Research on flow rate engineering calculation model of U-pipes for fabricating transverse variable profiled (TVP) strips by simulation and experiment

Transverse variable profiled (TVP) strips have significant lightweight and functional characteristics due to the nonuniform section, but need to be cooled nonuniformly in order to obtain the uniform microstructure and performance. Hence, it has become the consensus of the industry to develop new on-line cooling equipment that can adjust and control the cooling capacity along the width direction (WD). Therefore, a multi-functional test platform was designed based on the U-pipes used in the industrial runout table cooling process. A steady-state Computational Fluid Dynamics (CFD) model was built based on the Fluent software, and the influence of the main pipe inlet pressure, U-pipe inner diameter, restrictor ring thickness, and restrictor ring inner diameter was analyzed. The results indicate that the flow rate increases as the U-pipe inner diameter increase when there is no restrictor ring, and the result is contrary when there is a restrictor ring. The influence of main pipe inlet pressure, restrictor ring thickness, and restrictor ring inner diameter on the flow rate is monotonic. Besides, the restrictor ring inner diameter has a wide flow rate adjusting range and has little impact on the equipment structure, which helps to reduce the reconstruction cost. Finally, considering the influence of geometric parameters, the flow rate engineering calculation models of the U-pipe were derived and verified, which lays the theoretical foundation to customize the flow rate distribution along the WD at the design stage.