RU132775U1 - NORMAL SCHEME PLANE - Google Patents

Abstract

A normal circuit aircraft containing a fuselage, a power plant, a wing with mechanization, tail vertical and horizontal tail (GO) and landing gear; the point of application of the increment of the wing lift from the released mechanization F is within the range of 0 ... 0.3 of the average aerodynamic chord of the wing in front of the center of mass (CM) of the aircraft, characterized in that the relative area of GO is calculated from the condition of balancing the aircraft with the wing mechanization fully released and angle of attack of the wing, which corresponds to the maximum allowable in this configuration, taking into account the coefficient of braking of the air flow k before GO, according to the formula: where is the coefficient of lift of the wing with the gear removed and corresponding to the maximum allowable angle of attack of the wing when it is separated from the runway or when the runway touches the landing when mechanization is issued; - the lifting force coefficient of the aircraft equal to the maximum allowable value for the aircraft as a bearing surface, taking into account the margin; - the coefficient of additional lifting force of the wing with the machinery released, corresponding to the maximum allowable angle of attack of the wing α at separation from the runway or touching the runway at landing with the mechanization released; - the relative distance from the CM to the point of application of the additional lifting wing forces when mechanization is launched; - relative distances from the CM to the point of application of the wing lifting force when the mechanization and GO are removed, respectively; k is the drag coefficient of the flow (reducing the pressure head) in front of the GO; - the relative area of the horizontal tail; S is the wing area; S- the area of horizontal plumage; and the required amount of elongation GO is determined by the value of n

Description

The utility model relates to aircraft, in particular to aircraft heavier than air. The primary field of application of the proposed utility model is passenger or military transport aircraft.

State of the art

Known patent US 2011/0180672 A1, 2011, "Aircraft with a layout that is protected from stall, and normal stability characteristics." A general-purpose aircraft has a direct sweep wing with a sharp leading edge, and a stabilizer with a rounded leading edge. Both bearing surfaces create positive lift. If the aircraft exceeds the designated maximum angle of attack on the wing due to the sharp edge, the flow stalls and the lift decreases, and the stabilizer lift does not change, due to this a dive moment appears, which reduces the angle of attack of the aircraft. The aim of the invention is to protect the aircraft from stalling. However, the sharp leading edge degrades the profile and wing characteristics and leads to a decrease in aerodynamic quality during cruising and does not improve the take-off and landing characteristics of the aircraft.

The patent SU 1828630 A3 "Aircraft of a normal circuit" is known, containing a fuselage, a power plant, a wing with mechanization and a tail unit, characterized in that in order to increase the lifting force during takeoff and landing with the released mechanization of the wing while maintaining static stability, the center of mass is located on a distance of 0 ... 30% of the MAR from the coordinate of the point of application of the increment of the lifting force with the mechanization released, where the MAR is the average aerodynamic chord of the wing.

At the same time, as follows from the description, the aircraft must be statically stable, which reduces the maximum achievable aerodynamic quality in the cruising configuration, since it is known that balancing quality losses are greater, the greater the static stability and, accordingly, the more forward position of the center of mass (CM) aircraft, and instability allows you to increase it (figure 1.).

в пределах ±20% от значений соответствующих коэффициентов для крыла, при этом площадь ГО S₂, необходимо для обеспечения заданной величины производной продольного момента по углу атаки

определяется по следующей формуле:Known application for invention 95120691/11 "Aircraft" containing a fuselage, a power plant, a wing with mechanization, tail vertical and horizontal tail and landing gear, characterized in that the point of application F ₃ increments of the lifting force of the wing from the issued mechanization is in the range 0 ... 0 3 mean aerodynamic chord b _a wing center of mass ahead of the aircraft, and the horizontal tail (HT) arranged elongation values ensuring its maximum coefficient of lift C _ymax and derivative lift coefficient of carbon attack

within ± 20% of the values of the corresponding coefficients for the wing, while the area of GO S ₂ is necessary to ensure a given value of the derivative of the longitudinal moment with respect to the angle of attack

determined by the following formula:

,

,

where: S ₁ , S ₂ - the area of the wing and horizontal tail, respectively;

,

- производные коэффициентов подъемной силы по углу атаки для крыла и горизонтального оперения соответственно;

,

- derivatives of the lifting force coefficients with respect to the angle of attack for the wing and horizontal tail, respectively;

,

- относительные величины плеч крыла и горизонтального оперения соответственно.

