JP2005242388A - Technical education system using flying object and flying object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a student with technical understanding at high level, by which active creation activity based on understanding of technology is made possible. <P>SOLUTION: This flying object has the following features. (1) The flying object consists of a lightweight sheet and lightweight aggregate, has face structure capable of maintaining its shape, (2) has a main plane having a positive or zero camper and a dihedral angle and a horizontal tail plane having a negative angle of elevation and (3) a tensile center of string for flying it as a kite is located in front of an aerodynamic center. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the technical field of natural science, which is difficult to understand, it relates to a technical education system that allows students to gain a high level of understanding of technology and physical function materials used in the system.

  Either textbooks and explanations by teachers, plus exercises by example.

  The level of technical understanding of students was limited to passive understanding of the contents of textbooks, and it was difficult to give students a high level of technical understanding that led to active creative activities.

  The present invention has been made to solve the above-mentioned problems of the conventional technical education system, and provides students with a high level of technical understanding that enables active creative activities based on technical understanding. With the goal.

The flying object of the present invention has the following characteristics.
(1) It consists of a lightweight sheet and lightweight aggregate, and is a surface structure that can maintain its own shape,
(2) a main wing having a positive or zero camper and an upper angle, and a horizontal tail having a negative angle of attack;
(3) A flying object in which the center of tension of the yarn for flying as a kite is located in front of the aerodynamic center.

  The flying object of the present invention can practice improved flying object creation activities through experience of designing, manufacturing, and flight experiments using the flying object, so that the level of understanding of fluid dynamics can be passively understood. It can be raised to a level where the intellectual production activity of creative activity is possible.

Reference Example 1
1. The reference example of the present invention includes the following educational process.
(1) Teacher lecture:
It is an educational process that includes fluid mechanics and the necessary mathematics and mechanics. You may omit these for students who have already learned these.
(2) Simulation learning on a computer:
Based on the basic equations of hydrodynamics, especially aircraft dynamics, the flight phenomenon is simulated using the example of the flying object, and the hydrodynamic function of the flying object is understood.
(3) Flying body design and production:
Design and produce flying objects based on the knowledge gained through lectures and simulation learning.
(4) Flight object flight experiment:
An experiment is conducted in which the flying object produced above is used as a kite. Try to improve the flight function as a kite, and learn the optimization of the flight function by repeating the design and production process in (3).

Embodiment 1 FIG.
1. Details of the flying object of the present invention The basic features of the flying object of the present invention are as follows.
(1) A surface structure consisting of a lightweight sheet and an aggregate of shape that can maintain its own shape.
(2) It has a main wing and a horizontal tail.
(3) At least the main wing has a dihedral angle.
(4) The horizontal tail has a negative angle of attack.
(5) The thread connection point for flying as a kite is ahead of the aerodynamic center. When there are a plurality of stitches, the extension point of the yarn below the stitch is set forward of the aerodynamic center.

  A typical conventional kite is a single surface structure with a negative camper (a curved surface that protrudes downward along the axis) to provide pitching stability, and has an angle of attack near 45 °. . On the other hand, the flying object used in the teaching material of the present invention has a main wing having a positive or zero camper and a horizontal tail with a negative angle of attack, and the pitching stability is given by the negative angle of attack of the horizontal tail. Yes. This flying object has a much smaller angle of attack than a conventional kite, and is a flying object close to an airplane that flies almost horizontally in a laminar flow condition. The difference from the airplane is that the airplane minimizes the lift-drag ratio and minimizes the fuel consumption, while the flying object has a large horizontal drag generated on the thread, so it is necessary to reduce the drag of the flying object itself Is small and intended only to maximize lift. For this reason, the degree of freedom of the surface shape is larger than that of an airplane, and the degree of freedom of optimization of the function as a bag is also great. In other words, it is possible to produce a more optimized airplane than a airplane diverted.

  As described above, the flying object of the present invention has dramatically improved flight performance as compared with the conventional kite. Comparing the ascent limit altitude and the like with the conventional kite, it can be confirmed that the conventional kite is greatly improved.

