RU2036822C1 - Supersonic aircraft - Google Patents

Abstract

FIELD: aeronautical engineering. SUBSTANCE: to enhance aerodynamic property of aircraft, total maximum area of cross-section (maximum mid-section) of fuselage 1, wing 2 and power plant 5 is located by 55-60% of aircraft length in direction from its nose. EFFECT: considerable reduction of wave drag and optimal flight characteristics. 3 dwg, 1 tbl

Description

 The invention relates to aviation, in particular to supersonic aircraft, for example to supersonic fighters, as well as transport aircraft.

 One of the main problems in the creation of supersonic aircraft is to ensure the minimum possible wave resistance.

 It is known that the wave resistance of an airplane is equal to the wave resistance of an equivalent body of revolution.

 The magnitude of the wave resistance depends on the configuration of the equivalent body of revolution, the value of the maximum midsection, the position of the maximum midsection along the length of the aircraft, etc.

 Supersonic airplanes and their basic geometric parameters are known (see table).

 From the table it is seen that the position of the maximum midship is at an equal and more than 62% of the length of the aircraft.

 The aircraft G-18, selected as a prototype, has a maximum midship position of 64% of the length of the aircraft and the magnitude of its wave impedance is significant, which is a drawback.

 The calculations and experimental studies have shown that the value of wave impedance depends on the position of the maximum midsection along the length of the aircraft.

 The minimum wave resistance is achieved when the maximum midship is at (55-60)% of the length of the aircraft.

 Analogous aircraft, as well as the aircraft selected for the prototype, have a maximum midship position at a larger percentage of the length and do not reach the minimum possible wave resistance.

 The aim of the invention is to increase aerodynamic quality by achieving the lowest possible wave resistance.

 This is achieved by the fact that the maximum cross-sectional area of the aircraft (maximum midship) of the wing, fuselage, power plant, is located at 55-60% of the length of the aircraft.

 Comparative analysis with the prototype shows that in the proposed aircraft, the maximum midsection is at a smaller percentage of the length of the aircraft, at the optimal distance from the nose of the aircraft, providing the lowest possible wave impedance.

 Thus, the invention meets the criteria of the invention of "novelty."

 Comparison of the invention not only with the prototype, but also with other technical solutions in the art does not allow them to identify signs that distinguish the proposed solution from the prototype, which allows us to conclude that the criterion of "significant differences".

положение максимального миделя по длине самолета;
S мидель самолета;

относительная длина самолета; на фиг.3 график изменения волнового сопротивления, выраженного отношением

, где
С_хв фактическое волновое сопротивление самолета;
C_хвопт минимальное волновое сопротивление при положении миделя на

(55-60)%
Самолет содержит фюзеляж 1, крыло 2, горизонтальное 3 и вертикальное 4 оперения и силовую установку 5.In FIG. 1 shows a projection of an airplane (plan); figure 2 graph of the "area" of the aircraft, the change in the cross-sectional areas along the length of the aircraft, where

the position of the maximum midsection along the length of the aircraft;
S midship of the aircraft;

relative length of the aircraft; figure 3 graph of the change in wave impedance, expressed as

where
With _{hv the} actual wave impedance of the aircraft;
C _hwopt minimum impedance when the midsection is on

(55-60)%
The aircraft contains the fuselage 1, wing 2, horizontal 3 and vertical 4 plumage and power plant 5.

 The change in cross sections along the length of the aircraft in the form of a graph is presented in figure 2, which indicates the position of the maximum mid-section.

 The calculated and experimental studies showed that the value of wave impedance depends on the position of the maximum mid-section along the length of the aircraft.

 The value of wave resistance has a minimum value when the position of the maximum midship is 55-60% of the length. This is due to the peculiarity of the pressure distribution in the nose and in the tail of the aircraft, which in turn depends on the angle of inclination of the surface and the intensity of the shock waves. The optimal distribution of pressure and shock waves, providing minimum wave resistance, is achieved with a maximum midship position of 55-60% of the length of the aircraft. The location of the midsection of more than 60% of the length leads to a sharp increase in wave impedance (see figure 3).

 The value of wave drag is one of the important indicators of the aerodynamic perfection of an aircraft, such as acceleration time, fuel consumption in supersonic flight modes, and flight range. Therefore, reducing wave impedance is a determining tool for improving the flight performance of an aircraft.

 The use of the invention allows to significantly reduce wave impedance and provide optimal flight performance.

Claims (1)

 A SUPERSONIC PLANE containing a fuselage with a wing and a power plant, characterized in that the total maximum cross-sectional area (maximum midsection) of the fuselage, wing and power plant of the aircraft is 55 to 60% of the length of the aircraft in the direction from its nose.

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