,

- the relative values of the wing shoulders and horizontal tail, respectively.

, то есть заданной степени статической устойчивости самолета, что не обеспечивает оптимальности ни по величине аэродинамического качества в крейсерском полете, ни по величине C_ymax на режимах взлета и посадки.In this application, the calculation of the GO area is carried out only on the basis of ensuring a given value of the derivative of the longitudinal moment with respect to the angle of attack

, that is, a given degree of static stability of the aircraft, which does not provide optimality either in terms of aerodynamic quality in cruise flight or in C _ymax in take-off and landing modes.

и удлинения λ₂ ГО производится исходя из двух условий: обеспечения заданной степени продольной статической устойчивости при заданном положении ЦМ и обеспечения максимальной величины подъемной силы самолета при выпущенной механизации при данной площади ГО.The technical result, which the utility model aims to achieve, is to increase the aerodynamic quality of the aircraft at cruising flight modes, which will reduce fuel consumption, for example, of a long-haul aircraft, and increase the lift coefficient of the aircraft at take-off and landing modes, which will reduce speeds and distances takeoff and landing. For this, the choice of relative area values

and lengthening λ ₂ GO is based on two conditions: to ensure a given degree of longitudinal static stability at a given position of the CM and to ensure the maximum lifting force of the aircraft with mechanization issued at a given area of GO.

To achieve the named technical result in the proposed utility model, the aircraft has a “normal” scheme containing the fuselage, powerplant, wing with mechanization, tail vertical and horizontal tail (GO) and landing gear, point F ₃ - application of the increment of the lift force of the wing from the issued mechanization - is in the range 0 ... 0.3 of the average aerodynamic chord b _{A of the} wing in front of the center of mass (CM) of the aircraft, the relative area of GO is calculated from the condition of balancing the aircraft with fully released mechanization to the snout and the angle of attack of the wing, corresponding to the maximum allowable in this configuration, taking into account the decrease in the pressure head k _q before the GO, according to the formula:

коэффициент подъемной силы крыла при убранной механизации, соответствующий максимально допустимому углу атаки крыла при отрыве от ВПП или касании ВПП на посадке при выпущенной механизации;Where:

the lift coefficient of the wing with retracted mechanization, corresponding to the maximum allowable angle of attack of the wing when it is separated from the runway or touched the runway at landing with the mechanization released;

- коэффициент подъемной силы ГО, равный максимально допустимому значению для ГО как несущей поверхности с учетом запаса;

- GO lifting force coefficient equal to the maximum allowable value for GO as a bearing surface, taking stock into account;

- коэффициент дополнительной подъемной силы крыла при выпущенной механизации, соответствующий максимально допустимому углу атаки крыла α_m1 при отрыве от ВПП или касании ВПП на посадке при выпущенной механизации;

- the coefficient of additional wing lift when mechanization is released, corresponding to the maximum allowable angle of attack of the wing α _m1 when leaving the runway or when the runway touches landing when mechanization is released;

- относительное расстояние от ЦМ до точки приложения дополнительной подъемной силы крыла при выпущенной механизации;

- the relative distance from the CM to the point of application of additional lifting force of the wing with the issued mechanization;

,

- относительные расстояния от ЦМ до точки приложения подъемной силы крыла при убранной механизации и ГО соответственно;

,

- the relative distances from the CM to the point of application of the lifting force of the wing with retracted mechanization and civil defense, respectively;

k _q is the drag coefficient of the flow (reduction of the pressure head) before GO;

- относительная площадь горизонтального оперения;

- the relative area of the horizontal tail;

S ₁ - wing area;

S ₂ - the area of horizontal plumage;

, которую рассчитывают из условия обеспечения требуемой величины производной продольного момента по углу атаки

