MIT 2.43 Advanced Thermodynamics, Spring 2024 - Lecture 22: Definition of “Heat&Diffusion” Interaction; Diffusive and Convective Fluxes

MIT 2.43 Advanced Thermodynamics, Spring 2024 Instructor: Gian Paolo Beretta View the complete course: https://ocw.mit.edu/courses/2-43-advanced-thermodynamics-spring-2024/ Complete course table of contents with hyperlinks to slides and video timestamps: https://ocw.mit.edu/courses/2-43-advanced-thermodynamics-spring-2024/resources/mit2_43_s24_toc_slides_pdf/ Complete course analytical index with hyperlinks to slides and video timestamps: https://ocw.mit.edu/courses/2-43-advanced-thermodynamics-spring-2024/resources/mit2_43_s24_index_slides_pdf/ YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP6309d0oJDiVo1CvxUQXJ2il This lecture covers: Balance equations for extensive properties of a continuum. Barycentric velocity. Diffusive and convective fluxes. Definition of heat&diffusion interaction. Relation between diffusive fluxes of energy, constituents, and entropy. Measurable heat flux. Instructor suggests to set viewing speed at 1.5 for faster learning. Slides for this lecture: https://ocw.mit.edu/courses/2-43-advanced-thermodynamics-spring-2024/resources/mit2_43_s24_lec22_pdf/ Key moments: 00:00:00 - Introduction 00:00:20 - Nonequilibrium in Heat, Mass, and Charge Transfer 00:00:45 - Heat Transfer vs Chemical Kinetics: Parallel Logic 00:11:10 - General Balance Equations for Extensive Properties 00:13:28 - Balance Equations for 1D Heat and Mass Transfer 00:21:41 - Rate of Change of an Extensive Property 00:30:54 - Diffusive and Convective Fluxes 00:42:46 - Collisions and Short and Long Range Forces 00:50:11 - General Balance Equation for an Extensive Property 00:54:43 - Definition of Barycentric Velocity 00:55:48 - Various Extensive Properties for a Continuum 00:56:54 - Continuum Assumption and Knudsen Number 01:03:45 - Local-Equilibrium Simple-System Bulk-Flow Relation 01:09:25 - Gibbs-Duhem Relation in Various Forms 01:10:59 - In Terms of Volume Specific Properties 01:13:25 - Generalization of the Concept of Heat Interaction 01:13:38 - Recall How We Defined “Heat Interactions”.. 01:15:54 - ..and Proved the Clausius Inequalities 01:17:49 - Same Logic Defines “Heat&Diffusion” Interactions.. 01:20:48 - ..and Generalizes the Clausius Inequalities 01:22:28 - Only a Fraction of the Energy Flux is Heat 01:30:55 - “Heat&Diffusion” Mode of Interaction in Continua License: Creative Commons BY-NC-SA More information at https://ocw.mit.edu/terms More courses at https://ocw.mit.edu Support OCW at http://ow.ly/a1If50zVRlQ We encourage constructive comments and discussion on OCW’s YouTube and other social media channels. Personal attacks, hate speech, trolling, and inappropriate comments are not allowed and may be removed. More details at https://ocw.mit.edu/comments.