The Simulation Research on Ultra-High-Pressure Water Jet for the Outer Wall of Spherical Tanks Using a Welding Grinding Robot

The welding seam of the outer wall of the spherical tank usually needs to be manually polished. The working environment is harsh, labor-intensive, and poses safety risks. Therefore, the demand for robot automation is extremely strong and urgent. The working principle of the external wall weld grinding robot involves supplying ultra-high-pressure water through the high-pressure pump. This causes the nozzle in the spray rod to jet out water with large pressure to polish the weld. It relies on the rotation of the spray rod combined with the robot climbing the wall to create a dense waterline and complete the rust removal function. Using the spherical tank wall climbing robot based on ultra-high-pressure water jet for welding seam polishing offers advantages such as efficiency, environmental, and automation. The flow field of ultra-high-pressure water jets was simulated by Fluent in two-dimensions. By focusing on the wall shear stress and pressure of the target surface as key parameters for weld polishing ability, the impact of the linear velocity of a single nozzle on the impact force distribution and strength of the target surface was investigated. The trajectory of multi-beam rotating nozzles is monitored, and the cumulative impact time of different scanning areas is calculated to coordinate parameters affecting the impact effect, such as nozzle position and robot moving speed. This study aims to provide insights for the design parameters of multi-beam rotating nozzles.