при заданном положении ЦМ и с учетом коэффициента торможения потока по формуле:and the necessary amount of GO elongation λ ₂ is determined by the derivative of the GO lifting force coefficient with respect to the angle of attack of GO

, which is calculated from the condition of ensuring the required value of the derivative of the longitudinal moment with respect to the angle of attack

at a given position of the CM and taking into account the drag coefficient of the flow according to the formula:

,

- производные коэффициентов подъемной силы по углу атаки крыла и горизонтального оперения соответственно;Where:

,

- derivatives of the lifting force coefficients with respect to the angle of attack of the wing and horizontal tail, respectively;

ε ^α is the derivative of the bevel of the stream before the horizontal tail in the angle of attack of the aircraft;

- необходимая величина производной продольного момента по углу атаки при заданном положении ЦМ самолета;

- the required value of the derivative of the longitudinal moment with respect to the angle of attack at a given position of the airplane’s CM;

,

- относительные расстояния от ЦМ до аэродинамического фокуса крыла и горизонтального оперения соответственно.

,

- relative distances from the CM to the aerodynamic focus of the wing and the horizontal tail, respectively.

выбирают необходимое удлинение ГО λ₂.In this case, static instability of the aircraft is allowed. Then according to

select the required elongation of GO λ ₂ .

Thus, the parameters of the horizontal tail of the aircraft — area and elongation — are selected from the conditions:

- providing a given degree of longitudinal static stability at a given position of the CM;

- ensuring the maximum value of the lifting force of the aircraft with the mechanization issued at a given area of civil defense.

The proposed utility model is illustrated by drawings.

- figure 1 shows the dependence of the aerodynamic quality of the aircraft on the lift coefficient and the position of the CM (margin of static stability);

- figure 2 schematically shows a General view of the proposed aircraft, which indicates the main functional elements, points, a diagram of the forces acting on it, where:

1 - aircraft fuselage;

2 - power plant;

3 - wing;

4 - mechanization (flap or flap flap);

5 - vertical plumage;

6 - horizontal plumage.

G is the weight of the aircraft;

C.M. - the center of mass of the aircraft;

D ₁ - center of pressure of the wing with retracted mechanization;

D ₂ - center of pressure of GO;

This figure shows a diagram of the shoulders (distances from the points of application of forces to the CM) and the forces acting on the aircraft in cruising mode.

Y ₁ , Y ₂ - the lifting forces of the wing and GO;

l _d1 , l _d2 is the distance from the CM to the point of application of the lifting force of the wing with retracted mechanization and civil defense.

, где:- figure 3 presents a diagram of the shoulders and forces for calculating the value of the coefficient

where:

F ₁ - aerodynamic "focus" of the wing by the angle of attack of the wing;

F ₂ - aerodynamic "focus" GO on the angle of attack GO;

ΔY ₁ , ΔY ₂ - increment of the lifting force of the wing and GO along the angle of attack;

l _f1 is the distance from the CM to the aerodynamic focus of the wing;

l _f2 is the distance from the CM to the aerodynamic focus of the GO;

- figure 4 presents a diagram of the shoulders and forces acting on the aircraft with the mechanization of the wing released on take-off or landing, where:

G is the weight of the aircraft;

C.M. - the center of mass of the aircraft;

D ₁ - center of pressure of the wing with retracted mechanization;

D ₂ - center of pressure of GO;

Y ₁ - the lifting force of the wing;

Y ₂ - lifting force GO;

Y ₃ - increment of the lifting force of the wing with the released mechanization;

l _d1 - distance from the CM to the point of application of the lifting force of the wing with retracted mechanization;

l _d2 is the distance from the CM to the point of application of the lifting force of the horizontal tail;

l _f3 is the distance from the CM to the point of application of the increment of the lifting force of the wing when mechanization is released.

несущей поверхности от отношения

, где λ - удлинение, а χ - стреловидность; по которому вычисляется удлинение ГО по величине коэффициента- figure 5 presents a graph of the experimental dependence of the coefficient

bearing surface from relationship

where λ is the elongation and χ is the sweep; by which the elongation of GO is calculated by the value of the coefficient

- figure 6 presents a diagram of the relative shoulders of the aircraft forces for an example of calculating the parameters of GO according to the proposed algorithm.

