeFIG.4). The connecting portion66connects the X1-direction end portion of the first side wall portion62and the X1-direction end portion of the second side wall portion64to each other. Inward in the radial direction of the tubular portion50(seeFIG.2), the connecting portion66is inclined in the X2direction.

An introducing flow path68is provided between the first side wall portion62and the second side wall portion64to direct the cooling gas to the central portion58of the tubular portion50. The introducing flow path68is opened toward the downstream side of the discharge flow path32. As shown inFIG.5, the opening width W of the introducing flow path68in the X2direction is narrowed inward in the radial direction of the tubular portion50. The opening width W of the introducing flow path68is the interval between the X2-direction end of the first side wall portion62and the X2-direction end of the second side wall portion64along the circumferential direction of the tubular portion50.

The outer end68aof the introducing flow path68is located on the outer peripheral surface of the tubular portion50. The outer end68aof the introducing flow path68is in communication with an introducing space. The inner end68bof the introducing flow path68is located at the central portion58of the tubular portion50. The inner end68bof the introducing flow path68faces the radial center of the tubular portion50. The inner ends68bof the two introducing flow paths68located so as to sandwich the central portion58of the tubular portion50face each other. The inner end68bof the introducing flow path68is in communication with the central portion58of the tubular portion50. The size of the inner end68bof the introducing flow path68is smaller than the size of the outer end68aof the introducing flow path68.

The guide portion52functions as a guide vane (wing) for removing the swirling component of the exhaust gas. That is, the guide portion52changes the swirling component of the exhaust gas into a straight component along the X2direction.

As shown inFIG.4, the guide portion52is twisted counterclockwise toward the radially inward direction of the tubular portion50. The connecting portion66forms the leading edge of the wing. The outer surface of the first side wall portion62facing away from the introducing flow path68forms a suction surface of the wing. The outer surface of the second side wall portion64facing away from the introducing flow path68forms a pressure surface (pressure application surface) of the wing.

As shown inFIG.2, the diffuser38is located downstream of the introducing main body46. The diffuser38diffuses the exhaust gas guided from the extracting flow path60of the introducing main body46and discharges it to the outside of the fuselage16. The upstream end face of the diffuser38is in contact with or close to the downstream end face of the tubular portion50. Part of the diffuser38is inserted into the interior of the housing portion48. The inner diameter of the diffuser38increases toward the downstream side. In other words, the flow path cross-sectional area of the diffuser38increases toward the downstream side.

Next, the flow of the exhaust gas and the cooling gas in the gas mixing device10will be described. As shown inFIG.6, the gas turbine engine24discharges high-temperature exhaust gas into the communication passage54. In the communication passage54, the exhaust gas has a swirling component with the negative pressure at the center. Then, the outside air is guided to the radiator40by the suction force generated in the discharge flow path32. In the radiator40, heat exchange is performed between the outside air and the cooling medium flowing through the cooling pipe44. The temperature of the outside air warmed by heat exchange is well below the temperature of the exhaust gas discharged from the gas turbine engine24to the communication passage54. Therefore, the outside air becomes a cooling gas for the exhaust gas.

The cooling gas is guided to the introducing chamber56of the housing portion48by suction force. The cooling gas guided to the introducing chamber56flows to the central portion58of the tubular portion50via the introducing flow paths68of the guide portions52. The cooling gas flowing to the central portion58of the tubular portion50is guided to the communication passage54toward the upstream side of the discharge flow path32. In the communication passage54, the exhaust gas and the cooling gas are well mixed by the swirling component of the exhaust gas. Thereby, the temperature of the exhaust gas is reduced by the cooling gas. Thereafter, the exhaust gas mixed with the cooling gas flows on the outer peripheral side of the inside of the tubular portion50toward the downstream side of the discharge flow path32while swirling.

The exhaust gas flowing on the outer peripheral side of the inside of the tubular portion50touches the guide portions52. Thus, the swirling component of the exhaust gas is changed to the straight component along the downstream direction of the discharge flow path32. The exhaust gas from which the swirling component is removed is discharged to the outside from the extracting flow path60via the diffuser38. In this case, the exhaust gas flows along the wall surface of the diffuser38. Thus, the exhaust of the gas turbine engine24can be smoothly discharged, and thus the gas turbine engine24can be efficiently driven.

In the present embodiment, the flow of the cooling gas from the introducing chamber56to the discharge flow path32varies depending on the flow rate of the exhaust gas, the length of the communication passage54, the flow path cross-sectional area of the communication passage54, and the like. Therefore, in the present embodiment, there is a case where the cooling gas flows as shown inFIG.7. In this case, as shown inFIG.7, part of the cooling gas that has flowed into the introducing flow path68from the introducing chamber56flows into the diffuser38toward the downstream side of the discharge flow path32before reaching the central portion58of the tubular portion50. On the other hand, the cooling gas guided from the introducing chamber56to the central portion58of the tubular portion50via the introducing flow path68of the guide portion52flows into the tubular portion50toward the upstream side of the discharge flow path32. Inside the tubular portion50, the exhaust gas and the cooling gas are well mixed by the swirling component of the exhaust gas. In the example ofFIG.7, the cooling gas does not flow to the communication passage54. The swirling component of the exhaust gas mixed with the cooling gas is changed into the straight component by the plurality of guide portions52. The exhaust gas from which the swirling component has been removed is guided to the diffuser38.

