3.5 Complex Targets. Calculation Technique of Scattering …
47
Table 3.4 RCS of airplane separate parts
Element
RCS of element separate parts nta Designation of element separate parts and
its substituted bodies
Engines
A 1
A 2
A 3
A 4
First engine
Second engine
Third engine
Fourth engine
Wing panels
A 5
A 6 = A 5
A 7
A 8 = A 7
A 9
A 10 = A 9
Leading edge part of left wing is
substituted with circular cylinder of 6.25
length and 0.15 m radius
The same leading edge part of right wing
Mid-part of left wing edge is substituted
with circular cylinder of 6.75 length and
0.125 m radius
The same edge part of right wing
Leading edge end-part of left wing is
substituted with circular cylinder of 6.75
length and 0.075 m radius
The same edge part of right wing
Fuselage
A 11
Front part of airplane is substituted with
prolate spheroid with semi-axis, equal to
1.92 m and 8.25 m
Tail assembly A 12
A 13 = A 12
A 14
Leading edge of left horizontal plane is
substituted with circular cylinder of 6.5 m
length and 0.1 m radius. Cylinder is
oriented at 133° angle to fuselage axis
The same edge of right horizontal plane
Leading edge of vertical plane is
substituted with circular cylinder of 7.5 m
length and 0.1 m radius
This table data show that we managed to approximate the most elements by simple
bodies, the approximated analytical RCS expressions of which are known. In view
of this, we should consider A 5 … A 14 as known values for each value of observation
angle from nose heading angles (forward of the beam) sector. Values A 1 … A 4 are
not expressed in analytical form; however, there are special calculation programs on
computers for their determination.
The final calculation stage concludes in joining of RCS values of separate elements
for determination of resulting RCS of an airplane. If we conduct joining according
to random phase method, then airplane RCS average value is defined as follows:
A n (γ i ) =
1
14
N
i=1
A n (γ i ), i = 1, P.
(3.59)
At the same time, an interval of assumed RCS values of airplane model equals to:
47
Table 3.4 RCS of airplane separate parts
Element
RCS of element separate parts nta Designation of element separate parts and
its substituted bodies
Engines
A 1
A 2
A 3
A 4
First engine
Second engine
Third engine
Fourth engine
Wing panels
A 5
A 6 = A 5
A 7
A 8 = A 7
A 9
A 10 = A 9
Leading edge part of left wing is
substituted with circular cylinder of 6.25
length and 0.15 m radius
The same leading edge part of right wing
Mid-part of left wing edge is substituted
with circular cylinder of 6.75 length and
0.125 m radius
The same edge part of right wing
Leading edge end-part of left wing is
substituted with circular cylinder of 6.75
length and 0.075 m radius
The same edge part of right wing
Fuselage
A 11
Front part of airplane is substituted with
prolate spheroid with semi-axis, equal to
1.92 m and 8.25 m
Tail assembly A 12
A 13 = A 12
A 14
Leading edge of left horizontal plane is
substituted with circular cylinder of 6.5 m
length and 0.1 m radius. Cylinder is
oriented at 133° angle to fuselage axis
The same edge of right horizontal plane
Leading edge of vertical plane is
substituted with circular cylinder of 7.5 m
length and 0.1 m radius
This table data show that we managed to approximate the most elements by simple
bodies, the approximated analytical RCS expressions of which are known. In view
of this, we should consider A 5 … A 14 as known values for each value of observation
angle from nose heading angles (forward of the beam) sector. Values A 1 … A 4 are
not expressed in analytical form; however, there are special calculation programs on
computers for their determination.
The final calculation stage concludes in joining of RCS values of separate elements
for determination of resulting RCS of an airplane. If we conduct joining according
to random phase method, then airplane RCS average value is defined as follows:
A n (γ i ) =
1
14
N
i=1
A n (γ i ), i = 1, P.
(3.59)
At the same time, an interval of assumed RCS values of airplane model equals to: