Outer cylinder of a propulsion system for flying cars, etc.

Abstract

To solve problems when a flying car of a size in such a degree of a compact car performs high speed flight in which (1) a current propulsion machine is made compact, (2) air resistance is reduced because of high speed flight, (3) a high-speed flow flowing in a radiator is decelerated, and both of a pressure loss due to air resistance in the radiator and cooling performance are optimized, and (4) a take-off / landing site is restricted in a city and the like, and therefore a short take-off / landing performance is needed.SOLUTION: A propulsion machine 2 is stored in an outer cylinder 1 having ejector principle in order to improve propulsive force of a flying car. Also, the outer cylinder 1 and its attached equipment are made into an aerodynamically-refined configuration and structure / mechanism. Also, an added value such as a radiator being built in the outer cylinder 1 or a boundary-layer control of a main wing flap are acquired.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] It relates to flying vehicles (amphibious vehicles), airplanes, and more specifically, drone-type flying vehicles (vertical takeoff and landing).

Background Art

[0002] The outer cylinder 1 of the present invention uses the principle of an ejector. The ejector uses a high-speed jet (air, water, steam) as the driving source. Due to its negative pressure, it accelerates, sucks, and mixes the surrounding fluid, and decelerates in the diffuser section 5 (expanding flow path) to recover the dynamic pressure. Since it has no moving parts like pumps or fans and has a simple structure, it is used for sewage with harsh usage conditions (poor water quality, corrosive environment, solid-liquid two-phase with many impurities), corrosive gases, discharge and transportation of high-temperature steam, etc. It is also used in various applications such as aeration, vacuum pumps, and recently, ejector refrigeration cycles. In automobiles, a radiator is used for engine cooling. Since it is installed at the front of the vehicle body, this part is not streamlined but has a bluff shape, resulting in a large air resistance coefficient Cd. Also, air flowing at the same speed as the vehicle speed flows into the radiator. These factors are major causes of increased air resistance in flying vehicles that fly at high speeds (about 200 km / h to 700 km / h).

Prior Art Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] For the following reasons, it is considered that flying vehicles will not only be of the drone type but also long-distance / high-speed flight types that travel between cities and regions at high speeds of about 200 km / h to 700 km / h with a flight range of 300 km to 800 km will be put into practical use. (1) Major technological innovations, primarily in the automotive sector. ▲1▼Significant improvement in driving safety Automotive fail-safe capabilities (such as avoiding collisions with objects and preventing driver errors) have rapidly improved thanks to sensors (laser, infrared, ultrasonic sonar, Doppler radar, etc.) and data processing technology, making them sufficiently safe even in the air and at sea. ▲2▼Permanent magnet synchronous motors and their high-performance, high-speed inverters for control (which have excellent characteristics in terms of loss, frequency, capacity, etc. due to the use of SiC elements), as well as hydrogen fuel engines, are examples of the diversification and performance advancements (high efficiency, high output, high speed and miniaturization, energy saving, etc.) of prime movers and propulsion systems that are currently undergoing technological innovation. (2) The major advantages of flying cars ▲1▼Reduction of fuel costs Flying cars can fly the shortest distance (straight line) between two points. For example, the distance between Osaka and Tokyo on the Shinkansen is 515 km, which is more than 25% longer than the straight-line distance of 400 km. ▲2▼Flying car air routes are 3D While automobiles are limited to two dimensions (the ground) and only travel on specific roads, air travel is three-dimensional. Moreover, destinations, speeds, and purposes (private use / bus transport / transportation) can be assigned to each altitude. ▲3▼Significant reduction in transportation infrastructure development costs Both expressways and bullet trains require enormous initial and maintenance costs. Furthermore, many expressways are reaching the end of their lifespan and need for renovation. ▲4▼Creation of new transportation systems and new lifestyles This technology is effective for transporting passengers over distances of several hundred kilometers, similar to express buses with a capacity of 50 to 100 people, or minibuses with a capacity of around 20 people. Express buses have a daily limit of 9 hours of driving time and are required to have a relief driver on board, which reduces the profitability of chartered sightseeing buses (especially overnight tours). On the other hand, the straight-line distance from Cape Sata at the southern tip of Kyushu to Cape Soya at the northern tip of Hokkaido is 1888 km, so a flying car traveling at 500 km / h could cover that distance in just under 4 hours. In other words, with a flying car, chartered sightseeing tours to various parts of Japan could be completed in a maximum of 4 hours. It would also be possible to travel from Osaka or Tokyo to anywhere in the country in about 2 hours. As a result, groups of several dozen tourists from both Japan and abroad would be able to easily travel to various parts of the country (including remote mountain areas), and tourism revenue would increase significantly. Furthermore, there would be no influence from terrain such as the sea, rivers, or mountains, and there would be no road congestion or detours, so fatigue for drivers and tourists would be reduced. Flying cars, as "private flying vehicles," combine the convenience of cars for short distances and airplanes for long distances. For example, they could travel by ground from a residential home or a city office garage to nearby destinations, and then take off and land at high speed from multi-lane national highways, expressways, or even short straight roads of a few hundred meters along riverbanks to reach distant destinations. Furthermore, the one-hour commute radius of a major city could be extended to a radius of several hundred kilometers, allowing people to own homes in pleasant mountainous areas, rural areas, or by the sea. This will improve the attractiveness, commercial power, and industrial creation capabilities of influential regional cities (such as prefectural capitals), as well as the convenience of surrounding areas, leading to regional revitalization. It will also improve convenience and integration in areas with maritime constraints, such as the Setouchi region and island areas.

