The model used for the following simulations was validated
against a cylindrical source model, as well as by comparison with
the models developed by Kujawa et al. [35] and Bu et al. [2]. A more
specific breakdown of the model validation is detailed in Templeton
et al. [34]. Additionally, the proposed model simplifies the velocity
profile of the fluid within the heat exchanger to a uniform profile.
This assumption was considered due to the laminar nature of the
flow, the relatively low fluid velocity, and comparison with results
obtained from implementing a parabolic velocity profile for the
fluid in the inner pipe and outer annulus.