  The flying object of the present invention is highly optimized for the application form of a kite, and can exhibit performance close to the physical limit. In a system with many compromises such as a conventional bag, various losses exist, so that a realistic performance limit occurs at a level lower than the theoretical performance limit. Therefore, there is no opportunity to confirm the theoretical performance limit. In learning the principles of natural science, it is extremely effective to experience the performance limitations of physical functional systems with specific functional purposes through experience. To that end, the physical function system must be highly optimized with respect to the intended function.

  As described above, the flying object of the present invention is extremely effective as an aid to understanding the difficult technical field of fluid dynamics, particularly aircraft dynamics.

The configuration and function of the flying object of the present invention will be described in detail below.
1.1 Difference between new flying object (NFO) and conventional flying object This flying object is similar to a conventional kite in that it is restrained by yarn and flies in the wind. The form of formation is fundamentally different from that of conventional cocoons. In addition, since it is different from an aircraft or a glider for the reason described later, the flying object of the present invention is hereinafter abbreviated as a new flying object (NFO: an acronym for New Flying Object). Now, in the conventional typical kite, one plane inclined obliquely forward with a certain angle (attack angle) in the wind direction floats the wind pressure in the direction perpendicular to the surface, and the total wind pressure is The aircraft flies in a balanced condition that antagonizes the sum of the yarn tension and its own weight (which can be neglected compared to the total wind pressure in normal flight conditions).

  On the other hand, the flying object adopted here is a flying object close to an airplane that floats with a lift in a direction perpendicular to the wind in the wind and a drag in a horizontal direction much lower than the lift. In other words, if the wind is blowing horizontally, the vertical component of the yarn tension balances the lift and gravity of the weight (usually negligible compared to the lift), and the horizontal component of the yarn balances the drag. To fly. If a forward thrust instead of yarn tension and a load for adjusting the center of gravity are applied, the aircraft flies forward in a windless air to form a flight state similar to an airplane. Further, depending on the adjustment of the center of gravity, a thrust force that glides forward while falling with gravity as a thrust force is formed, and a flying object similar to a glider is formed. However, NFO differs from an airplane in the following points.

  Airplanes have a design goal of minimizing the lift-drag ratio (ratio of lift to drag) proportional to the fuel consumption for a given flight speed. Designing in a shape is one of the basics of design. Elliptical wings used in light aircraft and swept wings used in Boeing B747 are examples of optimal shapes.

  On the other hand, with this projectile, the goal is not to minimize drag, but to raise it high in the sky. In addition, as shown in FIG. 1, there is a drag in the wind speed direction that is applied to the yarn unlike an airplane. Generally, this drag is larger than the drag on the plane of the flying object, so that the drag of the flying object itself can be reduced. Significance is small. Therefore, in order to fly high in the sky, the basic design is to optimize the frame structure to maximize the lift rather than to minimize the drag of the surface.

  Now, when only the maximization of the lift force is obtained in this way and the goal of the drag minimization is excluded, the degree of freedom in selecting the surface shape increases. In other words, the optimum shape for NFO is different from that of an airplane. In fact, the lift-drag ratio is strongly dependent on the aspect ratio, but the lift is not necessarily dependent on the aspect ratio. For example, a Δ-shaped wing with a small aspect ratio is lifted and resisted compared to an elliptical wing with a large aspect ratio, thanks to the presence of nonlinear vortex lift (literature: Tosho, Model Aircraft and Sakai Science, Radio Experiment Co., 1992). The ratio is inferior, but the lift is rather large. By recognizing the optimal shape as a kite in this way, it is possible to design a flying object with better flight performance as a kite than using the design of an airplane.

  Thus, in NFO, unlike planes, the surface shape can be selected freely, so first create a plane shape that you want to fry, and optimize the structure of the framework toward the goal of frying high in the sky. Is the basis of design.