According to the present embodiment, the exhaust gas is discharged from the gas turbine engine24to the communication passage54. The exhaust gas contains the swirling component with the negative pressure at the center of the swirling component. Therefore, the cooling gas is drawn from the guide portion52to the communication passage54via the radially central portion58of the tubular portion50. Thus, the cooling gas and the exhaust gas can be well mixed by the swirling component of the exhaust gas in the communication passage54or the tubular portion50. The exhaust gas mixed with the cooling gas is discharged to the downstream side of the discharge flow path32through the outer peripheral side of the inside of the tubular portion50(the outside of the central portion58).

The present embodiment is not limited to the above-described configuration. The introducing flow path68provided at the guide portion52may be closed, not opening toward the downstream side of the discharge flow path32.

With respect to the above disclosure, we further disclose the following Supplemental Notes.

Supplemental Note 1

A gas mixing device (10) includes a discharge flow path (32) that discharges exhaust gas from a gas turbine engine (24), and the gas mixing device mixing the exhaust gas flowing through the discharge flow path with a cooling gas flowing through a radiator (40), wherein the discharge flow path includes a tubular portion (50), a communication passage (54) that allows an inside of the tubular portion and the gas turbine engine to communicate with each other, and a plurality of guide portions (52) that extend radially inward from the tubular portion and guide the cooling gas to a radially central portion (58) of the tubular portion, the plurality of guide portions are spaced from each other in a circumferential direction of the tubular portion, and the extended end portions of the plurality of guide portions are spaced from each other.

According to such a configuration, the exhaust gas containing the swirling component that has the negative pressure at the center is discharged from the gas turbine engine into the communication passage. Therefore, the cooling gas is drawn from the guide portion to the communication passage via the radially central portion of the tubular portion. Thus, the cooling gas and the exhaust gas can be well mixed by the swirling component of the exhaust gas inside the tubular portion or the communication passage. The exhaust gas mixed with the cooling gas is discharged to the downstream side of the discharge flow path through the outer peripheral side of the inside of the tubular portion.

Supplemental Note 2

In the gas mixing device according to Supplemental Note 1, the gas turbine engine may discharge the exhaust gas containing a swirling component with a negative pressure at the center of the swirling component.

Supplemental Note 3

In the gas mixing device according to Supplemental Note 1 or 2, the central portion of the inside of the tubular portion that is surrounded by the extended end portions of the plurality of guide portions may be in communicate with the communication passage located upstream of the tubular portion in the discharge flow path.

Supplemental Note 4

In the gas mixing device according to Supplemental Note 2, a diffuser (38) may be provided in the discharge flow path on the downstream side of the tubular portion, and the plurality of guide portions may remove the swirling component of the exhaust gas and let the exhaust gas flow to the diffuser.

According to such a configuration, the swirling component of the exhaust gas can be removed by the guide portion and thus the exhaust gas can flow smoothly into the diffuser.

Supplemental Note 5

In the gas mixing device according to Supplemental Note 4, the guide portion may be twisted around a radially inward direction of the tubular portion.

According to such a configuration, the swirling component of the exhaust gas can be satisfactorily removed by the guide portion.

Supplemental Note 6

In the gas mixing device according to any one of Supplemental Note 1 to 5, each of the plurality of guide portions may include a pair of side wall portions (62,64) that extend radially inward from the tubular portion and are arranged to face each other in the circumferential direction of the tubular portion, and a connecting portion (66) that connects end portions of the pair of side wall portions on an upstream side of the discharge flow path, and wherein an introducing flow path (68) may be provided between the pair of side wall portions to guide the cooling gas to the central portion of the tubular portion.

According to such a configuration, the guide portion can be made into a simple configuration. In addition, the cooling gas can be introduced into the central portion of the tubular portion via the introducing flow path of the guide portion.

Supplemental Note 7

In the gas mixing device according to Supplemental Note 6, the introducing flow path may open toward the downstream side of the discharge flow path.

According to such a configuration, the guide portion can be made into an even simpler configuration.

Supplemental Note 8

In the gas mixing device according to any one of Supplemental Notes 1 to 7, the guide portion may be provided at the end portion of the tubular portion on the downstream side of the discharge flow path.

According to such a configuration, the guide portion can be easily provided in the tubular portion.

Supplemental Note 9

The gas mixing device according to Supplemental Note 6 may further include a housing portion (48) that houses the tubular portion, wherein an introducing chamber (56) into which the cooling gas is introduced is provided between the outer peripheral surface of the tubular portion and the housing portion, and the introducing flow path includes an outer end (68a) that is located on the outer peripheral surface of the tubular portion and an inner end (68b) that is located on an inner side of the tubular portion.

According to such a configuration, the cooling gas introduced into the introducing chamber can be guided to the central portion of the tubular portion via the introducing flow path.

Supplemental Note 10

In the gas mixing device according to Appendix 9, the size of the inner end of the introducing flow path may be smaller than the size of the outer end of the introducing flow path.

According to such a configuration, the cooling gas can be smoothly drawn into the communication passage via the introducing flow path.

Supplemental Note 11

In the gas mixing device according to any one of Supplemental Notes 1 to 10, the inner diameter of the tubular portion may be enlarged toward the downstream side of the discharge flow path.

According to such a configuration, the mixed gas flowing through the tubular portion can flow well to the downstream side of the discharge flow path.

Supplemental Note 12

The moving object (12) includes the gas mixing device according to any one of Supplemental Notes 1 to 11.

The present invention is not limited to the above-described disclosure, and various configurations can be adopted without departing from the scope of the present invention.