An experimental study was investigated on the effect of inclination conditions on flow instability in parallel rectangular channels within natural circulation systems. Findsings reveal that at 12 MPa, inclination along the narrow side causes vapor phase accumulation in the narrow section, intensifying vapor-liquid stratification and reducing pressure drop across the two-phase section. When the mass flow rate supplied by the natural circulation system to the rectangular channel is 500 kg/(m 2 ·s), increasing inclination angle reduces stability in parallel rectangular channels under natural circulation conditions, with a maximum decrease of 15%. When the mass flow rate supplied by the static natural circulation system to the rectangular channel is less than 345 kg/(m 2 ·s), increasing inclination angle gradually enhances stability in parallel rectangular channels under natural circulation conditions, with a maximum increase of 26%.
Lu et al. (Sun,) studied this question.