1.2 Conditions under which a single plane can fly In a plane structure that is generally constrained by a thread and is flying at a constant angle of attack, the following conditions are satisfied with the thread centered.
(1) The wind pressure consisting of drag + lift and tension + gravity are balanced.
(2) The moment due to aerodynamic force around the thread is balanced with the moment due to gravity.
In order to satisfy this condition, as shown in FIG. 1, the wind pressure center is that the wind pressure center should be closer to the front edge (tip) of the surface than the center of gravity, and the thread should be closer to the wind pressure center. . However, under normal flight conditions, gravity is much smaller than aerodynamic force as described above, so the above condition is
(1) The center of the thread (the point where the extension of the thread intersects the heel surface) is almost coincident with the center of the wind pressure. (2) Tension is balanced with wind pressure.
It can be replaced with simpler conditions.

In the following description, it is assumed that the wind pressure center coincides with the thread center.
Here, a plane with a large aspect ratio (aspect ratio) and no thickness, such as a bird or airplane wing, is considered a flying object. In this case, as described in Mechanical Engineering Handbook 1996, page A5-109, if the angle of attack is α, the dimensionless lift coefficient CL and the aerodynamic center (the moment by the aerodynamic force is constant regardless of the angle of attack) The moment coefficient Cmac around the point (in this case, the point at a distance of chord length ÷ 4 from the tip of the surface) is given by the following equation when α is small.
CL = 2π (Sin [α] + 2f) ------------------------ (Formula 1)

Cmac = -πf ----------------------------------------- (Formula 2)

Here, f is a quantity (camper) representing the warpage of the surface, and is obtained by dividing the height from the line connecting the leading edge and the trailing edge of the maximum swell point of the blade by the chord length. When the surface warps upwards like an airplane wing, f is positive. When the surface warps downwards like a ship bottom, f is negative.

CL and Cmac are dimensionless quantities having the following relationship with the lift L and the moment Mac (with positive trailing edge).
CL = L / (1/2 ρU ² S) ------------------------- (Equation 3)

Cmac = Mac / (1/2 [rho] U < ² > S) -------------------- (Formula 4)

Here, U is the wind speed, S is the surface area, and ρ is the air density.

Assuming that the dimensionless distance obtained by dividing the distance from the aerodynamic center to the wind pressure center and hence the thread center by the chord length is x (the trailing edge side is positive from the aerodynamic center), x is obtained from the following equation.
-XCL = Cmac
However, x is positive from the leading edge toward the trailing edge, and x = 0 at the aerodynamic center.
By substituting CL and Cmac in Equations 1 and 2 into CL and Cmac in the above equation, x can be obtained as follows.
x = f / (2 (Sinα + 2f)) ------------------------ (Formula 5)

  FIG. 2 depicts the relationship between α and x, with α on the horizontal axis and x on the vertical axis. The solid line in the figure is f = 0.01, i.e., when f is positive (used in a subsonic airplane like a positive camber wing), and the alternate long and short dash line is when f = -0.01, i.e., f is negative. is there.

  Now, looking at the characteristics of the positive camber blade, the center of wind pressure shifts to the trailing edge when the angle of attack α decreases. As a result, a moment that further reduces the angle of attack works, and the angle of attack decreases more and more. In addition, the camber-free plane does not return to its original position even if it tilts once because the moment to restore it does not work. In other words, if the camber is zero or positive, it cannot fly as it is. (Reference: “Science of Samurai” Toshiro Ito, Koji Komura, Shogakukan, 1979) This phenomenon is called “static instability phenomenon related to pitching of samurai”.

  On the other hand, on the surface of the negative camber, when α decreases, the wind pressure center moves to the leading edge side, and a moment is applied to restore α. Therefore, the plane of the negative camber can fly as it is.