C.M. - the center of mass of the aircraft;

F ₁ - aerodynamic "focus" of the wing by the angle of attack of the wing;

F ₂ - aerodynamic "focus" GO on the angle of attack GO;

F ₃ - aerodynamic "focus" of the wing on the deviation of mechanization (the point of application of the increment of the lifting force from the release of mechanization).

D ₁ - center of pressure of the wing with retracted mechanization;

D ₂ - the center of pressure of GO.

Implementation of a utility model.

The aircraft contains a fuselage 1, a power plant 2, a wing 3, a mechanization element 4, a tail vertical 5 and a horizontal tail 6 (GO) and a landing gear 7, (see figure 2). The mechanization element is structurally connected to the wing and is in the retracted position when the aircraft is in any flight mode, except for takeoff and landing. Its layout is carried out in such a way that the point F _{3 of the} application of the increment of the lifting force of the wing from the released mechanization 4 is within 0 ... 0.3 of the average aerodynamic chord b _{A of the} wing in front of the center of mass (CM) of the aircraft. This is achieved by appropriate distribution of the weights of aircraft equipment, fuel and payload. However, the area and elongation of the horizontal tail 6 of the aircraft are selected in such a way as to provide a given degree of longitudinal static stability at a given position of the CM and the maximum lifting force of the aircraft with mechanization released for a given area of GO.

Due to the fact that the range of positions of the CM is located at 45 ... 70% b _A , GO creates a positive lift in cruising modes, which leads to an increase in the aerodynamic quality of K. An example of the influence of the position of the CM on the value of K is shown in FIG.

The equations for choosing the parameters of GO have the following form:

(фиг.3):- providing a given degree of longitudinal static stability

(figure 3):

;

;

- balancing equation for take-off or landing (figure 4):

;

;

Where:

- коэффициент подъемной силы крыла при убранной механизации, соответствующий максимально допустимому углу атаки крыла α_m1 при отрыве от ВПП или касании ВПП на посадке при выпущенной механизации;

- wing lift coefficient with retracted mechanization, corresponding to the maximum allowable angle of attack of the wing α _m1 when leaving the runway or touching the runway during landing with the mechanization released;

- коэффициент подъемной силы ГО, равный максимально допустимому значению для ГО, как несущей поверхности, с учетом запаса;

- GO lifting force coefficient equal to the maximum permissible value for GO as a bearing surface, taking into account the margin;

- коэффициент дополнительной подъемной силы крыла при выпущенной механизации, соответствующий максимально допустимому углу атаки крыла α_m1 при отрыве от ВПП или касании ВПП на посадке при выпущенной механизации;

- the coefficient of additional wing lift when mechanization is released, corresponding to the maximum allowable angle of attack of the wing α _m1 when leaving the runway or when the runway touches landing when mechanization is released;

,

- относительные расстояния от ЦМ до аэродинамического фокуса крыла и горизонтального оперения соответственно;

,

- relative distances from the CM to the aerodynamic focus of the wing and the horizontal tail, respectively;

,

- относительные расстояния от ЦМ до точки приложения

,

- relative distances from the CM to the point of application

wing lift with retracted mechanization and GO, respectively;

,

- производные коэффициентов подъемной силы по углу атаки крыла

,

- derivatives of the lift coefficients with respect to the angle of attack of the wing

and horizontal plumage, respectively;

ε ^α is the derivative of the bevel of the stream before the horizontal tail in the angle of attack of the aircraft;

- требуемая величина производной продольного момента по углу атаки при заданном положении ЦМ самолета.

- the required value of the derivative of the longitudinal moment with respect to the angle of attack at a given position of the airplane’s CM.

k _q is the drag coefficient of the flow (reduction of the pressure head) before GO;

- относительная площадь горизонтального оперения.

- the relative area of the horizontal plumage.

