Analysis of laminar flow and heat transfer characteristics of fluid in plain and induced tubes

Heat energy is applied in various equipment and the pursuit to produce equipment that has an improved performance is increasing. In pursuit to augment heat transfer in such equipment for its better performance, it is necessary to induce the tubes of the equipment by integration of supplementary devices into them or modification of their geometries, and then analyse thermo-hydraulic characteristics of flow in the tubes. In this work, thermo-hydraulic characteristics of laminar flow in eight different tube models were numerically analysed. The models comprise tube without a tape inside it (Tube-P), plain-twisted-tape-induced tube (Tube-L), ellipse-shaped-opening-twisted-tape-induced tube (Tube-E), circle-shaped-opening-twisted-tape-induced tube (Tube-C), triangle-shaped-opening-twisted-tape-induced tube (Tube-T), intersected-axes-ellipse-shaped-opening-twisted-tape-induced tube (Tube-EX), intersected-axes-circle-shaped-opening-twisted-tape-induced tube (Tube-CX), and intersected-axes-triangle-shaped-opening-twisted-tape-induced tube (Tube-TX). The goal of the current work focuses on identifying the model among them whose performance is the most superior. Reynolds numbers of values between 830 and 2,000 were assigned to the laminar flow, and a CFD software known as Fluent was used to carry out the simulation of the thermo-hydraulic characteristics of the laminar flow. The findings revealed that the intersected axes and the geometry of the openings in the tapes have impacts on the models’ performance. The Tube-TX model’s performance is the most superior among all the models as its Nusselt number is 64.70 to 103.22% more than that in the Tube-L model. The friction factor in the Tube-TX model is 1.59 to 1.62 times the values in the Tube-L model. The heat transfer enhancement index of the Tube-TX model is 64.70 to 103.22% higher than that of the Tube-L model. The Nusselt number and friction factor obtained from the novel correlations formed in the current work and those obtained from the current work’s simulation are in accord with a variation of 4.08% and 1.10%, respectively.