[0005] On the other hand, for a "flying private car" the size of a compact car or sedan to fly at high speeds of 200 to 700 km / h faces the following challenges: ▲1▼The current propulsion system is too large (even the Cessna 152's propeller diameter is 1750mm), so it needs to be made more compact. ▲2▼Since it flies at high speed, part or all of the outer casing or its accessories are made into an aerodynamically refined shape such as an airfoil to suppress the large air resistance generated in high-speed airflow. ▲3▼ Because it flies at high speeds, the engine output is greater than that of a car, and the radiator capacity is increased. In addition, the incoming high-speed airflow (167 m / s at 600 km / h) is slowed down, and the radiator optimizes the trade-off between pressure loss due to air resistance and cooling performance. ▲4▼Since takeoff and landing sites are restricted in urban areas, etc., short takeoff and landing capabilities are necessary. [Means for solving the problem]

[0006] To improve the thrust of the flying car, the thruster 2 is housed in an outer cylinder 1 that utilizes the ejector principle. Furthermore, the outer cylinder 1 and its associated equipment are given an aerodynamically refined form, structure, and mechanism. In addition, value-added features such as a built-in radiator and boundary layer control for the main wing flaps are added to the outer cylinder 1. [Effects of the Invention]

[0007] The ejector effect of the outer cylinder 1 increases thrust. Furthermore, it provides a solution to the challenges of high-speed flight described above (2 and 3). [Brief explanation of the drawing]

[0008] [Figure 1] This is a conceptual diagram (cross-sectional view) of the basic form for carrying out the invention. [Figure 2] This is a conceptual diagram (cross-sectional view) of an example in which a radiator is built into an airfoil-shaped lateral partition plate. [Figure 3] This is a conceptual diagram (cross-sectional view) of an example where the radiator is built into the outer casing. [Figure 4] This is Example 1. [Figure 5] This is a conceptual diagram (cross-sectional view) of the outer cylinder, showing the front and rear sections being separated and the rear section being movable. [Figure 6] This is Example 2. Modes and Examples for Carrying Out the Invention Basic Mode for Carrying Out the Invention

[0009] Figure 1 shows the basic form (cross-sectional view) of the outer cylinder 1 for carrying out the invention. Its ejector effect is as follows. ▲1▼A portion of the air (velocity C1) flowing into the outer cylinder 1 enters the prime mover 4, is accelerated to velocity C2, and generates thrust. ▲2▼The remaining air (velocity C1) that has flowed into the outer cylinder 1 is also drawn in and accelerated by the high-speed flow C2 at the outlet of the above-mentioned motorized thruster 4, generating thrust. Furthermore, while the two mix, they are decelerated to an outflow velocity C3 in the enlarged flow path of the diffuser section 5, and the thrust is further increased by the recovery of the dynamic pressure. Embodiment 1 for carrying out the invention of claim 2

[0010] The radiator 6 is a crucial component for cooling the prime mover, permanent magnet synchronous motor, and its high-voltage components and power semiconductor equipment (inverters, DC-DC junction boxes, chargers, etc.). However, it is necessary to slow down the high-speed airflow (167 m / s at 600 km / h) entering the radiator during high-speed flight, and optimize the trade-off between pressure loss due to air resistance within the radiator 6 and cooling performance (diffusion radiator). For this reason, in reciprocating engine aircraft, the airflow path from the air intake to the radiator is sometimes made into a diffuser to slow down the high-speed airflow, but countermeasures against the development and separation of the inflow boundary layer due to deceleration are extremely important.