  The above is true for airplanes, gliders, and wings with small aspect ratios. “The only plane that can fly without a horizontal tail is a negative camber wing.” For the reasons described above, a negative camper is given to a kite using a single plane. However, there are exceptions for specially structured Δ wings or swept wings, which will not be described. (Reference: B. Etkin & L D Reid, Dynamics of flight, p23)

1.3 Characteristics of a classic kite A classic kite is a single plane with a negative camber, such as a Japanese kite or a Dutch kite. Next, let's consider the characteristics of a classic kite with a negative camber. First, the relationship between the angle of attack and the lift when f = 0.01, f = 0 and f = −0.01 with the vertical axis and the angle of attack on the horizontal axis will be illustrated in FIG. In the figure, the solid line corresponds to f = 0.01, the dotted line corresponds to f = 0, and the alternate long and short dash line corresponds to f = −0.01. The following can be seen from the figure.
(1) In all cases, there is an angle of attack that maximizes lift. If the angle of attack exceeds this, the lift will drop rapidly. This state where the lift is reduced is called a stalled state.
(2) The maximum lift is small in the negative camber.
When stalled, the streamlines around the wings are disturbed, lowering the lift and causing the wind pressure to work perpendicular to the surface. Since the kite has a negative f, sufficient lift cannot be obtained in a laminar flow region where the angle of attack of the kite is low. Therefore, if a thread is taken at a point relatively close to the leading edge and the angle of attack is low (see FIG. 1), the lift cannot be obtained. As a result, the drag that acts on the kite wins and the kite is swept away and flies low. A kite in this state is called a ceiling kite, and it is the most disliked flight state of classic kites.

Therefore, to avoid this ceiling ridge, let's consider what happens when the yarn angle is closer to the aerodynamic center and the angle of attack is increased. 4 plots the soot pressure coefficient CT over a wider range of angles of attack, and FIG. 5 plots the vertical component CT _V of the wind pressure coefficient CT as a function of angle of attack. The reason why there is an appropriate lift and a large drag is when the angle of attack is about 45 degrees. The classic kite can be interpreted as a tug of war with humans at such a low angle of rise.

1.4 Principle of NFO NFO makes the cross-sectional camber of any plane shape zero or positive by making full use of the degree of freedom of the plane shape of the flying object constrained by the aforementioned thread. It is intended to fly using the high lift in the laminar flow region of this kind of surface. For static instability related to pitching of this type of surface, avoid the use of a framework in which a part of the surface is the main wing and the other part of the surface as far downstream as possible from the main wing wind pressure center is the horizontal tail. Yes. FIG. 9 to be described later is a case of the surface shape of a seagull and a penguin. In the figure, the hatched portion in the vertical direction is the main wing portion, and the hatched portion in the horizontal direction is the tail portion. The tail has a negative angle of attack with respect to the zero lift line of the main wing, similar to airplanes and gliders.

  In the following, the tail effect will be described for the case of f = 0 and f = 0.01. Now, suppose that the area of the main wing is S, the area of the tail is St, and the dimensionless distance (distance / chord length) from the aerodynamic center to the lift center of the tail is x. The tail portion has a negative angle of attack of i with respect to the no-lift line of the main wing, and the lift coefficient of the tail is the same as that of the main wing. It is assumed that the flow at the tail part is along the zero lift line of the main wing.

As is apparent from FIG. 7, Expression 1 that gives the lift of the main wing and Expression 2 that gives the aerodynamic center moment are changed as follows.
CL = 2π (Sin (α) − (St / S) Sin (i) + 2f) --- (Expression 6)
Cmac =-. Pi.f + 2.pi.ht (St / S) Sin (i) ---------- (Equation 7)

On the other hand, since the position x of the pressure center is given by -CLx = Cmac, Equations 6 and 7 are substituted into this to obtain the following equation that gives x.
x = (2ht (St / S) Sin (i) -f) / (2 (Sin (α)-(St / S) Si
n (i) + 2f)) ------------------------------------- (Formula 8)

