RU2222773C1 - Aerial rudder - Google Patents

Abstract

FIELD: rocketry, applicable as an aerial rudder of a guided rocket or missile providing its controllability and stability in the flight trajectory. SUBSTANCE: the rudder is made in the form of a rotary profiled cantilever with arrow-like front and rear edges. The front edge is formed by a straight line perpendicular to the rudder side chord, having a length making up 0.25 to 0.37 of the rudder side chord length and conjugate to it by the second straight line. The angle of inclination of the straight line relative to the rudder side chord makes up 28 to 40 deg. The angle of inclination of the rear edge relative to the rudder side chord makes up 55 to 77 deg. The length of the side chord exceeds the rudder span by 1.08 to 1.22 time. EFFECT: reduced power required for control of the missile or rocket. 2 dwg

Description

 The invention relates to the field of rocket science and can be used as the aerodynamic steering wheel of a guided projectile (CS) or rocket, ensuring their controllability and stability along the flight path.

 The expansion of the field of tactical missions and the increase in the effectiveness of the use of command and control systems and missiles predetermines a constant increase in the power of their warheads and an improvement in the control system, which leads to a tendency to increase the mass and dimensions of the command and control system and, as a consequence, the need to increase the required control efforts created by the steering organs.

At present, fully-rotating aerodynamic steering wheels (hereinafter referred to simply as the steering wheel), which provides controllability and stable motion of the CSS (rockets) both at subsonic and at supersonic flight speeds, are widely used as steering organs of US and rockets. Depending on the shape in the plan, the rational angle of deviation of the rudders is limited to 5 ... 25 ^o (at large angles of deviation, the aerodynamic efficiency of the rudders decreases sharply). In this case, the task of increasing the control effort is solved by increasing the area of the rudders, which leads to an increase in the hinged aerodynamic moment acting on them. This increases the power required to control the SS or rocket, which leads to an increase in the dimensions of the steering gear and its power source, and consequently, a deterioration in the overall mass characteristics of the SS and rockets.

прямоугольного в плане руля (кривая 1) от эффективного угла атаки (α_эф), где:

X_d - координата положения центра давления результирующей аэродинамической силы относительной передней кромки руля;
b - хорда руля;
α_эф = k_α•α+δ;
α - угол атаки УС;
δ - угол отклонения руля;
k_α - коэффициент интерференции руля и корпуса УС.A steering wheel is known that is rectangular in plan [1], a drawback of which can be considered a significant dependence of the coordinate of the position of the center of pressure of the resulting aerodynamic force along the steering chord on its steering angle and angle of attack of the control gear, which causes a corresponding increase in the aerodynamic articulated moment acting on the steering gear. Figure 1 shows the experimentally obtained when testing the model of CSS in a wind tunnel with a Mach number M = 0.7, the dependence of the change in the relative coordinate of the position of the center of pressure of the resulting aerodynamic force

rectangular in terms of steering (curve 1) from the effective angle of attack (α _eff ), where:

X _d - the coordinate of the position of the center of pressure of the resulting aerodynamic forces relative to the front edge of the steering wheel;
b - steering chord;
α _eff = k _α • α + δ;
α is the angle of attack of the DC;
δ is the steering angle;
k _α is the interference coefficient of the steering wheel and the hull CSS.

This dependence shows that with an increase in the effective angle of attack of the CS model from α _eff = 0 ^° to α _eff = 30 ^{°, the} coordinate of the position of the center of pressure of the resulting aerodynamic force on the steering wheel, rectangular in plan, shifts from the leading edge by a distance X _d = 0.135 • b.

 The steering wheel with a triangular profile in plan [2], made in the form of a profile swivel console with arrow-shaped front and rear edges, is closest to the claimed combination of essential features.

Curve 2 in FIG. 1, obtained under the same conditions for a rudder-shaped steering wheel, indicates a displacement of the center of pressure of the resulting aerodynamic force by a distance X _d = 0,049 • b to its leading edge.