From the balancing equation, we obtain formula (1) for calculating the relative area of civil defense during take-off or landing. In this case, c _y2m is taken equal to the maximum allowable value for GO as a bearing surface, taking into account the margin.

ГО. По величине

, с помощью известной зависимости

(фиг.5.) находим величину удлинения ГО λ₂.From the equation for providing a given degree of longitudinal static stability, we obtain formula (2) for calculating the required value

GO. In size

using a known dependency

(Fig.5.) we find the magnitude of the elongation of GO λ ₂ .

(большой степени статической устойчивости) потребная величина

может получиться слишком большой: либо потребуется очень большое удлинение ГО, что приведет к его большому весу и сложности изготовления, либо вообще окажется практически нереализуемой. В этом случае необходимо увеличить значение

для уменьшения

. Для упрощения выбора можно по формуле (2) построить график зависимости

, на котором выбирается точка с наиболее приемлемым в данном случае сочетанием значений

и

.With a large negative value

(high degree of static stability) required value

it may turn out to be too large: either a very large elongation of the GO is required, which will lead to its great weight and complexity of manufacture, or it will turn out to be practically unrealizable. In this case, increase the value

for decreasing

. To simplify the selection, it is possible to construct a dependency graph using formula (2)

where the point with the most appropriate combination of values in this case is selected

and

.

In all flight modes, including during take-off and landing, the power plant 2 creates the necessary thrust for the wing 3 to create the lifting force Y ₁ , the horizontal tail creates a lifting force Y ₂ , the sum of the moments of these forces relative to the CM is zero. To increase the coefficient of lift of the wing 3 is discharged mechanization element 4. Consequently, on the wing 3 at the point F ₃ occurs increment wing lift force Y _3. To compensate for the moment from the force Y _{3 the} lifting force of the horizontal tail must be increased by ΔY ₂ , for example, by deflecting the elevator. The force Y _{2 is} always directed vertically upward, therefore, the overall lift coefficient of the aircraft increases (see figure 3), which also leads to an increase in the aerodynamic quality K.

, рассчитывают по формуле (2), и затем по зависимости

(фиг.5) определяют необходимое удлинение ГО λ₂. При этом допускается статическая неустойчивость самолета.In order for the increase in lift on takeoff or landing to be as possible as possible for a given GO area, the GO area must be calculated using formula (1) with a value of c _y2m equal to the maximum allowable value for GO as an aerodynamic surface, taking into account the margin. The required value of the coefficient

calculated by the formula (2), and then according to

(figure 5) determine the required elongation of GO λ ₂ . In this case, static instability of the aircraft is allowed.

Calculation Example

We calculate the necessary GO parameters for the simplified case, neglecting the influence of the fuselage. We accept for the wing and GO the following initial aerodynamic data:

;

; ε ^α = 0.3; c _y1m = 1.1; c _y3 = 1.1; c _y2m = 1.1;

;

For shoulders, we take the following values (Fig.6):

;

;

;

;

;

; k _q = 0.9.

, и

ГО так, чтобы обеспечить максимальное значение коэффициента подъемной силы C_ymax самолета на режимах взлета или посадки:Calculate the parameters

, and

GO so that to ensure the maximum value of the coefficient of lift C _{ymax of the} aircraft during takeoff or landing:

;

;

.

.

оказалась слишком большой для практической реализации, поэтому примем, что самолет будет статически неустойчив, примем новую величину

. Рассчитаем новое значение

:The resulting value

turned out to be too large for practical implementation, therefore, we assume that the plane will be statically unstable, we take a new value

. Calculate the new value

:

,

,

, то есть ГО будет иметь такое же удлинение, как и крыло (при такой же стреловидности).which is an acceptable result:

, that is, the GO will have the same elongation as the wing (with the same sweep).

Thus, the claimed utility model with the same wing parameters (area, type of take-off and landing mechanization) and the GO parameters selected in this way will allow to obtain an increase in the aerodynamic quality of the aircraft at cruising flight modes and the maximum possible lift coefficient of the aircraft for the given GO area at the modes takeoff and landing.