7 and 8 show the lift (CL: dotted line, alternate long and short dash line) and the position of wind pressure center (thread center) with respect to the angle of attack when i = 2 degrees, St / S = 0.1, and ht = 2. (Solid line) is illustrated. In both cases of f = 0 and f = 0.01, x <0, that is, the wind pressure center is on the front edge side from the aerodynamic center, and when the angle of attack is increased, this position is in the direction of the aerodynamic center, that is, the rear edge. This indicates that there is static stability with respect to pitching because the head-lowering moment moves and the restoring force that restores the angle of attack works. In addition, in terms of lift, the lift (CL _t : dotted line) in the presence of the tail has an excellent characteristic that it hardly changes compared to the lift (CL ₀ : dashed line) in the absence of the tail. . As described above, the flying object of the present invention has the main wing caper as zero or positive, does not require pitching stability to itself, obtains only the maximum lift, and pitching stability at the negative angle of attack of the horizontal tail. In addition, by eliminating the design burden of minimizing the drag, optimization without waste is realized for the required function as a bag.

  It has been proved by aircraft mechanics that the above phenomenon is established regardless of the surface shape such as the aspect ratio of the surface. In the aircraft, the position of the center of gravity corresponds to the position of the thread.

1.5 Structure of NFO FIGS. 9 and 10 show examples of the surface shape and framework of the flying object of the present invention. Birds, insects, bats, etc. flying in nature suggest good examples of surface shapes that inspire the desire to fly. However, the appearance of penguins, fish and animals that do not fly in the natural world from the front is also a good example of a shape that stimulates the desire to fly in the sense that something unexpected will fly. However, a shape with a small aspect ratio, which is not suitable for an airplane, is also worth trying in terms of performance because it provides a large lift as an NFO shape.

  The thin plate structure of the flying body is made of non-woven fabric with high tensile impact strength and low weight per area (40 g / square meter or less), lightweight and rigid bamboo, and organic composite material (carbon fiber or glass fiber composite material). Consists of. For such materials, the surface size is preferably 0.2 square m or less made by joining two or four A4-sized non-woven fabrics, and the diameter of a round bar is in the range of 0.2 to 2 mm. Is practical. Moreover, in order to prevent bending of the natural material bamboo, it is effective to have a structure in which two pieces are laminated with the skin part on the outside. When such a material is used effectively, it is possible to form a flight surface having a main wing chord length of 20 cm or less with an area density σ of 60 g / square m or less with 0.2 square m.

Since the flying force L of the flying object is CL × (1/2) ρU ² S (derived from Equation 3) as described above, the lifting coefficient is 1, the gravitational acceleration g is 9.8, and the air density ρ is 1. Assuming .2. U> SQRT (2σg / ρ) ≈1 m / s, the flying object can be lifted even at a wind speed of 1 m / s. Furthermore, when a framework structure as will be described later is adopted, the above-mentioned lightweight kite can withstand a strong wind of 10 m / s.

  The above means that the flying object of the present invention can obtain an opportunity for NFO experiments on a daily basis without particularly selecting a day with wind and avoiding strong winds.

  In manufacturing the NFO, for example, a surface shape is created on a PC, and two or four A4-sized non-woven fabrics are printed with an ink jet printer, and these are cut out and bonded to form one surface. FIG. 9 is an example of a figure. As a figure, it is left-right symmetrical unless it is particularly elaborate. In the drawing, the hatched portion in the horizontal direction corresponds to the main wing, and the hatched portion in the vertical direction corresponds to the tail wing. Since the figure is a flying object, a simple shape that can be approximated by one or a plurality of broken lines is recommended for the front edge portion where the wind pressure is high.

The structure of NFO will be described with reference to FIG. When carbon fiber is used for the NFO aggregate, there are two types of flying objects: thick bone (1.4φ to 1.6φ for A4 × 4 sheet size) and small bone (0.8φ to 1.0φ) Is used. First, the small bones are pasted on the back side of the surface in the following order.
(1) On the center line (aa) of a symmetrical figure
(2) In the case of a figure extending horizontally like a bird as shown in FIG. 9, it is on a line (cc) parallel to the center line at a position about half the left and right of the figure.
(3) Multiple lines near the leading edge
(4) As seen in the penguin shape, the part protruding from the leading edge is reinforced with multiple small bones
(5) Oblique crossing over the small bone of the leading edge and line (aa) and line (cc)
(6) Outer edge of tail wing It is desirable that the aggregates are arranged like triangles. This is because the twisting of the flying object cannot be prevented by the arrangement in which the squares are joined. If the small bones are arranged as described above, the plane structure of the flying object is completed. However, the line (aa) and the line (cc) can still bend freely.

