What is Transport phenomena: Definition and 30 Discussions

In engineering, physics and chemistry, the study of transport phenomena concerns the exchange of mass, energy, charge, momentum and angular momentum between observed and studied systems. While it draws from fields as diverse as continuum mechanics and thermodynamics, it places a heavy emphasis on the commonalities between the topics covered. Mass, momentum, and heat transport all share a very similar mathematical framework, and the parallels between them are exploited in the study of transport phenomena to draw deep mathematical connections that often provide very useful tools in the analysis of one field that are directly derived from the others.
The fundamental analysis in all three subfields of mass, heat, and momentum transfer are often grounded in the simple principle that the total sum of the quantities being studied must be conserved by the system and its environment. Thus, the different phenomena that lead to transport are each considered individually with the knowledge that the sum of their contributions must equal zero. This principle is useful for calculating many relevant quantities. For example, in fluid mechanics, a common use of transport analysis is to determine the velocity profile of a fluid flowing through a rigid volume.
Transport phenomena are ubiquitous throughout the engineering disciplines. Some of the most common examples of transport analysis in engineering are seen in the fields of process, chemical, biological, and mechanical engineering, but the subject is a fundamental component of the curriculum in all disciplines involved in any way with fluid mechanics, heat transfer, and mass transfer. It is now considered to be a part of the engineering discipline as much as thermodynamics, mechanics, and electromagnetism.
Transport phenomena encompass all agents of physical change in the universe. Moreover, they are considered to be fundamental building blocks which developed the universe, and which is responsible for the success of all life on earth. However, the scope here is limited to the relationship of transport phenomena to artificial engineered systems.

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  1. Dario56

    Can diffusion be modelled as one-dimensional in this problem?

    I have a discussion with a colleague of mine. We have a thin cuboid sample whose two dimensions are similar to each other and are both much bigger than the sample thickness. I'm doing an experiment in which the diffusion of some species is induced and its diffusion profile is measured in one of...
  2. D

    Engineering Tubular Reactor with catalytic walls

    My attempt: Species fluid and solid phase balances for a tubular reactor in which there is a homogeneous first order reaction and a heterogeneous reaction on the external surface of non-porous catalyst coated along the reactor wall. Mole balance equation for the fluid phase The heterogeneous...
  3. S

    A Conservation Laws from Continuity Equations in Fluid Flow

    Consider a fluid flow with density ##\rho=\rho(t,x)## and velocity vector ##v=v(t,x)##. Assume it satisfies the continuity equation $$ \partial_t \rho + \nabla \cdot (\rho v) = 0. $$ We now that, by Reynolds Transport Theorem (RTT), this implies that the total mass is conserved $$...
  4. Dario56

    Onsanger and Stefan-Maxwell Equations

    Stefan-Maxwell and Onsanger equations are equations which can be used to calculate mole flux of the component due to different types of gradients. It is assumed that driving forces of mass transfer are in equilibrium with drag forces due to interaction of different types of components...
  5. jacobtwilliams001

    Intermolecular forces and Transport phenomena

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  6. Ahmed Naji

    A question about non-Newtonian fluids in a "Transport Phenomena" book

    In this topic >> https://www.physicsforums.com/threads/stress-tensor-for-non-Newtonian-fluid.860240/ Mr. Chestermiller replies that "For a purely viscous non-Newtonian fluid (not viscoelastic), you use exactly the same form of equation as for a Newtonian fluid (see Bird, Stewart, and...
  7. E

    I Pressure vs Normal Stress: Exploring Bird Transport Phenomena

    What's really the difference between pressure and normal stress? Also I know pressure acts normal to a surface from the outside Do normal stress acts from inside? I'm reading bird transport phenomena and this is confusing
  8. E

    Classical Bird's book "Transport Phenomena"

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  9. E

    I Derivation of the Onsager symmetry

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  10. A

    Why is solar radiation equal to long wavelength emission?

    In my heat transfer course, I always had to do analysis of long-wavelength radiation between surfaces first, and find the heat radiated from one of the surface. Then, solar radiation is added to the problem, and suddenly it was said that solar radiation=heat radiated from this surface! Does...
  11. Dr Eve Wildman

    A AC transport data query (using a PPMS system)

    Hello and thanks for looking at this question. I have a semi-conducting sample which has been run on a PPMS system - measuring it's resistivity as a function of temperature. I switched to AC transport mode in order to measure the resistivity again while applying frequencies between 1Hz -...
  12. W

    Reynolds Transport Theorem Derivation Sign Enquiry

    Hi, Our lecturer explained us the Reynold Transport theorem, its derivation , but I don't get where the - sign in control surface 1 comes from? He said that the Area goes in opposite direction compared with this system. I can't visualise this on our picture. Can you please help me understand...
  13. M

    Shell balances in cylindrical coordinates

    I have a question regarding writing a shell balance for a cylindrical system with transport in one direction (in any area of transport phenomena). When we set up the conservation equation(say steady state), we multiply the flux and the area at the surfaces of our control volume and plug them...
  14. W

