“…They reported that the optimized oval-tube outperforms the conventional circular-tube shape by approximately 13% and 15% in heat transfer rates, 9% and 13.5% in coefficients of performance (COP), and 13% and 16.6% in heat transfer coefficients for Re = 1030 and 2060, respectively. Moreover, other investigations by numerical and experimental treatments have been carried out by Sakhri et al [42][43][44], Chamkha et al [45], Boursas et al [46], Chekchek et al [47], Hadidi et al [48], Menni et al [49][50][51][52], Ahmad et al [53], Salmi et al [54], Ameur et al [55], Mahammedi et al [56], Maouedj et al [57], etc. Their studies suggested different models of heat exchangers in order to improve the performance under various limit conditions.…”