Abstract: The orifice plate energy dissipation device known for its simple structure, high energy dissipation efficiency, and ease of assembly and disassembly, has been widely used in water conservancy projects in China. In the design of the multi-stage orifice plate energy dissipation device, a variable pore diameter aperture plate energy dissipation device is reconstructed. The energy dissipation efficiency, total resistance coefficient, and pressure path change of the device under different shrinkage angles, torsion angles, and Reynolds numbers are analyzed and studied by model tests. The findings suggest that, with constant torsion and contraction angle of the orifice plate remain, the energy dissipation rate of the device increases with the increase of Reynolds number. When the Reynolds number and contraction angle remain unchanged, both the energy dissipation rate and the total resistance coefficient also increase with the increase of the torsion angle. When the Reynolds number and torsion angle remain unchanged, the energy dissipation rate of the device decreases with the increase of contraction angle; In addition, under the same contraction angle and torsion angle, the pressure at the same measuring point increases with the increase of Reynolds number, and under the same Reynolds number, contraction angle and conditions, the pressure at the same measuring point also increases with the increase of torsion angle. In general, the most reasonable combination mode of the orifice plate of the energy dissipation device is the contraction angle of 30 ° and the torsion angle of 6 °.

Key words: dissipation rate, Reynolds number, torsion angle, angle of contraction, total drag coefficient