    Understanding Fluid Flow and Stress in Two Dimensions with LaTex Tutorial

    Homework Statement Homework Equations 0=viscous+gravitational+pressure I saw in the solutions that pressure=0 in this case, but why? I also knew that : accumulation= flow in - flow out+generation, why not use this one? The Attempt at a Solution (their solution) We are interested in...
  15. H

    Classical BSL Transport Phenom. vs. BSLK Introductory Transport Phenom

    I'd like to purchase one of these books for self-study. The BSLK Introductory Transport Phenomena claims: "Devoting more space to mathematical derivations and providing fuller explanations of mathematical developments—including a section of the appendix devoted to mathematical topics—allows...
  16. P

    Classical Book recommendations for Boltzmann equation

    Im trying to learn transport processes and the Boltzmann transport equation. What books do you guys recommend for beginners? Thanks!
  17. W

    Heat transfer and Fluid Flow Struggling Problems

    Homework Statement Hello, I am struggling with this heat transfer and fluid flow problem.I would really appreciate if someone could have a look over what I have done on it. I am not sure if what I have done is correct ,I would really appreciate if you could tell me if it is correct or wrong.And...
  18. W

    Fluid Flow/Heat Transfer question struggle

    Homework Statement I would really appreciate if someone could help me out with this exercise in fluid flow/heat transfer ,because I really struggling with it.Below I am attaching photo of problem+table with values. Thank you in advance !Homework Equations Question link:[/B]...
  19. MexChemE

    Boundary layer thickness confusion

    Hi, PF! Recently, while reading chapter 6 of Incropera's Fundamentals of Heat and Mass Transfer I got into a confusion regarding the velocity boundary layer. The book first states that, as the flow becomes more turbulent, the boundary layer gets thicker, as indicated by both figures attached at...
  20. MexChemE

    Burning carbon particle -- Boundary conditions

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  21. MexChemE

    Two-bulb experiment for measuring gas diffusivity

    Hi, PF! I recently solved a problem from BSL which asked to analyze the following system used for determining the diffusivity of a binary mixture of gases. The left portion of the system, from the left bulb up to the stopcock at the middle of the tube, is filled with gas A. The right portion...
  22. MexChemE

    Diffusion -- Tarnishing of metal surfaces

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  23. MexChemE

    Difference between Thiele modulus and Damköhler number

    Hi, PF! In the study of mass transfer involving chemical reactions, I have seen the use of two different non-dimensional parameters which apparently quantify the same ratio. These are the second Damköhler number and the Thiele modulus, which are defined as \textrm{Da}^{\textrm{II}} =...
  24. MexChemE

    Shell balances in cylindrical coordinates

    Hello, PF! I have some doubts about setting up shell balances in a cylindrical geometry. Consider a fluid flowing down a vertical pipe. In order to perform the momentum balance, we take a cylindrical (annular) shell of length L and width Δr. The analysis of such system can be found in chapter 2...
  25. MexChemE

    Transport phenomena -- Direction of shear stress

    Greetings, PF! I have some questions regarding the problem I attached below. It is some sort of Couette flow variation. It's not homework, I'm just learning the basics of TP on my own. I fully solved the problem with the Navier-Stokes and continuity equations, using some assumptions in order to...
  26. G

    Torque due to static fluid- Transport Phenomena

    1. Homework Statement Calculate the torque on the dam about the origin (Picture attached) due to the pressure force of the fluid. Homework Equations Pressure force is correct (dF) The Attempt at a Solution [/B] I have solve it; however, I am not sure if I calculated over the origin asked...
  27. Astronuc

    Transport Phenomena by Bird, Stewart, Lightfoot

    Author: R. Byron Bird, Warren E. Stewart, Edwin N. Lightfoot Title: Transport Phenomena, Revised 2nd Edition [Hardcover] Amazon Link: https://www.amazon.com/dp/0470115394/?tag=pfamazon01-20 Prerequisities: Advanced Calculus, Differential Equations (ODE, PDE), Introductory Heat Transfer...
  28. C

    Transport phenomena or diffusion book for physical sciences

    I am a graduate student in physics. Can someone recommend a book that explores transport phenomena or diffusion from a physical sciences (instead of engineering) point of view? I would like that because I'm not dealing with industrial equipment and don't want to spend chapters wading through...
  29. V

    Solving Transport Phenomena in a Steady State System

    I am facing a problem on transport phenomena. Can anyone help me to solve this problem. I would really appreciate it. Its little urgent. I know that i have to use shell mass balance to start the problem but how to proceed further is what making me confused. In a beaker, a solid sphere of...
  30. A

    Transport phenomena - shell balance

    Homework Statement Use a shell balance method to derive the equation governing the two dimensional temperature distribution,u, in a circular disk in polar coordinate system(r,theta). allow for the possibility of differing thermal conductivities in the r and theta directions. Homework...