 Given the opposite direction of the displacement of the coordinate of the position of the pressure center of the resulting aerodynamic force for the rectangular and triangular in terms of rudders, it can be assumed that their combination will reduce the displacement of the coordinate of the position of the center of pressure with a change in the angle of attack of the US and the angle of deviation of the combined rudder.

 The objective of the present invention is to reduce the power required to control the CSS or rocket by reducing the aerodynamic load on the steering gear.

To solve the problem in an aerodynamic steering wheel, made in the form of a rotary profile console with swept leading and trailing edges, the leading edge is formed by a straight, perpendicular to the side chord of the steering wheel and having a length of 0.25 ... 0.37 of the length of the side chord of the steering wheel and with it a second straight line, the angle of inclination of which relative to the side chord of the steering wheel is 28. ..40 ^o , while the angle of inclination of the trailing edge relative to the side chord of the steering wheel is 55 ... 77 ^o , and the length of the side chord is 1.08 ... 1 22 times the reach of the steering wheel.

 In FIG. 2 shows the shape in terms of the claimed aerodynamic steering wheel mounted on a cylindrical housing CSS.

Along body 1УС there is an onboard chord (b) of the steering wheel 2, the axis 3 of which is mounted directly in the housing 1. The front edge of the steering wheel is formed by two straight lines: the first (z) is conjugated with the onboard chord, perpendicular to it and has a length equal to 0.25 ... 0.35 of the length of the side chord of the steering wheel; the second is associated with the first straight line and with the end chord of the steering wheel (b _k ) and has an angle of inclination relative to the side chord φ = 28 ... 40 ^o . The angle of inclination of the trailing edge of the steering wheel relative to the side chord is φ = 55 ... 77 ^o . The length of the side chord (b) is 1.08 ... 1.22 times the rudder span (L).

Thus, the claimed aerodynamic steering wheel in terms prikorpusnoy consists of a rectangular part, wherein with increasing α _eff coordinate position of the center of pressure of the resultant of aerodynamic forces is shifted toward the trailing edge and the end triangular portion where the offset position coordinates of the center of pressure occurs in the opposite direction. According to the results of the study of the claimed aerodynamic steering wheel as part of the CSS model in a wind tunnel, the most complete mutual compensation of the displacement of the coordinate of the pressure center position on the rectangular and triangular parts occurs at a certain ratio of the areas of these parts, which is determined by the above dependencies, which make it possible to construct the claimed steering wheel in plan.

 Figure 1 in comparison with the previously considered dependencies 1 and 2 shows the similar dependencies 3 and 4 for the claimed aerodynamic steering wheel, which determine the zone of a possible change in the coordinates of the position of the pressure center at the above scatter of its geometric parameters. The presence of scatter is necessary both for the assignment of technological tolerances in the manufacture of the steering wheel, and for the placement of the steering wheel as part of the control unit with specific structural and dimensional limitations of its control compartment.

 In general, the dependences shown in Fig. 1 clearly illustrate the result of solving the technical problem posed, namely, the aerodynamic steering wheel, constructed in plan as a combination of rectangular rectangular and end triangular parts, provides a decrease in the displacement of the coordinate of the pressure center of the resulting aerodynamic force depending on the angle of its deviation and angle of attack US. This ensures a reduction in the aerodynamic hinge moment acting on the steering drive and, consequently, a reduction in the power required to control the CSS or rocket.

Sources of information
1. N.F. Krasnov, V.N. Kosheva. Control and stabilization in aerodynamics. - M.: Higher School, 1978, p. 244 (Fig. 3.1.2).

 2. Ibid., P. 251 (Fig. 3.1.4).

Claims (1)

The aerodynamic steering wheel, made in the form of a rotary profile console with swept front and rear edges, characterized in that the front edge is formed by a straight, perpendicular to the side chord of the steering wheel and having a length of 0.25 ... 0.37 of the length of the side chord of the steering wheel, and the second straight line associated with it, the angle of inclination of which relative to the steering chord of the steering wheel is 28 ... 40 °, while the angle of inclination of the rear edge relative to the steering chord of the steering wheel is 55 ... 77 °, and the length of the side chord is 1.08 ... 1.22 times the reach of the steering wheel.

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