以截面尺寸为50 mm×2 mm的矩形并联双通道为实验本体,在系统压力为2~8 MPa范围内,开展强迫循环条件下的第一类密度波流动不稳定性实验研究。在实验参数范围内,获得系统压力(P)、质量流量(G)和入口过冷度(Tsub)等热工参数对流动不稳定界限参数的影响规律;在Npch-Nsub图上给出不稳定点的分布,最后基于实验数据拟合第一类密度波不稳定边界的经验关系式。 A rectangular parallel double channel with a cross section of 50 mm × 2 mm was used as the experimental body. The first type of density wave instability experiment under forced circulation was carried out at a system pressure of 2 ~ 8 MPa. In the range of experimental parameters, the influence laws of thermal parameters such as system pressure (P), mass flow (G) and inlet undercooling (Tsub) on the instability boundary parameters were obtained. In the Npch-Nsub diagram, Finally, based on the experimental data, we fit the empirical relationship of the first type of wave instability boundary.