New Reductions of the Unsteady Axisymmetric Boundary Layer Equation to ODEs and Simpler PDEs
Abstract
:Contents
- 1. Introduction
- 1.1. Introduction
- 1.1. Preliminary Remarks
- 1.2. The Main Results
- 2. Reduction of the Burgers Equation
- 3. Reduction of the Steady-State Plane Boundary Layer Equation
- 3.1. Basic Equation
- 3.2. Construction of Reductions
- 3.3. The Existence of non-Symmetry Reductions
- 4. Reductions of the Unsteady Axisymmetric Boundary Layer Equation
- 4.1. Basic Equation
- 4.2. Reductions to simpler PDEs (Two-dimensional Reductions)
- 4.3. Reductions to ODEs (One-dimensional Reductions
- 5. Conclusions
- Refrences
1. Introduction
1.1. Preliminary Remarks
1.2. The Main Results
2. Reductions of the Burgers Equation
- Each equation of the system of Equation (12) is equivalent to the condition that the Jacobian of its left-hand side and the function is equal to zero. As a result, we can derive an overdetermined system of equations for determining the unknown functions , and (-system). -system is not presented here because of its cumbersomeness.
- Consider the auxiliary functions , and defined by the relationsFinding the auxiliary functions, we find the reductions. As was noted in [5], the following transformations map a reduction of the form found in (8) into a reduction:
- Finding the derivatives , and from the relations in (13) and substituting them into the -system, we obtain the following overdetermined system of equations for determining the auxiliary functions:
- The overdetermined system of Equation (15) is easy to solve. The auxiliary functions , and are used to construct reductions.
3. Reductions of the Steady-State Plane Boundary Layer Equation
3.1. Basic Equation
3.2. Construction of Reductions
3.3. The Existence of Non-Symmetry Reductions
- for an arbitrary function , the basis of symmetry operators is given by
- for , where and , the basis of symmetry operators is given by
- for , where and , the basis of symmetry operators is given by
- for , where , the basis of symmetry operators is given by
- for , the basis of symmetry operators is given by
4. Reductions of the Unsteady Axisymmetric Boundary Layer Equation
4.1. Basic Equation
4.2. Reductions to Simpler PDEs (Two-Dimensional Reductions)
- 1.
- 2.
- 3.
- ,.
- 4.
- ,.
- 5.
- ,.
4.3. Reductions to ODEs (One-Dimensional Reductions)
- 1.
- 2.
- r(x),
- 3.
- 4.
- 5.
- ,.
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
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Aksenov, A.V.; Kozyrev, A.A. New Reductions of the Unsteady Axisymmetric Boundary Layer Equation to ODEs and Simpler PDEs. Mathematics 2022, 10, 1673. https://doi.org/10.3390/math10101673
Aksenov AV, Kozyrev AA. New Reductions of the Unsteady Axisymmetric Boundary Layer Equation to ODEs and Simpler PDEs. Mathematics. 2022; 10(10):1673. https://doi.org/10.3390/math10101673
Chicago/Turabian StyleAksenov, Alexander V., and Anatoly A. Kozyrev. 2022. "New Reductions of the Unsteady Axisymmetric Boundary Layer Equation to ODEs and Simpler PDEs" Mathematics 10, no. 10: 1673. https://doi.org/10.3390/math10101673