2. Contents.
>History and definition.
>Introduction.
>Application in Mechanical Engineering.
>Uses of Bessel’s function in frequency
modulation.
>Application of Bessel’s Function is
Biology.
>Kettle Drum.
>Application of Bessel’s function in daily
life.
4. Bessel’s Function:-
History:-
Bessel function was first defined by the mathematician Daniel
Bernoulli and the generalized by Friedrich Bessel in 18th century.
Definition:-
Bessel equation are the solution y(x) of differential equation
𝑥2 𝑑2𝑦
𝑑𝑥2 + 𝑥
𝑑𝑦
𝑑𝑥
+ 𝑥2
− α2
𝑦 = 0
18. Bessel function in the structure of DNA
Bessel's function is given by:
𝐽𝛼 = 𝐽𝛼(𝑥) =
(−1)𝑛
𝑛!
(𝑛 + 𝛼)! × (
𝑥
2
)(2𝑛 + 𝛼)𝐽𝛼 = 𝐽𝛼(𝑥)
=
(−1)𝑛
𝑛!
(𝑛 + 𝛼)! × (
𝑥
2
)(2𝑛 + 𝛼)
Where, variable α is called the order of the function, and the
values of n are integers.
So, now how does one plot the Bessel function? Simple, if you
want to plot the Bessel function of order zero, you plug in the
values 𝛼 = 0 and 𝑛 = 0 and then plot J as a function of 𝑥 over
some range −𝑥 to +𝑥. Next you plug in 𝛼 = 0 and 𝑛 = 1, plot
again, and add the resulting curve to the one for which n = 0, just
as curves were added together to give the Fourier sum:
19. Thus, as the order increases, the position of
the first peak of the function occurs farther
from the origin.
Francis Crick showed in his doctoral
dissertation that in the transform of a
continuous helix, the intensity along a layer
line is described by the square of the Bessel
function whose order α equals the number l
of the layer line..
Thus, the intensity of the central line,
layer line zero, varies according
to J0(x)]2J0(x)]2, which is the square
of the above equation, α = 0 (red). The
intensity of the first line above (or
below) center varies according
to J1(x)]2J1(x)]2(green), and so on..