  Next, in the case of a bird, a main bone is prepared by joining small bones at both ends of the portion corresponding to the intersection with the line (c-c), and this is the surface, which is the surface of the small bone at the joint shown in FIG. Combined. The left and right main bones are joined by a spring as shown in FIG. The main frame is arranged in front of the seat in order to prevent the camber of the seat from becoming negative. If the main bone is attached to the back surface of the sheet as in the structure B of FIG. 11, a negative camber is formed as shown in the figure. On the other hand, if it arrange | positions on the front surface, without adhering to a sheet | seat like the structure A, a sheet | seat will not comprise a negative camber. Also, in order to prevent the lines (a-a) and (c-c) from bending to the bottom of the ship and forming a negative camper, insert a diagonal line between these lines and the bone at the leading edge. After improving the rigidity of the portion of the sheet on which these bones are pasted, these surfaces are devised to bend with the wind.

  FIG. 12 shows a state where these surfaces are broken in two due to a strong wind. As shown in the figure, there are small bones on the ridgeline of the rigid surface folded in two, so the ridgeline has extremely high rigidity and there is no fear of bending into the bottom of the ship under any strong wind. In particular, since the center line (aa) is threaded as shown in FIGS. 12 and 13, the rigidity of the center line is further increased.

  FIG. 13 shows an example of a method for forming the tail. As shown in FIG. 13, when the triangular portion that extends across the center line and opens toward the tail is folded at the center line and bonded together, the above-described negative angle of attack i can be formed. The cross-hatched portion of the figure made by bonding can form a vertical tail that helps prevent roll motion. In addition, there is a phenomenon in which a negative angle of attack is formed by wind pressure in a flight state even if the rigidity of the horizontal tail is simply reduced without actively providing a negative angle of attack on the horizontal tail. This phenomenon may be used when actually manufacturing a kite.

1.6 Features of NFO as teaching materials
(1) Simultaneous acquisition of creativity and mechanical engineering: In learning using NFO as a teaching material, students create any shape that they want to fry into the sky and apply a wide range of mechanical engineering (fluid mechanics, material mechanics, control engineering, etc.) Make full use of the structure of the flying object to give it the best performance as a kite. As a result, students can not only learn mechanical engineering extensively, but also master creativity.
(2) Acquisition of PC utilization: Since NFO uses a laminar flow region, the most complex theoretical formula of hydrodynamics among the technologies required for NFO design can be expressed by analytical functions. Therefore, all technical knowledge can be described by programs such as Mathematica and Mathcad. As a result, students can acquire technical knowledge in a form that is free from computation of mathematical formulas that are time consuming and error-prone.
(3) Not all formulas are written on paper as in the past, but are written in programs such as Mathematica and Mathcad. In addition to quantitatively examining the problem of dynamic stability, the actual behavior can be simulated on a PC.
(4) The results of learning can be confirmed by experiments. As a result, students can learn much about the significance of experiments.

Reference Example 2
Configuration of Fluid Dynamics Simulation Program The fluid dynamics simulation program used in the technical education system of the present invention has the following functions. Based on the basic equations of fluid mechanics, especially aircraft mechanics, the behavior of a moving object can be simulated, and an airplane can be handled as a moving object. In addition, it is possible to simulate the configuration of a model that reflects the difference in restraint conditions such as kites, airplanes, and gliders. It also has an interface function to efficiently input structural specifications as a kite and output flight status. The output function includes a real time display of the flying motion of the flying object, a time function display and parameter function display of the flight state index, and an effect display of the design parameter. In addition, this simulation program includes a wind simulator that simulates wind accompanied by various changes in the natural environment. By providing this simulator, it is possible to simulate an experiment in which a design example of an assumed kite actually flies in a natural environment on a computer. Since the flying object of the present invention flies under a laminar flow condition, a flight simulation can be handled as an analysis function, and a detailed analysis can be performed in a short time by a small computer (PC). Furthermore, it has a function as a textbook, and a student can efficiently learn fluid dynamics while simulating a flying object of teaching materials.

