Tubular heater/exchanger, finite elements: numerical simulation (1)

Antonio Sala, UPV

Difficulty: **** ,       Relevance: ,      Duration: 13:59

*Enlace a Spanish version

Summary:

This video is a continuation of the video [tubulFE1EN], where it was shown how to introduce a (symbolic) finite element model of a tubular heater in Matlab, the heater is the object of a case study throughout multiple videos.

In this video, apart from briefly summarizing the video referred to in the first three minutes, we detail how to translate the problem from symbolic to numerical, how to define the inputs and how to integrate it with a numerical integrator. The execution times of ode15s and ode45 are compared, the former being advantageous in this case when the number of elements is large, see [ode45vs15sEN] for other comparisons of the two integrators (no one is better than the other in all cases).

The simulations seem generally satisfactory, although there are certain artifacts (high frequency oscillations during the delay time) when using the coefficient $\beta \approx 0.5$ in the model of each element, related to the Padé approximation of the delay in each of them.

The detail about these oscillations, and the influence of the number of elements and the value of $\beta$ on the simulation result are addressed in the video [tubulFEsim2EN], continuation of this one. It would also be interesting to watch the video [aproxretEN] on delay approximation (outside the case study) because its conclusions apply here, and they are similar to those obtained in the video [tubulFEsim2EN].

*Link to my [ whole collection] of videos in English. Link to larger [ Colección completa] in Spanish.