[0011] Therefore, as an example of means and form for carrying out the invention of claim 2, a radiator 6 is built into an airfoil-shaped transverse partition plate 7, as shown in the conceptual diagram of Figure 2. Since this plate 7 is thick, it is made into an airfoil shape or the like to reduce air resistance, thereby suppressing the large air resistance generated in the high-speed flow. Furthermore, if the parts of this plate 7 facing the radiator inlet and outlet (the parts indicated by the dashed lines in Figure 2) are made into openings, perforated plates (such as perforated metal), or plates with slits, the following effects can be obtained. Note that the orientation of the small holes in this perforated plate is perpendicular to the plate, but on the negative pressure side, they may be oriented in the direction downstream of the high-speed flow 15. ▲1▼A portion of the high-speed flow that flows along the pressure surface of the airfoil-shaped transverse partition plate 7 flows into the radiator 6 at a low speed (radiator cooling flow 16) and is drawn out to the negative pressure side where the pressure is lower. Therefore, the high-speed flow 15 does not flow directly into the radiator 6, and deceleration by the diffuser becomes unnecessary. ▲2▼The frontal projected area of ​​radiator 6 is small, resulting in low air resistance. Increasing the capacity and size of the radiator 6 for increasing the output of the prime mover 3 is easy in terms of structure, strength, and fluid performance (air resistance). Mode 2 for implementing the invention of claim 2

[0012] As another means and example of the form for implementing claim 2, Fig. 3 shows a conceptual diagram (cross-sectional view) in which a radiator 6 is incorporated in an outer cylinder 1 configured in an axisymmetric shape such as a cylinder or a cone. The inside of the outer cylinder 1 is made hollow, and a cylindrical radiator 6 that sucks in a cooling flow from the inner peripheral surface and discharges it from the outer peripheral surface is incorporated. If the two-dot chain line portion ▲1▼ on the inner peripheral surface of the outer cylinder 1 facing the inlet of the radiator 6 is made an opening, a perforated plate, or a plate with slits, the radiator cooling flow 16 flows in and is sucked out to the two-dot chain line portion ▲2▼ on the outer peripheral surface of the outer cylinder 1 (an opening, a perforated plate, or a plate with slits similar to the two-dot chain line portion ▲1▼). Since a large negative pressure is generated if the two-dot chain line portion ▲2▼ has a shape similar to the front part of the negative pressure surface of an airfoil, this sucking effect is enhanced.

[0013] Also, the flow path ▲3▼ formed by the outlet portion of the radiator 6 and the upper surface of the outer cylinder 1 is a confluence portion of the outflow air from the radiator 6. Since the cross-sectional area of this main flow path expands toward the suction / discharge port (two-dot chain line portion ▲2▼), this confluent flow becomes almost equi-velocity. For this reason, the flow velocity distribution in the radiator 6 can be made almost constant, its cooling efficiency is high, and the pressure loss is small.

[0014] In addition, this example also has the following effects and advantages. ▲1▼ Since the inlet portion of the outer cylinder 1 is streamline, the air resistance is small. ▲2▼ When the flying vehicle is ascending or the like, the angle of attack at the upper part of the outer cylinder 1 becomes large and there is a possibility of separation. However, the outflow air from the two-dot chain line portion ▲2▼ supplies momentum to the flow and suppresses separation, similar to a leading-edge slat. ▲3▼ Since there are cavities throughout the circumference of the outer cylinder, soundproofing materials can be inserted to reduce noise.

