Transient heat transfer in the laminar thermal entry region of a pipe: an analytical solution

✍ Scribed by Sucec, James

• Publisher: Springer
• Year: 1986
• Tongue: English
• Weight: 426 KB
• Volume: 43
• Category: Article
• ISSN: 0003-6994
• DOI: 10.1007/bf00386039

✦ Synopsis

Attention is directed toward the problem of unsteady convective heat transfer to a fluid flowing inside a pipe in a laminar, fully developed fashion when suddenly, an ambient fluid outside the pipe undergoes a step change in temperature. For the fastest portion of the resultant transient, time domain I, an analytical solution of the governing partial differential thermal energy equation is effected via the Laplace transformation. From this solution, response functions are found for the pipe wall temperature, surface heat flux, and fluid bulk mean temperature as a function of non-dimensional time for a range of values of a parameter which characterizes the heat transfer between the ambient and the pipe.

Comparison of results is made with a recent finite difference solution in the literature and with the standard quasi-steady type of analysis. It is found that the analytical solution presented herein extends and complements the finite difference solution and that the quasi-steady solution can be severely in error in this part of the transient.