Reference Example 3
Details of learning with teaching materials
(1) Understand the fluid dynamics, especially aircraft dynamics, of the flying object of the present invention by computer simulation.
It is effective to repeat the work of changing the configuration of the flying object and confirming the change in the flight characteristics.
(2) Manufacturing the flying object Design and manufacture the flying object using the knowledge learned in the simulation. Various deformed flying objects are manufactured within the range that satisfies the basic configuration conditions. It is beneficial if multiple students produce different flying objects from each other because many deformations are obtained.
(3) Flight test of flying object A flying experiment is conducted using the manufactured flying object as a kite outdoors. We will compare the flight motion characteristics of the deformed projectiles and try to understand the relationship between deformation and flight characteristics. As an example of the learning procedure, learning can be performed efficiently by following the process described below.

  Create a hypothesis that can explain the difference in flight characteristics of the deformed flying object obtained in the experiment, produce a deformed flying object with exaggerated features corresponding to the hypothesis, and confirm the validity of the hypothesis by the flight experiment. Attempt to verify the deformation and hypothesis for each part of the projectile. Finding a direction to improve flight performance by combining a number of hypotheses and reflecting it in the design of the flying object. In this way, we will try to make an improved flying object and conduct a flight experiment.

  The knowledge obtained in the above experiment is reproduced by simulation to confirm the recognition items. According to the simulation, the flight characteristics can be confirmed without being affected by the instability of the natural environment, so that the flight performance can be improved efficiently by combining with the experiment in a complementary manner.

  By experiencing the above process, the principles of hydrodynamics can be deeply understood. In addition, the understanding of the principle can be raised to a high level that can be linked to voluntary intellectual creative activities such as the creation of flying objects with improved flight performance.

Reference Example 4
As an experiment of another form of the flying body, a weight is added to the foremost part of the flying body without using a thread to form a center of gravity ahead of the center of the buoyancy, and conditions for gliding as a glider are given. Glide experiments are conducted in the windless air using this projectile. This experiment provides an additional understanding of the flight function as a kite. It can be recognized that those who have the same wing shape have good flight performance when flying as a kite with good glide performance. However, a thing with good flight performance as a kite does not necessarily have good flight performance as a glider, and this makes it possible to recognize the difference between a flying object of the present invention and a glider or airplane.

It is a figure explaining the flying state of a kite. It is a figure which shows the positional relationship of the attack angle of a kite and a wind pressure center. It is a figure which shows the relationship between the angle of attack and lift of a kite with different campers. It is a figure which shows the relationship between the wind pressure which acts on the conventional kite, and an angle of attack. It is a figure which shows the vertical component and the angle of attack of the wind pressure which act on the conventional kite. It is a figure explaining the flight principle of the flying body with a vertical tail. It is a figure which shows the flight characteristic of a flying body with a vertical tail. It is a figure which shows the flight characteristic of a flying body with a vertical tail. It is a figure which shows the example of a shape of the flying body of this invention. It is a front view which shows the example of a shape of the flying body of this invention. It is a figure explaining the principle of the framework of the flying body of this invention. It is a figure explaining the effect | action of the framework of the flying body of this invention. It is a figure which shows the formal method of the tail of the flying body of this invention.

Explanation of symbols

  1 Main wing, 2 tail wings, 3 threads, 4 aerodynamic centers.

Claims (1)

(1) It consists of a lightweight sheet and lightweight aggregate, and is a surface structure that can maintain its own shape,
(2) a main wing having a positive or zero camper and an upper angle, and a horizontal tail having a negative angle of attack;
(3) A flying object in which the center of tension of the yarn for flying as a kite is located in front of the aerodynamic center.

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