In This Thesis, Different Heat Transfer And Boundary Layer Flow Problems Coupled With Heat Transfer, Thermodynamics And Electromagnetism Has Been Studied. rnProblems Concerning Heat Transfer In Fins And Thermal Explosion End Up In A Second Order Nonlinear Odes, Which Are Then Solved Using Numerical Method, Specifically The Shooting Secant Method. Dynamical Systems Analysis Is Also Studied For These Problems. rnBoundary Layer Flow Coupled With Heat Transfer, Thermodynamics And Electromagnetism, And Nano Fluid Flow Is Also Studied In This Thesis. They End Up In Highly Nonlinear Coupled Odes, Which Are Then Solved Using Numerical Method (Shooting Secant). rnBackground Of The Specific Problem Introduced In The Chapter, Together With The Mathematical Formulations Of Ythe Problem And Descriptions Of The Results Are Then Provided. The Description Based On The Physics Of The Problems Are Discussed In Detail For Each Chapters.