Example 1

[0015] Example 1 is shown in Fig. 4. Along with the improvement of the propulsion force due to the ejector effect of the outer cylinder 1, this example has the following effects. ▲1▼ The inclined section 13 at the rear of the upper surface of the vehicle body has a flow path shape equivalent to a curved diffuser, so large-scale separation and backflow are likely to occur. However, in this embodiment, it is part of the outer cylinder 1, so it becomes an internal flow and these are suppressed by the wall effect of the opposing wall. However, since the diffuser expansion angle tends to be large in this inclined section 13, if necessary, a lateral partition plate (bent thin plate) 17 can be attached to suppress the occurrence of separation and backflow. ▲2▼The partition plate is a horizontal partition plate (airfoil) 18, and the Coanda effect of the wall jet flowing along its negative pressure surface generates a large lift, which assists the main wing 10. The mounting angle of the plate is variable, and the angle is increased when a large lift is required, such as during takeoff and landing. As shown in the conceptual diagram of Figure 5, the same effect can be obtained by dividing the outer cylinder 1 into a front and rear section, and making the rear section movable to deflect the flow downwards. ▲3▼Since the flow inside the diffuser is decelerated, separation is likely to occur if the expansion angle is large, but in the diffuser section 5 of this outer cylinder, the flow is pressed against the inner wall by the centrifugal force from the swirling flow from the propeller outlet, so separation is unlikely to occur. However, spiral grooves or the like may be added to the inner surface of the outer cylinder 1 to give the flow a swirling motion, further suppressing separation and increasing the magnification angle. Conversely, in order to recover the swirling flow of the propeller as dynamic pressure, the diffuser section 5 may be made into guide vanes (stator vanes) similar to those of a fan or pump. ▲4▼The thruster 2 in this example is a ducted propeller housed in a casing, and has the following advantages over conventional propellers. • The gap between the outer end of the propeller and the casing can be reduced (to about 0.3% of the propeller diameter), significantly reducing leakage flow loss due to tip vortices from the pressure surface to the negative pressure surface at the outer end. • The total pressure distribution can be designed to be constant in the radial direction (free vortex type), which increases output and efficiency. By narrowing the rear of the casing into a cone shape and reducing the cross-sectional area of ​​the flow path, the high-speed flow from the propeller becomes even larger, increasing the ejector effect.

[0016] This embodiment also has the following functions, forms, and structures. ▲1▼ The thruster 2 (ducted propeller) is separated from the vehicle body 12 and does not draw in the low-energy, velocity-deficient boundary layer that develops on the upper surface of the vehicle body 12. ▲2▼To ensure high lift during takeoff and landing, the downward angle of the flaps 11 on the main wing 10 shall be set to a maximum of approximately 45°. On the other hand, to generate downforce during ground taxiing, the upward angle of the flaps 11 shall be set to a maximum of approximately 30°. The flaps 11 are located near the drive rear wheels, and the downforce effectively contributes to their grip. ▲3▼A portion of the vertical stabilizer 14 (forward of the root) constitutes a portion of the outer cylinder of claim 1, and has a rectifying effect as a partition plate. ▲4▼Since the rudder 19 of the vertical stabilizer 14 is close to the thruster 2, the Coanda effect of its high-speed jet improves the effectiveness of the rudder. ▲5▼The reason for using wheels for ground travel instead of a propulsion system is to minimize noise in urban areas and residential neighborhoods. ▲6▼When traveling on the ground, the prime mover 3 (motor) mounted behind the propeller drives the rear wheels via a gear mechanism. ▲7▼If the prime mover 3 is large, it is mounted at the rear of the vehicle and drives the rear wheels and propeller via a gear mechanism, etc. (in that case, the prime mover 3 behind the propeller becomes the gear room). [Example 2]

