Custom Nose-Airplane Shape Radome

Create a copy of baseProjectHorn.nfp project and rename it as Horn_Nose.nfp. Then open it with newFASANT by clicking on File > Open or clicking twice on the project icon.

The radome considered in this section is modified ogive which resembles to the noise of an airplane. We have created its geometry by using the userFunctions utility included in newFASANT tools that allow the user to create geometries with its own Java programmed functions.

The geometry shape may be defined in two parts according to the next parameters and functions:

Parameter	a	b	c	d	e
Value	0.5	2	1.2	1.4	a*1000

Positive Y-axis half geometry definition, see Equation 1.

(1)

\begin{matrix} $ u \in [0, 1] \\ $ v \in [0, 1] \end{matrix} {\begin{matrix} x = a \cdot \cos (\frac{π \cdot $ v}{2}) \cdot \cos (π \cdot $ u) - {(\frac{$ v}{b})}^{2} \\ y = \frac{a \cdot \cos (\frac{π \cdot $ v}{2}) \cdot \sin (π \cdot $ u)}{c} \\ z = d \cdot $ v \end{matrix}

Negative Y-axis half geometry definition, see Equation 2.

(2)

\begin{matrix} $ u \in [0, 1] \\ $ v \in [0, 1] \end{matrix} {\begin{matrix} x = a \cdot \cos (\frac{π \cdot $ v}{2}) \cdot \cos (π \cdot $ u) - {(\frac{$ v}{b})}^{2} \\ y = - \frac{a \cdot \cos (\frac{π \cdot $ v}{2}) \cdot \sin (π \cdot $ u)}{c} \\ z = d \cdot $ v \end{matrix}

These functions may be used to interpolate a surface defined by its u and v parametric coordinates and using the surfaceFunction command. We recommend using it to build the same geometry.

Anyway, the next content may be copied to a text file to be imported as a newFASANT script, for example, nose_radome.nfp.

#
#   newFASANT script file to generate a Nose-Airplane shape, in milimeters
#

#required parameters
set a {0.5}
set b {2.0}
set c {1.2}
set d {1.400}
set e = 1000.0*a
#first half nose (Y-axis positive)
surfaceFunction -n id2a4dc855 -p \ #command start with main parameters
 0.0 1.0 19 \ # $u definition
 0.0 1.0 11 \ # $v definition
 "$x=a*cos(Math.PI*$v/2.0)*cos(Math.PI*$u)-Math.pow($v/b,2)" \ # x definition
 "$y=a*cos(Math.PI*$v/2.0)*sin(Math.PI*$u)/c" \ # y definition
 "$z=d*$v" \ #z definition
#second half nose (Y-axis negative)
surfaceFunction -n id5a4dc856 -p \ #command start with main parameters
 0.0 1.0 19 \ # $u definition
 0.0 1.0 11 \ # $v definition
 "$x=a*cos(Math.PI*$v/2.0)*cos(Math.PI*$u)-Math.pow($v/b,2)" \ # x definition
 "$y=-a*cos(Math.PI*$v/2.0)*sin(Math.PI*$u)/c" \ # y definition
 "$z=d*$v" #z definition
#set the second half normal vectors pointing to -Y
invertNormals -s id5a4dc856
#group the two halfs in the same object
group -s id2a4dc855 id5a4dc856 -n id31a94b3d
#scale the objects from meters to millimetres
scale -s id31a94b3d -p 1000.0

This script contains several commands:

The first section defines the required values for creating the geometry.
The second section generates two surfaces according to the formulas given previously.
The last section processes the normal vectors orientation, group the surfaces in an only object and scale it from meters to millimeters.