Natural Transform for Solving Fractional High Order Differential Equations ()
1. Introduction
The natural transform (nt), first introduced by Khan and Khan [1] as the N-transform, involved an examination of its properties and uses. Subsequently, Belgacem et al. [2] [3] established its inverse and examined further essential characteristics of this integral transform, labeling it the natural transform. The nt applications in solving symmetrical differential and integral equations, as well as in the distribution and Bohemians spaces, are discussed in [4]-[14]. This work uses the nt to provide analytical new examinations of fractional high-order differential equations. It is a universal integral transform of Sumudu (st) and Laplace transform (lt). For fractional high-order differential equations, the nt provides new inclusive fractional solutions. This paper presents a novel application of nt. It improved the earlier studies in [15]-[19] by solving high-order fractional differential equations. It helps us comprehend and explain occurrences related to fractional high-order differential equations.
2. Mathematical Preliminaries
In this section, we will go over the basic definitions and theorems of fractional derivatives and the nt:
Definition 2.1 [20]
Over the set of functions
The natural transform of the function
is defined by:
(1)
where
is the natural transformation of the time function
and the variables
and
are the natural transform variables. When
in Equation (1) converges to Laplace transform [15]-[17] and
in Equation (1) converges to Sumudu transform [18] [19], respectively defined by:
(2)
(3)
Definition 2.2 [20]
Natural-Laplace duality (NSD). If
is the natural transform and
is Laplace transform of function
in A, then:
(4)
Definition 2.3 [20]
Natural-Sumudu duality (NSD). If
is the natural transform and
is Sumudu transform of function
in A, then:
(5)
Definition 2.4 [20]
If
is the natural transform of the function
, then the natural transform of fractional derivative of order
is defined as [10]-[12]:
(6)
Definition 2.5 [20]
Convolution theorem of natural transform. If
,
are the natural transform of respective functions
,
both defined in set A then,
(7)
where
is convolution of two functions
and
.
Definition 2.6 [21]
The fractional derivative of
for
in the Caputo sense is defined by
(8)
Definition 2.7 [22]
The Mittag-Leffler function with
is defined via the series representation, valid in the whole complex plane is:
(9)
The natural transform, its inverse, and the Caputo derivative formula are valid for functions
that are at least m-times differentiable (
) and of exponential order, within admissible fractional orders
. The Caputo derivative requires
and the Laplace-Sumudu transforms rely on
being absolutely continuous, enabling the use of standard integer-order initial conditions. We chose the Caputo fractional derivative for our investigation due to these characteristics. The Caputo fractional derivative is useful for problems with non-local features and phenomena with interactions. In this sense, the equation might be compared to a memory. The memory effect is a more finely tuned aspect of the Caputo fractional derivative. It is the best tool for describing recollections. We can therefore conclude that the physical meaning of the fractional Caputo derivative is a memory indicator. The range of physical events shares many characteristics with typical ones. Finally, to replicate real-world problems, the Caputo derivative should be utilized as the fractional operator. This serves as the primary reason for incorporating the Caputo fractional-order derivative operator in various physical applications. Section 2 presents the basic definitions and theorems of fractional derivatives, and the nt. Section 3 presents the solutions to three fractional high order differential equations. The results of the study are outlined in Section 3.
3. Applications and Examples
In this section, we use the natural transform to provide general solutions for three fractional boundary value problems. Because the three chosen boundary value problems span a variety of difficulties, from straightforward linear differential equations with straightforward boundary conditions to higher-order equations and systems with or without exact solutions, they serve as representative test cases for the natural transform approach. This makes it possible to confirm how well the natural transform approach handles various differential types and complexities. The resolution of every BVP utilizing the natural transform approach is characterized by the following:
Step 1: Utilizing the natural transform technique on both sides of the BVP and streamlining the outcomes.
Step 2: Utilizing the inverse natural transformation technique on both sides of the boundary value problem.
Step 3: Plugging in
into the final outcomes of Step 2 to obtain the classical solution of the BVP and clarifying the effectiveness of the natural transform technique.
Problem 3.1 [23]
Consider a fractional Boundary Value Problem in the form below:
(10)
At
the exact solution is
. (11)
The solution
Applying nt on both sides of (10), we have
(12)
On simplifying
(13)
i.e.,
(14)
Applying the inverse nt of (14), we obtain
(15)
In the case
from (15), we have
(16)
This is the exact solution of (10) obtained via [23] (See Figure 1, Figure 2).
Figure 1. Plot of the solution of (10) at various values of
.
Figure 2. Plot of the solution of (10) at
in comparison with the exact solution obtained via [23].
Problem 3.2 [23]
Consider the following fractional Boundary Value Problem as follows:
(17)
At
the exact solution is
(18)
The solution
Applying nt on both sides of (17), we have
(19)
On simplifying
(20)
i.e.,
(21)
(22)
By partial fraction decomposition, we obtain
(23)
Then,
(24)
Applying the inverse nt of (24), we obtain
(25)
Then,
(26)
(27)
In the case
from (27), we have
(28)
i.e.,
(29)
This is the exact solution of (17) obtained by [23] (See Figure 3, Figure 4).
Figure 3. Plot of the solution of (17) at various values of
.
Figure 4. Plot of the solution of (17) at
in comparison with the exact solution obtained via [23].
Problem 3.3 [23]
Consider a fractional Boundary Value Problem in the form below:
(30)
At
the exact solution is
. (31)
The solution
Applying nt on both sides of (30), we have
(32)
On simplifying
(33)
i.e.,
(34)
(35)
Applying the inverse nt of (35), we obtain
(36)
Using convolution theorem of (36), we have
(37)
In the case
from (37), we have
(38)
This is the exact solution of (30) obtained by [23] (See Figure 5, Figure 6).
Figure 5. Plot of the solution of (30) at various values of
.
Figure 6. Plot of the solution of (30) at
in comparison with the exact solution obtained via [23].
4. Conclusion
This study illustrated a novel technique known as the natural transform. It is a general approach of Laplace transform and Sumudu transform. In numerous scientific fields, it offers fresh generic solutions for fractional high-order differential equations. To shed light on the generalization of the algorithm, we compared the outcomes of the current approaches with those of other ways such as the Laplace transform, Sumudu transform and the precise answers. The figures demonstrate the simplicity, symmetric, quality, and generalizability of the proposed algorithm. Finally, but just as importantly, the natural transform is a novel generic method that may be applied to problems in a variety of scientific fields.
Acknowledgements
The researcher would like to acknowledge the Deanship of Graduate Studies and Scientific Research at the Taif University for funding this work.