[0017] Example 2 is shown in Figure 6. Two thrusters 2 (ducted propellers) are housed in an outer cylinder 1 with a rectangular flow channel cross-section. Furthermore, the thrusters 2 are mounted further to the rear of the vehicle body 12 than in Example 1, preventing them from flying out from the top surface of the vehicle body. The effects in this example are as follows. In this example, the enlargement of the flow channel cross-sectional area of ​​the diffuser section 5 of the outer cylinder 1 is achieved solely by the inclined section 13 at the rear of the top surface of the vehicle body. ▲1▼The flow path from the inlet of the outer cylinder 1 to the inlet of the thruster 2 is a constricted flow path, so the flow path cross-sectional area decreases (if the respective cross-sectional areas are Ai and Am, then in this example Ai / Am=2). As a result, the incoming flow is accelerated, its turbulence is reduced, and it is rectified before flowing into the thruster. In addition, the boundary layer that has developed on the upper surface of the vehicle body 12 is thinned by this accelerated flow (and in severe cases, it becomes a laminar flow), which can suppress further development and separation. If necessary, boundary layer control as described below will be performed. • Small wings 9 (marked by the dashed line ▲1▼, with a width less than or equal to the width of the outer cylinder 1) are attached to the inclined starting point of the upper rear of the vehicle body at an angle that accelerates the flow in its vicinity, thereby thinning the boundary layer. A boundary layer suction and separation plate 8 (marked with a dashed line ▲2▼, its width being less than or equal to the width of the outer cylinder 1) is installed near the vehicle body and extending in the flow direction to near the inlet of the propulsion unit 2 to suction and separate the boundary layer flowing into the outer cylinder 1. ▲2▼The thrust of a propeller is proportional to its flow rate and the velocity difference between the inlet and outlet. By creating a restricted flow path at the inlet of the outer cylinder 1 as described in ▲1▼, the flow rate flowing into the propulsion device 2, such as a ducted propeller, can be increased compared to the case without the outer cylinder 1, thereby increasing the thrust (Claim 3). ▲3▼The front half 21 of the upper surface of the outer cylinder 1 is airfoil-shaped, which offers the following advantages. If the upper front half 21 were flat, it would generate significant air resistance due to the large angle of attack against high-speed flow at speeds of approximately 200 km / h to 700 km / h. However, because it is airfoil-shaped, it generates less air resistance and also generates lift. • The thickness of section 21 can be increased, allowing the radiator 6 to be housed inside. Furthermore, because a large space can be secured, increasing the capacity and size of the radiator 6 for increasing the output of the prime mover 3 is structurally and fluidly (in terms of air resistance) easier. • When the flying car's flight speed is high and the propeller airflow is high, the flap 11 located at the rear of section 21 can be opened to adjust the airflow. ▲4▼During takeoff and landing, a portion of the air that has gained high energy through acceleration and pressurization within the outer cylinder 1 is taken in through the air intake 23 (whose width is smaller than that of the outer cylinder 1) and ejected to the leading edge negative pressure surface side of the flap 11 of the main wing 10 as shown in Figure 4. Due to the Coanda effect of the wall jet, it flows along the negative pressure surface even at a large downward angle, generating a large lift (Claim 2. Boundary layer control with a mechanism similar to that of a VTOL aircraft). ▲5▼During landing, this high-energy air can be directed to the underside of the vehicle and used for cushioning and shock absorption. The structure and mechanism are equivalent to an air-bearing type hovercraft, but the skirt for this purpose is the thin plate side plate 22 on the underside of the vehicle as shown in Figure 4. The plate 22 is attached all around, but the front and rear of the vehicle are closed during flight. [Explanation of Symbols]

[0018] 1. Outer cylinder 2 Propulsion machine 3. Engine 4. Propulsion system with a prime mover 5. Diffuser section 6. Radiator 7 Horizontal partition plate 8. Boundary layer suction separation plate 9 small wings 10 Main Wing 11 Flap 12 car bodies 13. Sloping section at the rear of the upper surface of the vehicle body 14 Vertical stabilizer 15 High speed flow 16. Radiator cooling flow 17 Horizontal partition plate (bent thin sheet) 18 Horizontal partition plate (airfoil type) 19 Rudder 20 Horizontal stabilizer 21. Upper front half of the outer cylinder (airfoil shape) 22 Lower side panel of the vehicle body 23 Air intake

Claims

[Claim 1] A propulsion system for use in an air-to-land vehicle, characterized in that the outer cylinder has a flow channel cross-sectional shape that is a combination of multiple circles, straight lines or arcs and straight lines or free curves, and is installed at any location on the upper and lower sides of the vehicle body or on the upper and lower sides of the main wing, and comprises one or more thrusters and their auxiliary equipment installed inside the outer cylinder, and is provided with an inlet of the outer cylinder having a larger flow channel cross-sectional area than the outer cylinder in the part of the outer cylinder in which the thrusters are installed, thereby creating a constricted flow channel in which the flow channel cross-sectional area decreases from the inlet of the outer cylinder to the inlet of the thruster, thereby increasing the flow rate into the thruster and increasing the thrust force, and is provided with a flap in front of the thruster that opens when the flow rate into the thruster increases to vary the flow rate into the thruster.

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