JADEs Issue #6:  The Heat Equation

JADEs Issue #6: The Heat Equation

The following problem for this week focuses on the popular linear parabolic PDE, the Heat Equation.

PROBLEM 1

Definition

No alt text provided for this image


with u = f(x) at t = 0 over an indefinite or even infinite domain on x. So, we get the following indefinite general solution:

No alt text provided for this image



Source: H. S. Carslaw and J. C. Jaeger, Conduction of Heat in Solids,?Clarendon Press, Oxford (1986).


Example

No alt text provided for this image


with

No alt text provided for this image


at t = 0.


We can get the following general solution:

No alt text provided for this image



No alt text provided for this image



No alt text provided for this image



No alt text provided for this image


No alt text provided for this image




Example 2

Now, instead of the general or indefinite solution above, we can specify the domain x from -10 to 10 to give us a new particular solution for u(x,t):


No alt text provided for this image



No alt text provided for this image





Next, here is another linear PDE; this one involving only spatial variables (no time t). We find a particular solution u = u(x,y) instead now.

PROBLEM 2 (EXCERPT)

Definition

No alt text provided for this image


No alt text provided for this image




Example

No alt text provided for this image


No alt text provided for this image



No alt text provided for this image



No alt text provided for this image



No alt text provided for this image



No alt text provided for this image



NOTE: The arbitrary constant C in above is / should be the summation of three arbitrary constants or C_1 + C_2 + C_3. Each C results after each integration. Since this is a triple integral, there are three resulting arbitrary constants.

Source: Anglin, Linear PDEs of Constant Coefficients, Kindle Direct (2022).



ABOUT THE JOURNAL

The Journal of Applied Differential Equations, otherwise known as JADEs is a free Open Access (OA) eJournal (ISSN# pending) that covers both linear and nonlinear partial differential equations (PDEs) and ordinary differential equations (ODEs) and the analytic methods/solutions to these.

While most journals and proceedings take a very theory-driven approach to PDEs and ODEs, this journal will discuss and illustrate problems from a very pragmatic, workshop problem-solution focus for applied/industrial mathematicians, scientists (physicists, chemists, etc.), engineers (mechanical, electrical, maybe some structural), and others.

Please subscribe if you want to see more problems like the ones above as well as other more relevant PDEs and/or ODEs with applications in mechanics (analytical, classical, Newtonian), electromagnetic field/quantum-based wave mechanics, fluid mechanics and beyond. Enjoy!


ABOUT THE EDITOR

Steve Anglin, M.Sc. Ph.D. (h.c.) is an applied, industrial mathematician primarily teaching and solving partial differential equations (PDEs) with applications in the fields of fluid mechanics (mechanical engineering) as well as some electrical engineering and physics. He is a former lecturer of mathematics at Case and Saint Leo Universities. Steve received his Master of Science (M.Sc.) in applied mathematics from Brown University (Ivy League) and his Hon. Doctorate (Ph.D.(h.c.)) in mathematics from Trinity College. Previously, he published or has been credited on 2,000+ technical trade books with Springer Nature and Pearson Education as well as 2 eZines with O'Reilly Media.

For more, visit:?https://www.amazon.com/author/steveanglin

Email:?[email protected]

Vibin Jacob

18y exp in R&D Product Dev.,Thermal System(HVAC and Powertrain cooling), NVH, Vehicle Development,Testing & EV thermal.

1 年

Schrodinger wave equation Ψ - wave function, tells velocity and location of electron, E- energy, H-hamiltonian operator.The Hamiltonian operator, H ^ ψ = E ψ , extracts eigenvalue E from eigenfunction ψ, in which ψ represents the state of a system and E its energy.

回复
黄卫光

DrHuang.com, UNSW alumni

2 年

your solution is too complicated. mathHand.com can give simple solution

回复
Steve A.

2,000+ books published

2 年

Thanks for the share!

回复

要查看或添加评论,请登录

Steve A.的更多文章

  • JADEs News: Letter from the Editor

    JADEs News: Letter from the Editor

    Dear JADEs subscribers: It is with great regret that I announce the suspension of this open access Journal of Applied…

  • JADEs #33: Turbulence & PDEs, Part 2

    JADEs #33: Turbulence & PDEs, Part 2

    This article and problem, "Incompressible Isotropic Turbulent Flows", originally published by me in the 'Journal of…

  • JADEs #32: Turbulence & PDEs, Part 1

    JADEs #32: Turbulence & PDEs, Part 1

    The following journal article, "Homogeneous Turbulence and the Rate of Viscous Dissipation of Kinetic Energy &…

  • JADEs #31: Inviscid Geodynamics Equations

    JADEs #31: Inviscid Geodynamics Equations

    The following journal article "Supersonic Flows, Sound Speeds and Mach Angle from the Inviscid Goedynamics Equations"…

    1 条评论
  • JADEs #30: Equations of Motion / Euler Equation

    JADEs #30: Equations of Motion / Euler Equation

    The following articles have been excerpted from the 'Open Access International Journal of Innovation in Science and…

  • JADEs #29: Vorticity Equation & Distribution

    JADEs #29: Vorticity Equation & Distribution

    The following articles have been excerpted from the Open Access International Journal of Innovation in Science and…

  • JADEs #28: A Taylor’s Viscous Problem

    JADEs #28: A Taylor’s Viscous Problem

    This week's issue of JADEs is a syndication of an older, existing journal article on "Taylor’s Viscous Problem for…

  • JADEs #27: Riccati ODEs

    JADEs #27: Riccati ODEs

    In the final issue of 2022 of JADEs, we explore two Riccati Ordinary Differential Equations (ODEs). PROBLEM #1…

    2 条评论
  • JADEs #26: Linear Elliptic PDE

    JADEs #26: Linear Elliptic PDE

    The following problem explores a linear elliptic PDE of nth order. PROBLEM Definition Example NOTES C is the Sum of 4…

  • JADEs #25: Boussinesq PDE & Another

    JADEs #25: Boussinesq PDE & Another

    In this week's issue of JADEs, we explore two nonlinear partial differential equations, one a first order PDE and the…

    1 条评论

社区洞察

其他会员也浏览了