*2.5. Validation by Experimental Data*

The experimental data in [28] were used to verify the accuracy of the numerical method. The experiments were carried out to investigate the thermal performance of sCO2 in a straight channel with semicircular cross section. The hydraulic diameter and total length of the channel are 1.17 mm and 500 mm. The operating pressure, heat flux, and mass flux are 8.1 MPa, −20 kW/m2, and 330 kg/m2-s, respectively. As shown in Figure 4, the CFD simulation results and experimental data maintain a good consistency with the maximum relative error 17.1% over all analyzed *Tb* range, which covers the pseudocritical point. Thus, the numerical method adopted in this study for the flow and heat transfer performance of sCO2 in the semicircular channel is reliable and comparatively accurate.

**Figure 4.** Validation with experimental data [28].