Claims (1)

A normal circuit aircraft containing the fuselage, powerplant, mechanized wing, tail vertical and horizontal tail (GO) and landing gear; the point of application of the increment of the lift of the wing from the released mechanization F ₃ is within 0 ... 0.3 of the average aerodynamic chord b _{A of the} wing in front of the center of mass (CM) of the aircraft, characterized in that the relative area of GO is calculated from the condition of balancing the aircraft at full mechanization of the wing and the angle of attack of the wing, corresponding to the maximum allowable in this configuration, taking into account the coefficient of braking of the air flow k _q before GO, according to the formula: $${\overline{S}}_2=\frac{c_{y\mathrm{one}m}\cdot {\overline{l}}_{dl}+c_{y3}\cdot {\overline{l}}_{f3}}{c_{y2m}\cdot {\overline{l}}_{d2}\cdot k_q},\text{(one)}$$

Where $$c_{y\mathrm{one}m}=\frac{Y_{\mathrm{one}}}{q\cdot S_{\mathrm{one}}}$$

- wing lift coefficient with retracted mechanization, corresponding to the maximum allowable angle of attack of the wing when it is separated from the runway or when the runway touches landing when the mechanization is released; $$c_{y2m}=\frac{Y_2}{q\cdot S_2}$$

- GO lifting force coefficient equal to the maximum allowable value for GO as a bearing surface, taking stock into account; $$c_{y3}=\frac{Y_3}{q\cdot S_{\mathrm{one}}}$$

- the coefficient of additional lift of the wing when mechanization is released, corresponding to the maximum allowable angle of attack of the wing α _1m when it is detached from the runway or when the runway touches landing when mechanization is released; $${\overline{l}}_{f3}=\frac{l_{f3}}{b_A}$$

- the relative distance from the CM to the point of application of additional lifting force of the wing with the issued mechanization; $${\overline{l}}_{d\mathrm{one}}=\frac{l_{d\mathrm{one}}}{b_A},{\overline{l}}_{d2}=\frac{l_{d2}}{b_A}$$

- the relative distances from the CM to the point of application of the lifting force of the wing with retracted mechanization and civil defense, respectively; k _q is the drag coefficient of the flow (reduction of the pressure head) before GO; $${\overline{S}}_2=\frac{S_2}{S_{\mathrm{one}}}$$

- the relative area of the horizontal tail; S ₁ - wing area; S ₂ - the area of horizontal plumage; and the required amount of GO elongation is determined by the derivative of the GO lifting force coefficient with respect to the GO angle of attack $$c_{y2}^{\alpha },$$

which is calculated from the condition of ensuring the required value of the derivative of the longitudinal moment with respect to the angle of attack $$m_{zn}^{\alpha }$$

at a given position of the CM and taking into account the drag coefficient of the flow according to the formula: $$c_{y2}^{\alpha }=\frac{{\overline{l}}_{f\mathrm{one}}\cdot c_{y\mathrm{one}}^{\alpha }-m_{zn}^{\alpha }}{{\overline{l}}_{f2}\cdot {\overline{S}}_2\cdot k_q\cdot (\mathrm{one}-{\epsilon }^{\alpha })},\text{(2)}$$

Where $$c_{y\mathrm{one}}^{\alpha },c_{y2}^{\alpha }$$

- derivatives of the lifting force coefficients with respect to the angle of attack of the wing and horizontal tail, respectively; ε ^α is the derivative of the bevel of the stream before the horizontal tail in the angle of attack of the aircraft; $$m_{zn}^{\alpha }$$

- the required value of the derivative of the longitudinal moment with respect to the angle of attack at a given position of the airplane’s CM; $${\overline{l}}_{f\mathrm{one}}=\frac{l_{f\mathrm{one}}}{b_A},{\overline{l}}_{f2}=\frac{l_{f2}}{b_A}$$

^_ relative distances from the CM to the aerodynamic focus of the wing and the horizontal tail, respectively; while static instability of the aircraft is allowed; then according $$c_y^{\alpha }=f(\lambda )$$

choose the necessary extension of GO.

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